Journal of Asthma
ISSN: 0277-0903 (Print) 1532-4303 (Online) Journal homepage: http://www.tandfonline.com/loi/ijas20
The development and test re-test reliability of a work-related asthma screening questionnaire Katie R. Killorn MSc, Suzanne M. Dostaler MSc, Jennifer Olajos-Clow MSc, Scott E. Turcotte MSc, Janice P. Minard MSc, D. Linn Holness MHSc, MD, Irena Kudla MHSc, CIH, Catherine Lemière MD, MSc, Teresa To PhD, Gary Liss MD, MS, Susan M. Tarlo MBBS & M. Diane Lougheed MD, MSc To cite this article: Katie R. Killorn MSc, Suzanne M. Dostaler MSc, Jennifer Olajos-Clow MSc, Scott E. Turcotte MSc, Janice P. Minard MSc, D. Linn Holness MHSc, MD, Irena Kudla MHSc, CIH, Catherine Lemière MD, MSc, Teresa To PhD, Gary Liss MD, MS, Susan M. Tarlo MBBS & M. Diane Lougheed MD, MSc (2015) The development and test re-test reliability of a work-related asthma screening questionnaire, Journal of Asthma, 52:3, 279-288 To link to this article: http://dx.doi.org/10.3109/02770903.2014.956892
Accepted online: 02 Sep 2014.Published online: 09 Sep 2014.
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Date: 22 September 2015, At: 12:53
http://informahealthcare.com/jas ISSN: 0277-0903 (print), 1532-4303 (electronic) J Asthma, 2015; 52(3): 279–288 ! 2014 Informa Healthcare USA, Inc. DOI: 10.3109/02770903.2014.956892
OCCUPATIONAL ASTHMA
The development and test re-test reliability of a work-related asthma screening questionnaire Katie R. Killorn, MSc1,2, Suzanne M. Dostaler, MSc1,2, Jennifer Olajos-Clow, MSc1,2, Scott E. Turcotte, MSc1,2, Janice P. Minard, MSc1,2, D. Linn Holness, MHSc, MD3,4,5,6, Irena Kudla, MHSc, CIH3,5,6, Catherine Lemie`re, MD, MSc7, Teresa To, PhD3,8, Gary Liss, MD, MS3,6, Susan M. Tarlo, MBBS3,4,5,6,9, and M. Diane Lougheed, MD, MSc1,2,6
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1
Asthma Research Unit, Kingston General Hospital, Kingston, Ontario, Canada, 2Division of Respirology, Department of Medicine, Queen’s University, Kingston, Ontario, Canada, 3Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada, 4Department of Medicine, University of Toronto, Toronto, Ontario, Canada, 5Department of Occupational and Environmental Health, St. Michael’s Hospital, Toronto, Ontario, Canada, 6The Center for Research Expertise in Occupational Disease, Toronto, Ontario, Canada, 7Service de Pneumologie, Hoˆpital du Sacre´ Coeur, Universite´ de Montre´al, Montre´al, Que´bec, Canada, 8Child Health Evaluative Sciences, The Hospital for Sick Children, Toronto, Ontario, Canada, and 9Respiratory Division, University Health Network, Toronto, Ontario, Canada
Abstract
Keywords
Objective: Work-related asthma (WRA) is under-recognized and delays in recognition contribute to long-term morbidity. The objective of the project was to develop a WRA screening questionnaire for use by primary care providers in the assessment of individuals with asthma, and to evaluate the respondent burden, test re-test reliability and face validity of the questionnaire. Methods: A literature search was undertaken and an expert advisory committee was convened. A questionnaire was drafted and assessed for feasibility of use and content validity. The study enrolled patients with asthma attending outpatient clinics and an asthma education center. Participants were asked to respond to the questionnaire on two occasions, and comment on the content (face validity) and ease of completion (respondent burden). Ethics approval was obtained from an institutional review board. Results: A 14-item selfadministered screening questionnaire was created. Thirty-nine participants were recruited, and 26 participants completed a second administration of the questionnaire. The items on the relation of asthma symptoms to work demonstrated substantial agreement between testings. The workplace exposures items were found to have good reproducibility. The majority of participants denied that items were repetitive, not useful or difficult to understand. Conclusions: We have developed a WRA screening questionnaire designed to aid primary care providers in the recognition of possible WRA. The tool exhibited content and face validity, good test re-test reliability and low respondent burden. Participant feedback is being considered in revisions of the questionnaire.
Occupational asthma, prevention, primary care, questionnaire, work-aggravated asthma, work-exacerbated asthma
Introduction Environmental factors play an important role in the origin and persistence of asthma [1]. As much as 25% of adults with asthma are estimated to have work-related asthma (WRA) [2]. WRA encompasses two subtypes of occupational respiratory diseases: occupational asthma (OA), which includes asthma induced by sensitizer or irritant work exposures; and work-exacerbated asthma (WEA), whereby pre-existing or concurrent asthma is worsened by work factors [2]. WRA is associated with poor health outcomes. Continued exposure to a causative agent in the workplace can lead to progressive deterioration of lung function, in Correspondence: Dr. M. Diane Lougheed, Division of Respirology, Department of Medicine, Queen’s University, 102 Stuart Street, Kingston, Ontario, Canada K7L 2V6. Tel: 613.548.2348. Fax: 613.547.1459. E-mail: [email protected]
History Received 28 March 2014 Revised 15 August 2014 Accepted 16 August 2014 Published online 9 September 2014
terms of forced expiratory volume in one second, non-specific hyper-responsiveness and symptoms [3]. However, many workers are left with permanent lung impairment despite removal from the offending agent [4]. It has been determined that early diagnosis and early avoidance of further exposure increase the likelihood of full recovery [5]. Delays in recognition contribute to long-term morbidity [6–9]. This literature is largely based on studies of patients with OA. Similar findings of improvement after cessation have been found for patients with WEA, but to a lesser extent [10,11]. Adults with asthma are primarily cared for by their family physicians [12]. Family physicians and respirologists report lack of knowledge, time and expertise as main barriers to early recognition of WRA [13,14]. Questionnaires have been identified as a means of identifying individuals with WRA [13,15]. To our knowledge, a screening questionnaire to
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aid in the identification of individuals with possible WEA and/or OA, designed specifically for use in the primary care setting does not exist. In 2002, the Government of Ontario funded a provincial ‘‘Asthma Plan of Action’’ in an effort to increase the implementation of the Canadian Thoracic Society’s Asthma Guidelines [16]. One of the initiatives that developed from this action plan was the Primary Care Asthma Program (PCAP), an evidence- [16] and outcomes- [17] based asthma care program implemented in 12 primary care sites with multiple locations across Ontario. Tools such as the Ontario Lung Association Asthma Care Map (ACM) are used within PCAP sites. The ACM is a template for asthma management that includes seven WRA screening questions. The first objective of this study was to develop a selfadministered WRA screening questionnaire for use by primary care providers in the assessment of individuals with confirmed asthma. For PCAP sites, this questionnaire would be used as a means of prompting a more detailed occupational history of patients answering affirmatively to one of the WRA screening items on the ACM. A stand-alone version of the questionnaire would be created for non-PCAP primary care sites not using the ACM already. The second objective was to examine the respondent burden, face validity, and test re-test reliability of the screening questionnaire.
Methods Literature search and development The American College of Chest Physicians Consensus Statement on WRA [2] was consulted and a search of databases and websites was undertaken (Table 1). The objective of this search was to compile existing WRA instruments and items, published studies assessing the validity and reliability of these instruments and items, and a comprehensive list of offending inhalation exposures, as resources in the development of the screening questionnaire. An Advisory Committee (AC) consisting of nine members including respiratory medicine providers, occupational lung disease experts, primary care practitioners and epidemiologists was convened to provide expert feedback throughout the development process. Instruments containing items relating to occupation and exposure were compiled. Further, a list of potential offending agents provided by the expert panel was supplemented and categorized. A questionnaire was drafted Table 1. Literature and internet search terms. Search terms Question* AND occupation* asthma Work AND asthma Exposure AND asthma
Work-related asthma question* Work-related asthma
and assessed for content validity (whether the questionnaire adequately samples the intended domain of content, often assessed through expert review [18]), as well as feasibility of use by the AC members. Study design and population A study was conducted to assess the test-retest reliability, face validity and respondent burden of the questionnaire. This study aimed to enroll at least 30 patients with asthma attending specialist outpatient clinics (respirology) and an asthma education center. This asthma education center received patients referred from both primary care providers and specialists. Patients were eligible if they were Englishspeaking, of working age (18–65 years) and had a diagnosis of asthma (doctor diagnosis, confirmed with objective measures [16]). Further, they had to be able to give consent, and be available to respond to a mailed second questionnaire 1 month after recruitment. The clinical care provider identified eligible patients from the clinic attendance lists. The research associate introduced the study and gathered written informed consent if the patient was interested in participating. Participants were asked to respond to the questionnaire (paper-version) on two occasions. Participants completed the first questionnaire unaided in clinic. Two to four weeks later, they received and returned their second questionnaire by mail. If questionnaires were not returned within a 3-week delay, a single reminder telephone contact was attempted. In addition to the WRA screening questionnaires, participants were given a separate paper survey to complete on both occasions. This survey collected demographic information (gender, age, education level, age at which a doctor first told them they had asthma). Face validity is the appropriateness, sensibility, or relevance of a test and its’ items to the responder of that test [19]. In order to assess this, participants were asked to comment on the content of the WRA screening questionnaire (whether questions were ‘‘repetitive or not useful’’) and to suggest other questions for inclusion. Respondent burden was assessed by asking participants to comment on the ease of use (whether questions were ‘‘difficult to understand’’) and for the time it took to complete. Last, participants were asked to self-report whether their asthma was caused or aggravated by their work. Ethics approval for the study was obtained from the Queen’s University Health Sciences and Affiliated Teaching Hospitals Research Ethics Board. Statistical analysis
Database/search engine Cochrane Library Health and Psychological Instruments ISI Web of Science Medline (Ovid, PubMed) (Lim: 1975, adult) Google Scholar NIOSH
NIOSH, National Institute for Occupational Safety and Health. *Truncation symbol, retrieves all terms that begin with a given text string.
Univariate analyses were conducted to describe study sample characteristics, as well as screening questionnaire and survey responses. As part of the test re-test reliability analyses, the characteristics of those who completed two questionnaires were compared to those participants who completed one questionnaire (lost to follow-up). The two-sample t test for independent samples was used to test differences between samples on continuous participant characteristic variables, once normality of variables was established using the Shapiro–Wilk test. The Pearson’s chi-square test with Yates correction for continuity was used to test
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differences between samples on discrete participant characteristic variables. For contingency tables with expected cell counts of less than five, Fisher’s exact test was applied for the computation of p values. Cohen’s Kappa was computed to assess the test re-test reliability of questionnaire items with dichotomous outcomes (Y/N). Multiple choice exposure items were converted into continuous variables (scores) by separately summing the number of past and current exposure items. These items were assessed for test re-test reliability by computing the intra-class correlation coefficient (ICC) (1, 1). For all Kappa and ICC statistics, 95% confidence intervals were computed and tests of significance were conducted against a level of agreement or reliability of zero. A significance level (a) of 0.05 was chosen for all analyses. Statistical procedures were conducted using IBMÕ SPSSÕ for Windows (Version 20.0, Armonk, NY).
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Results Literature and Internet search findings Table 2 presents the 10 instruments containing occupation and/ or exposure items that were assembled from the literature and internet search. Two of the 10 tools were designed for clinical purposes. The first was a general work health screening tool used in an occupational health clinic at St. Michael’s Hospital, Toronto [20] and the second was a list of assessment questions for care providers to use in the assessment of asthma that is made worse at work created by the National Heart, Lung, and Blood Institute of the National Institutes of Health [21]. Neither had been assessed for validity. Two of the tools found in the search were specific to WRA surveillance programs. One was used as a means of characterizing and classifying WRA cases reported in a surveillance system in Washington State [22] and the other was used for physician reporting of WRA cases as part of the Ontario WRA Surveillance project [23]. Further, two instruments of the search were designed specifically for etiological research in occupational
populations. The first was an extensive questionnaire designed for research on asthma in healthcare workers that was developed by researchers at the University of Texas Health Science Center at Houston. It was formally tested for validity and reliability [24], although items related to time of asthma onset, worsening of asthma symptoms with work and amelioration of asthma symptoms when away from work were not specifically validated. The second tool was an occupational questionnaire from the National Institute for Occupational Safety and Health that has been used to assess the occurrence of asthma among at-risk occupational groups and contains an extensive number of items on symptoms and exposures [25]. The rest of the instruments were standard respiratory health questionnaires used for epidemiological research purposes that included work-related items [26–29]. To our knowledge, these have not been validated to predict WRA or to distinguish between non-WRA and WRA. The selected instruments provided over 70 items exhibiting considerable overlap. The items were categorized to reflect seven concepts: asthma diagnosis, education, workplace exposures (agents, duration, frequency, level), occupation history, relation of asthma symptoms to occupation, symptomatic co-workers, and seasonal variation in asthma symptoms. A list of 21 categories of known offending exposure agents was compiled. Questionnaire After an iterative editing process, two versions of the WRA screening questionnaire were prepared. The first was a one-page tool designed to supplement the seven WRA screening questions in the ACM in use at PCAP sites, titled the WRA Screening Questionnaire (short-version). The second was the full screening questionnaire, titled the WRA Screening Questionnaire (Long-version) [WRASQ(L]) (Figure 1), which included the WRA screening questions from the ACM and consequently, was intended for use in primary care sites not employing the ACM.
Table 2. Ten resulting instruments from the literature and internet search.
1 2 3 4 5 6 7 8 9 10
Instrument
Source
Current Work/Health/Exposure Tool Expert Panel Report 3: Guidelines for the Diagnosis and Management of Asthma Work-related Asthma Follow-Up Worker Questionnaire OWRAS Chart Abstraction Form A Survey of Asthma in Health Professionals
St. Michael’s Hospital, Toronto, Canada. [20] NHLBI of the NIH, USA. [21]
Initial Questionnaire of the NIOSH Occupational Asthma Identification Project ATS-DLD-78 Respiratory Questionnaire European Community Respiratory Health Survey Questionnaire for the Epidemiological Study on the Genetics and Environment of Asthma, Bonchial Hyper-responsiveness and Atopy St. George’s Respiratory Questionnaire
281
Washington State Labor and Industries, USA. [22] To et al., University of Toronto, Canada. [23] Delclos et al., University of Texas Health Science Center at Houston, USA. [24] Division of Respiratory Disease Studies, NIOSH, USA. [25] ATS and the DLD of the NHLBI (NIH), USA. [26] Burney et al., United Medical and Dental Schools of Guy’s and St Thomas’ Hospitals, London, UK. [27] Kauffman et al., Institut National de la Sante´ et de la Recherche Me´dicale, France. [28] Jones et al., St. George’s University of London, UK. [29]
NHLBI, National Heart, Lung and Blood Institute; NIH, National Institutes of Health; OWRAS, Ontario Work-related Asthma Surveillance; NIOSH, National Institute for Occupational Safety and Health; ATS, American Thoracic Society; DLD, Division of Lung Diseases.
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This 14-item questionnaire spanned one and a half pages and was based on three concepts: job type and employment duration (three items), relationship of symptoms (eight items), as well as exposures and exposure avoidance (three items). The items also present on the ACM were items 1, 4 to 6, 11 and 12, although, the occupation (item 1) and exposure (item 12) items had different response formats than the WRASQ(L) and item 11 was split into two separate questions on the ACM. The WRASQ(L) was used in the current study, and consequently, the remainder of this report will refer to this longversion.
Figure 1. The work-related asthma screening questionnaire (long-version).
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Sample characteristics Thirty-nine participants were recruited in this study. Characteristics of this sample are presented in Table 3. When participants were asked if their asthma was caused or aggravated by their work environment on the additional survey, 41.7% responded ‘‘yes’’. Current occupations encompassed all major industry types under the Statistics Canada National Occupational Classification for Statistics (NOC-S 2006) [30], except the ‘‘primary industry’’ category.
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Figure 1. Continued.
Test re-test reliability All 39 study participants completed the WRASQ(L) once. A total of 26 of the 39 participants completed the WRASQ(L) a second time, and the remaining 13 participants were lost to follow-up. Table 4 compares the participants who completed the WRASQ(L) once (n ¼ 13) to those who completed it twice (n ¼ 26). Although the test re-test sample was slightly older, comprised of more females and had a smaller percentage of participants reporting asthma that is caused or aggravated by the workplace, there were no statistically significant (p50.05) differences between groups. The number of days between the first and second
administrations of the questionnaire ranged from 16 to 63 d, with a mean of 33.7 d (SD, 13.4). There were two changes in employment (occupation type, and/or status) between the first and second administration of the WRASQ(L). Table 5 presents the results of the test re-test reliability analysis for items 4 to 14 of the WRASQ(L). Missing values were considered as non-affirmative responses in this analysis. Of those items assessed for agreement using Cohen’s Kappa statistic, the majority ranged from 0.42 to 0.77, while the lowest value was 0.28 for item 14 (use of protective measures). Concerning reproducibility, the ICC value for the count of workplace exposures was 0.74 for current, and 0.78 for past.
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Table 3. Study sample characteristics. N ¼ 39
n
Mean, SD
Median (Range)
Age Age at diagnosis Years at current job
39 39 35
47.3, 12.3 30.7, 18.3 12.3, 11.4
48 (19–68) 32 (1–64) 7 (0.5–42)
N ¼ 39
n
Categories
%a
Gender
39
Education
38
Employment
39
Asthma aggravated or caused by workb
36
Female Male Less than or some high school High school graduate Technical training Some college or university College or university graduate Post-graduate study Full-time Part-time Retired Off work Other Yes No Unknown
53.8 46.2 10.5 18.4 2.6 18.4 39.5 10.5 51.3 17.9 12.8 12.8 5.1 41.7 25.0 33.3
a
Totals may not add up to 100% due to rounding error. ‘‘Asthma aggravated or caused by work’’ was self-reported in response to an item on the participant survey (separate from the Work-related Asthma Screening Questionnaire [Long-version]).
b
Table 4. A comparison of participants who completed one WRASQ(L) and participants who completed two WRASQ(L)s. Completed 1 WRASQ(L) (n ¼ 13)
Completed 2 WRASQ(L)s (n ¼ 26)
Characteristic
n
Mean, SD
Median (Range)
n
Mean, SD
Median (Range)
p Valuea
Age (years) Age at diagnosis
13 13
44.9, 14.1 29.4, 17.9
47 (19–68) 32 (1–64)
26 26
48.6, 11.4 31.4, 18.8
48.5 (23–64) 31.5 (1–60)
0.380 0.757
Characteristic
N
%
N
%
p Valueb
Female Asthma aggravated or caused by workc some college or universityd
13 13 12
26 23 26
61.5 39.1 69.2
0.307 0.953 1.000
38.5 46.2 66.7
a
Two-sample t test for independent samples. Pearson chi-square test, with yates correction for continuity. ‘‘Asthma aggravated or caused by work’’ was self-reported in response to an item on the participant survey (separate from the Work-related Asthma Screening Questionnaire [Long-version]). d Fisher’s exact test. b c
Face validity and respondent burden These results are based on combined participant responses from both the first (N ¼ 39) and second (n ¼ 26) feedback surveys, with repetitive answers from the same participant removed. In terms of face validity, six participants listed items as ‘‘repetitive’’ or ‘‘not useful’’. None of these comments were relevant for revision (e.g. ‘‘not applicable to my employment’’). As general comments, two participants listed they were retired and two participants reported they worked from home, with the common concern that this questionnaire might not apply to them. Twenty-one participants suggested additional topics for inclusion on the WRASQ(L). While applicable to asthma care, the majority of these suggestions did not align with the purposes of a
succinct screening questionnaire for WRA in primary care, as determined by expert (author) review. Of note, participants suggested the tool include the following exposures: ‘‘stress’’ (n ¼ 5), ‘‘perfumes’’ (n ¼ 2), and ‘‘physical labor’’ (n ¼ 1). Two participants suggested the inclusion of an item inquiring about the triggers or causal factors related to their asthma. In terms of respondent burden, 10 participants stated they did not know what isocyanates were. Five participants listed other items/concepts as ‘‘difficult to understand’’, and only comment was relevant for a revision. This participant suggested that item 14 specify whether protective measures are used currently, or in the past. The first administration required on average 7.2 min (n, 32 (missing 7); SD, 3.8; range, 2–20), and the second administration required on average 6.5 min (n, 26; SD, 3.6; range, 2–15).
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Table 5. Test re-test reliability of items 4–14 on the WRASQ(L). (n ¼ 26)
Time 2
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Items 4
Did your asthma symptoms start at work?
5
Did your asthma symptoms start in days of a spill or fire at work?
6
Did your asthma symptoms worsen at work?
7
Do your asthma symptoms worsen on first day back to work?
8
Do your asthma symptoms worsen during the work day?
9
Do your asthma symptoms worsen at home after work?
10
Do your asthma symptoms worsen throughout work week?
11
Are chest symptoms different (less) on days off work and/or holidays?
14
Are protective measures used?
Time 1
N
Y
N Y N Y N Y N Y N Y N Y N Y N Y N Y
20 1 26 0 12 3 18 3 12 4 19 1 13 4 13 3 11 4
1 4 0 0 0 11 1 4 1 9 3 3 3 6 0 10 5 6
Kappa (95% CI)
p Valuea
0.75 (0.43, 1.08)
50.001
n/a
n/a
0.77 (0.53,1.01)
50.001
0.57 (0.20, 0.94)
0.003
0.62 (0.32, 0.91)
0.001
0.51 (0.10, 0.92)
0.007
0.42 (0.06, 0.78)
0.031
0.77 (0.53, 1.01)
50.001
0.28 (0.09, 0.65)
0.149
Mean ± SD
12 13
Number of current exposures Number of past exposures
Time 1
Time 2
5.5 ± 4.4 7.3 ± 4.7
5.8 ± 4.8 7.7 ± 4.9
ICC (95% CI) 0.74 (0.51–0.87) 0.78 (0.58–0.90)
p Valuea 50.001 50.001
a
Tested against a minimum level of agreement or correlation of 0. ICC, intra-class correlation coefficient.
Discussion Main findings We developed a WRA screening questionnaire with content and face validity, good test re-test reliability and low respondent burden. A striking 40% of participants (albeit a select group) self-reported that their asthma was caused or aggravated by the work environment. Although we cannot generalize from their experience, this may provide rationale for potential benefit of implementing evidence-based tools that prompt and enable clinical care providers to assess for possible WRA. In terms of test re-test reliability, characteristics of participants who were lost to follow-up did not differ significantly (p50.05) from those who completed the second WRASQ(L). Questionnaire items on the relation of asthma symptoms to work were found to have ‘‘moderate’’ to ‘‘substantial’’ agreement [31]. Of those items, the ‘‘start at work’’, ‘‘worsen at work’’, and ‘‘different (less) on days off work and/or holidays’’ items demonstrated the highest agreement between testings. The item inquiring about the use of protective measures in the workplace demonstrated the lowest stability (‘‘fair agreement’’ [31]) and the reason for this is unknown. The current and past workplace exposure items demonstrated ‘‘good’’ and ‘‘excellent’’ reproducibility [32], respectively. Overall, the majority of participants denied that items were repetitive, not useful or difficult to understand. This tool demonstrated low respondent burden and good face validity. The comments and suggestions made by participants were addressed in the following ways. First, there was marked confusion over the term ‘‘isocyanates’’. Those truly
exposed to this material are likely to be familiar with this term, due to strict regulations on the use of this material in the workplace. However, to address this concern, future implementation plans will include access to explanations for potentially confusing terms such as isocyanates, and the difference between a mask and respirator. Patients would be permitted to ask a health care professional for clarification. Additionally, we propose to add ‘‘help’’ icons beside terms on the electronic version of the WRASQ(L) that has been developed since this study was completed. Second, a revision to item 14 (use of protective equipment) will be made to clarify the time frame (present versus past). Third, it will be specified in item three that ‘‘employment status’’ includes those who are self-employed or working from home, and a separate ‘‘retired’’ response category will also be created. For those selecting ‘‘retired’’ or ‘‘off work due to respiratory health’’, the tense of ensuing questionnaire items will automatically be adjusted from current to past on the electronic WRASQ(L). Finally, the addition of exposures (‘‘exercise’’, ‘‘perfumes/scents’’, and ‘‘stress’’), and an item related to known causal or exacerbating work exposures, are being considered in revisions of the WRASQ(L). Although ‘‘stress’’ is a recognized trigger of asthma, it is not considered to be an occupational agent and the degree to which it triggers asthma is somewhat controversial. Strengths and limitations As mentioned previously, we are not aware of another screening questionnaire for both WEA and OA, designed specifically for use in the primary care setting. By prompting a detailed history of employment and exposures, this
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questionnaire may lead to improved recognition of WRA in primary care. A limitation of this study is the low number of participants that completed a second administration of the WRASQ(L). This resulted in wide confidence intervals around the test re-test reliability estimates, including negative lower limits. The well-cited Dillman survey method states that nonresponders should be followed-up 1 week after the initial mail-out with a reminder postcard, and 3 and 7 weeks after the initial mail-out with replacement questionnaires [33]. In this study, a single reminder phone call was attempted 1 week after initial mail-out, which may have affected response rates. Other limitations of the study relate to potential sources of measurement error in the test re-test reliability estimates. First, the number of days between administrations of questionnaire ranged from 16 to 63 d (mean, 33.7), while the recommended amount of time between testings is 2 weeks to 1 month [34]. Test re-test reliability estimates may have been underestimated due to slightly prolonged time between administrations. Second, a change in employment status or occupation between the two administrations of the tool may have inappropriately underestimated the test re-test reliability estimates since true changes may have occurred. However, only two participants reported a change in occupation and/or employment status between testings. Third, estimates of test re-test reliability may have been affected by the different locations of each questionnaire administration (clinic versus home). While it is important to acknowledge these potential sources of measurement error, the test re-test reliability of the WRASQ(L) is acceptable.
occupational lung disease clinic for suspected OA [42]. Specific questions addressed by physicians in the assessment of OA have also been validated in workers referred to specialist care settings for suspected OA. In fact, four of the eight symptom items on the WRASQ(L) have been tested in such studies. The sensitivity and specificity of such items are presented here based on calculations from the publications. A version of the ‘‘worsen throughout the work week’’ item was found to have a sensitivity of 15% and a specificity of 84% [43], while iterations of the ‘‘worsen at home after work’’ item have been found to have a sensitivity of 69% and a specificity of 27 to 46% [38,43]. The items with the highest sensitivity are versions of the ‘‘worsen at work’’ (sensitivity, 90–91%; specificity, 9–14%) [38,43] and ‘‘different (less) on days off work/holidays’’ (sensitivity, 74–88%; specificity, 24–57%) [38,43] items. The symptom items on the WRASQ(L), as well as combinations of these items, need to be evaluated in a formal validation study of the diagnosis of both OA and WEA in unselected asthma patients in a primary care setting.
Interpretation of findings in relation to relevant studies
Conclusions
The study sample was predominantly female and middleaged, which is characteristic of adult asthma in Canada [35]. Interestingly, a substantial percentage of participants in this sample were highly educated. Although this demographic distribution is comparable with reports of attendees of outpatient asthma education programs [36,37], these results may not be generalizable to other adult asthma populations. Specifically, the education level of the sample may have affected the results related to respondent burden and face validity. A larger group of less educated workers should be studied. Given the recruitment setting, the majority of participants in this study were followed by respirologists. Clinical history (judgment) of respirologists and occupational medicine specialists has been found to be highly sensitive in the diagnosis of OA [38–41]. However, there may be ample opportunity to increase the sensitivity of clinical judgment in relation to WRA diagnosis in primary care. Subsequent studies assessing the WRASQ(L) will take place within its intended primary care setting. Since this study was completed, Pralong et al. reported on a self-administered, 11-item, OA-specific Screening Questionnaire (OASQ-11). A model of eight of the questionnaire items, along with age and exposure duration, was able to correctly classify 80% of workers referred to a tertiary care
Implications for future research and practice The use of an electronic version of the WRASQ(L) is currently being evaluated in a primary care asthma program. Criterion validity and effectiveness of this as a tool to alert physicians to possible WRA will need to be assessed in a prospective study. Once validated and incorporated into standard practice, this questionnaire is expected to increase recognition of WRA, prompt adherence with evidence-based guidelines for the management of WRA, and facilitate timely, accurate adjudication of compensation claims.
We have developed a 14-item, self-administered screening questionnaire [WRASQ(L]) designed to increase the recognition of possible WEA and OA in the primary care setting. The WRASQ(L) exhibited content and face validity, good test re-test reliability and low respondent burden. Future directions include revision of this tool based upon these findings and findings from a pilot implementation in primary care currently underway, and a prospective validation of this tool with respect to both WEA and OA.
Acknowledgements We would like to acknowledge Dr. Patti Groome for contribution to these statistical methods. We would also like to acknowledge Dr. Peter Bell for his feedback in the development of the WRASQ(L) as well as research assistant Kendra Barrick, for her assistance in the assembly of instruments in the literature search.
Declaration of interest The authors alone are responsible for the content and writing of the article. The test re-test reliability analysis in this article is based on statistical methodology developed by K.R.K. as part of an academic thesis in the Department of Public Health Sciences at Queen’s University, Kingston, Ontario (supervisors: M.D.L., Dr. Patti Groome).
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DOI: 10.3109/02770903.2014.956892
K.R.K., S.M.D., S.E.T., J.P.M., C.L., and T.T. report no conflicts of interest. J.O.C. has received an honorarium from Takeda Canada for conducting a workshop on inhalation devices for asthma medication to primary care practitioners. D.L.H. has received peer-reviewed research funding from the Ontario Ministry of Labor, the Ontario Workplace Safety and Insurance Board (WSIB), and the Social Sciences and Humanities Research Council. I.K. has received peerreviewed research funding from the Ontario Ministry of Labor and the Ontario WSIB. G.L. has received research funding as an investigator from the Ontario WSIB Research Advisory Council, which supported research assistants and data analyses, but no funding went to the investigators. S.M.T. has received previous funding for research studies on WRA from the Ontario WSIB, the Worker’s Compensation Board (WCB) of Manitoba, and WorkSafe BC, and has performed clinical consultations of patients at the request of the Ontario WSIB. M.D.L. has received research funding from the Government of Ontario, the Ontario Lung Association, MPEX Pharmaceuticals, Pharmaxis Ltd., AllerGen NCE Inc. (the Allergy, Genes and Environment Network), the Ontario Thoracic Society, the Canadian Cystic Fibrosis Foundation, Queen’s University, Glaxo Smith Kline Inc., Janssen Inc., and speaker honoraria from the Ontario Lung Association. G.L., C.L., T.T. and S.M.T. were co-investigators with MDL on the WRA and Allergy Prevention and Early Detection (WRAAPED) Research Program team grant, supported by AllerGen NCE Inc. The work completed for this specific project was funded by both AllerGen NCE Inc. (grant number #07C4) and the Ontario WSIB.
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13. 14. 15. 16.
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18. 19. 20.
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References 1. Busse WW, Lemanske Jr RF,. Asthma. New Engl J Med 2001;344: 350–362. 2. Tarlo SM, Balmes J, Balkissoon R, Beach J, Beckett W, Bernstein D, Blanc PD, et al. Diagnosis and management of work-related asthma: American College of Chest Physicians Consensus Statement. Chest 2008;134:1S–41S. 3. Beach J, Rowe BH, Blitz S, Crumley E, Hooton N, Russell K, Spooner C, et al. Diagnosis and management of work-related asthma: summary. Rockville (MD): Agency for Healthcare Research and Quality (US); 2005 Report No.: Report No.: 06E003-1. 4. Rachiotis G, Savani R, Brant A, MacNeill SJ, Newman Taylor A, Cullinan P. Outcome of occupational asthma after cessation of exposure: a systematic review. Thorax 2007;62:147–152. 5. Nicholson PJ, Cullinan P, Taylor AJN, Burge PS, Boyle C. Evidence based guidelines for the prevention, identification, and management of occupational asthma. Occup Environ Med 2005;62: 290–299. 6. Chan-Yeung M, MacLean L, Paggiaro PL. Follow-up study of 232 patients with occupational asthma caused by western red cedar (Thuja plicata). J Allergy Clin Immunol 1987;79:792–796. 7. Rosenberg N, Garnier R, Rousselin X, Mertz R, Gervais P. Clinical and socio-professional fate of isocyanate-induced asthma. Clin Allerg 1987;17:55–61. 8. Tarlo SM, Banks D, Liss G, Broder I. Outcome determinants for isocyanate induced occupational asthma among compensation claimants. Occup Environ Med 1997;54:756–761. 9. Wheeler S, Rosenstock L, Barnhart S. A case series of 71 patients referred to a hospital-based occupational and environmental medicine clinic for occupational asthma. West J Med 1998;168: 98–104. 10. Pelissier S, Chaboillez S, Te´olis L, Lemiere C. Outcome of subjects diagnosed with occupational asthma and work-aggravated
22.
23.
24. 25.
26. 27. 28.
29. 30.
287
asthma after removal from exposure. J Occup Environ Med 2006; 48:656–659. Lemiere C, Forget A, Dufour MH, Boulet LP, Blais L. Characteristics and medical resource use of asthmatic subjects with and without work-related asthma. J Allergy Clin Immunol 2007;120:1354–1359. To T, Gershon A, Tassoudji M, Guan J, Chengning W, Estrabillo E, Cicutto L. The burden of asthma in Ontario. ICES investigative report. Toronto (ON): Institute for Clinical Evaluative Sciences (CA); 2006 Sept. 44 p. Holness DL, Tabassum S, Tarlo SM, Liss GM, Silverman F, Manno M. Practice patterns of pulmonologists and family physicians for occupational asthma. Chest 2007;132:1526–1531. Parhar A, Lemiere C, Beach JR. Barriers to the recognition and reporting of occupational asthma by Canadian pulmonologists. Can Respir J 2011;18:90–96. Walters GI, McGrath EE, Ayres JG. Audit of the recording of occupational asthma in primary care. Occup Med (Lond) 2012;62: 570–573. Lougheed MD, Lemie`re C, Dell SD, Ducharme FM, Fitzgerald JM, Leigh R, Licskai C, et al. Canadian Thoracic Society Asthma Management Continuum – 2010 Consensus Summary for children six years of age and over, and adults. Can Respir J 2010;17:15–24. To T, Cicutto L, Degani N, McLimont S, Beyene J. Can a community evidence-based asthma care program improve clinical outcomes?: a longitudinal study. Med Care 2008;46: 1257–1266. Coolidge FL, Segal DL. Validity. The Corsini Encyclopedia of Psychology: John Wiley & Sons, Inc.; 2010:1–2. Holden RR. Face validity. The Corsini Encyclopedia of Psychology: John Wiley & Sons, Inc.; 2010:1–2. Department of Occupational and Environmental Health, St-Michael’s Hospital. Work/health exposure screening tool. St-Michael’s Hospital. Available from: http://www.stmichaelshospital.com/programs/occupationalhealth/resources.php [last accessed 25 Jun 2009]. National Asthma Education and Prevention Program, Third Expert Panel on the Diagnosis and Management of Asthma. Expert Panel Report 3: guidelines for the diagnosis and management of asthma. Bethesda (MD): National Heart, Lung and Blood Institute (US); 2007 Aug. 417 p. Report No.: 07-4051. Anderson NJ, Reeb-Whitaker CK, Bonauto DK. Work-related asthma in Washington state: a summary of SHARP’s asthma surveillance data from 2001-2009. Olympia (WA): Safety and Health Assessment and Research for Prevention (SHARP) Program, Washington State Department of Labor and Industries (US); 2010 Report No.: 64-13-2010. To T, Tarlo SM, McLimont S, Haines T, Holness DL, Lougheed MD, Liss GM, et al. Feasibility of a provincial voluntary reporting system for work-related asthma in Ontario. Can Respir J 2011;18:275–277. Delclos GL, Arif AA, Aday L, Carson A, Lai D, Lusk C, Stock T, et al. Validation of an asthma questionnaire for use in healthcare workers. Occup Environ Med 2006;63:173–179. NIOSH Division of Respiratory Disease Studies. Initial Questionnaire of the NIOSH Occupational Asthma Identification Project. Centers for Disease Control and Prevention. Available from: http://www.cdc.gov/niosh/asthwww.txt [last accessed 25 Jun 2009]. Ferris BG. Epidemiology standardization project (American Thoracic Society). Am Rev Respir Dis 1978;118:1–120. Burney PG, Luczynska C, Chinn S, Jarvis D. The European Community Respiratory Health Survey. Eur Respir J 1994;7: 954–960. Kauffmann F, Annesi-Maesano I, Liard R, Paty E, Faraldo B, Neukirch F, Dizier MH. [Construction and validation of a respiratory epidemiological questionnaire]. Rev Mal Respir 2002; 19:323–333. Jones PW, Quirk FH, Baveystock CM. The St George’s Respiratory Questionnaire. Respir Med 1991;85:25–31. Statistics Canada. National Occupational Classification–statistics (NOC-S) 2006 statistics Canada. Available from: http://www. statcan.gc.ca/subjects-sujets/standard-norme/soc-cnp/2006/ noc2006-cnp2006-menu-eng.htm [last accessed 25 Jun 2009].
288
K. R. Killorn et al.
Downloaded by [ECU Libraries] at 12:53 22 September 2015
31. Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics 1977;33:159–174. 32. Fleiss JL. The design and analysis of clinical experiments. New York: Wiley; 1986. 33. Hoddinott SN, Bass MJ. The dillman total design survey method. Can Fam Physician 1986;32:2366–2368. 34. Nunnally JC. Psyochometric theory. New York: McGraw-Hill; 1978. 35. Public Health Agency of Canada. Life and breath: respiratory diseases in Canada. Ottawa, Canada: Public Health Agency of Canada;2007:129p. 36. Kolbe J. Asthma education, action plans, psychosocial issues and adherence. Can Respir J 1999;6:273–280. 37. Yoon R, McKenzie DK, Miles DA, Bauman A. Characteristics of attenders and non-attenders at an asthma education programme. Thorax 1991;46:886–890. 38. Malo JL, Ghezzo H, L’Archeveˆque J, Lagier F, Perrin B, Cartier A. Is the clinical history a satisfactory means of diagnosing occupational asthma? Am Rev Respir Dis 1991;143:528–532.
J Asthma, 2015; 52(3): 279–288
39. Coˆte´ J, Kennedy S, Chan-Yeung M. Sensitivity and specificity of PC20 and peak expiratory flow rate in cedar asthma. J Allergy Clin Immunol 1990;85:592–598. 40. Baur X, Huber H, Degens PO, Allmers H, Ammon J. Relation between occupational asthma case history, bronchial methacholine challenge, and specific challenge test in patients with suspected occupational asthma. Am J Ind Med 1998;33:114–122. 41. Vandenplas O, Binard-Van Cangh F, Brumagne A, Caroyer JM, Thimpont J, Sohy C, Larbanois A, et al. Occupational asthma in symptomatic workers exposed to natural rubber latex: evaluation of diagnostic procedures. J Allergy Clin Immunol 2001;107:542–547. 42. Pralong JA, Moullec G, Suarthana E, Ge´rin M, Gautrin D, Archeveˆque JL, Labrecque M. Screening for occupational asthma by using a self-administered questionnaire in a clinical setting. J Occup Environ Med 2013;55:527–531. 43. Vandenplas O, Ghezzo H, Munoz X, Moscato G, Perfetti L, Lemie`re C, Labrecque M, et al. What are the questionnaire items most useful in identifying subjects with occupational asthma? Eur Respir J 2005;26:1056–1063.
ISSN: 0277-0903 (Print) 1532-4303 (Online) Journal homepage: http://www.tandfonline.com/loi/ijas20
The development and test re-test reliability of a work-related asthma screening questionnaire Katie R. Killorn MSc, Suzanne M. Dostaler MSc, Jennifer Olajos-Clow MSc, Scott E. Turcotte MSc, Janice P. Minard MSc, D. Linn Holness MHSc, MD, Irena Kudla MHSc, CIH, Catherine Lemière MD, MSc, Teresa To PhD, Gary Liss MD, MS, Susan M. Tarlo MBBS & M. Diane Lougheed MD, MSc To cite this article: Katie R. Killorn MSc, Suzanne M. Dostaler MSc, Jennifer Olajos-Clow MSc, Scott E. Turcotte MSc, Janice P. Minard MSc, D. Linn Holness MHSc, MD, Irena Kudla MHSc, CIH, Catherine Lemière MD, MSc, Teresa To PhD, Gary Liss MD, MS, Susan M. Tarlo MBBS & M. Diane Lougheed MD, MSc (2015) The development and test re-test reliability of a work-related asthma screening questionnaire, Journal of Asthma, 52:3, 279-288 To link to this article: http://dx.doi.org/10.3109/02770903.2014.956892
Accepted online: 02 Sep 2014.Published online: 09 Sep 2014.
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http://informahealthcare.com/jas ISSN: 0277-0903 (print), 1532-4303 (electronic) J Asthma, 2015; 52(3): 279–288 ! 2014 Informa Healthcare USA, Inc. DOI: 10.3109/02770903.2014.956892
OCCUPATIONAL ASTHMA
The development and test re-test reliability of a work-related asthma screening questionnaire Katie R. Killorn, MSc1,2, Suzanne M. Dostaler, MSc1,2, Jennifer Olajos-Clow, MSc1,2, Scott E. Turcotte, MSc1,2, Janice P. Minard, MSc1,2, D. Linn Holness, MHSc, MD3,4,5,6, Irena Kudla, MHSc, CIH3,5,6, Catherine Lemie`re, MD, MSc7, Teresa To, PhD3,8, Gary Liss, MD, MS3,6, Susan M. Tarlo, MBBS3,4,5,6,9, and M. Diane Lougheed, MD, MSc1,2,6
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1
Asthma Research Unit, Kingston General Hospital, Kingston, Ontario, Canada, 2Division of Respirology, Department of Medicine, Queen’s University, Kingston, Ontario, Canada, 3Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada, 4Department of Medicine, University of Toronto, Toronto, Ontario, Canada, 5Department of Occupational and Environmental Health, St. Michael’s Hospital, Toronto, Ontario, Canada, 6The Center for Research Expertise in Occupational Disease, Toronto, Ontario, Canada, 7Service de Pneumologie, Hoˆpital du Sacre´ Coeur, Universite´ de Montre´al, Montre´al, Que´bec, Canada, 8Child Health Evaluative Sciences, The Hospital for Sick Children, Toronto, Ontario, Canada, and 9Respiratory Division, University Health Network, Toronto, Ontario, Canada
Abstract
Keywords
Objective: Work-related asthma (WRA) is under-recognized and delays in recognition contribute to long-term morbidity. The objective of the project was to develop a WRA screening questionnaire for use by primary care providers in the assessment of individuals with asthma, and to evaluate the respondent burden, test re-test reliability and face validity of the questionnaire. Methods: A literature search was undertaken and an expert advisory committee was convened. A questionnaire was drafted and assessed for feasibility of use and content validity. The study enrolled patients with asthma attending outpatient clinics and an asthma education center. Participants were asked to respond to the questionnaire on two occasions, and comment on the content (face validity) and ease of completion (respondent burden). Ethics approval was obtained from an institutional review board. Results: A 14-item selfadministered screening questionnaire was created. Thirty-nine participants were recruited, and 26 participants completed a second administration of the questionnaire. The items on the relation of asthma symptoms to work demonstrated substantial agreement between testings. The workplace exposures items were found to have good reproducibility. The majority of participants denied that items were repetitive, not useful or difficult to understand. Conclusions: We have developed a WRA screening questionnaire designed to aid primary care providers in the recognition of possible WRA. The tool exhibited content and face validity, good test re-test reliability and low respondent burden. Participant feedback is being considered in revisions of the questionnaire.
Occupational asthma, prevention, primary care, questionnaire, work-aggravated asthma, work-exacerbated asthma
Introduction Environmental factors play an important role in the origin and persistence of asthma [1]. As much as 25% of adults with asthma are estimated to have work-related asthma (WRA) [2]. WRA encompasses two subtypes of occupational respiratory diseases: occupational asthma (OA), which includes asthma induced by sensitizer or irritant work exposures; and work-exacerbated asthma (WEA), whereby pre-existing or concurrent asthma is worsened by work factors [2]. WRA is associated with poor health outcomes. Continued exposure to a causative agent in the workplace can lead to progressive deterioration of lung function, in Correspondence: Dr. M. Diane Lougheed, Division of Respirology, Department of Medicine, Queen’s University, 102 Stuart Street, Kingston, Ontario, Canada K7L 2V6. Tel: 613.548.2348. Fax: 613.547.1459. E-mail: [email protected]
History Received 28 March 2014 Revised 15 August 2014 Accepted 16 August 2014 Published online 9 September 2014
terms of forced expiratory volume in one second, non-specific hyper-responsiveness and symptoms [3]. However, many workers are left with permanent lung impairment despite removal from the offending agent [4]. It has been determined that early diagnosis and early avoidance of further exposure increase the likelihood of full recovery [5]. Delays in recognition contribute to long-term morbidity [6–9]. This literature is largely based on studies of patients with OA. Similar findings of improvement after cessation have been found for patients with WEA, but to a lesser extent [10,11]. Adults with asthma are primarily cared for by their family physicians [12]. Family physicians and respirologists report lack of knowledge, time and expertise as main barriers to early recognition of WRA [13,14]. Questionnaires have been identified as a means of identifying individuals with WRA [13,15]. To our knowledge, a screening questionnaire to
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aid in the identification of individuals with possible WEA and/or OA, designed specifically for use in the primary care setting does not exist. In 2002, the Government of Ontario funded a provincial ‘‘Asthma Plan of Action’’ in an effort to increase the implementation of the Canadian Thoracic Society’s Asthma Guidelines [16]. One of the initiatives that developed from this action plan was the Primary Care Asthma Program (PCAP), an evidence- [16] and outcomes- [17] based asthma care program implemented in 12 primary care sites with multiple locations across Ontario. Tools such as the Ontario Lung Association Asthma Care Map (ACM) are used within PCAP sites. The ACM is a template for asthma management that includes seven WRA screening questions. The first objective of this study was to develop a selfadministered WRA screening questionnaire for use by primary care providers in the assessment of individuals with confirmed asthma. For PCAP sites, this questionnaire would be used as a means of prompting a more detailed occupational history of patients answering affirmatively to one of the WRA screening items on the ACM. A stand-alone version of the questionnaire would be created for non-PCAP primary care sites not using the ACM already. The second objective was to examine the respondent burden, face validity, and test re-test reliability of the screening questionnaire.
Methods Literature search and development The American College of Chest Physicians Consensus Statement on WRA [2] was consulted and a search of databases and websites was undertaken (Table 1). The objective of this search was to compile existing WRA instruments and items, published studies assessing the validity and reliability of these instruments and items, and a comprehensive list of offending inhalation exposures, as resources in the development of the screening questionnaire. An Advisory Committee (AC) consisting of nine members including respiratory medicine providers, occupational lung disease experts, primary care practitioners and epidemiologists was convened to provide expert feedback throughout the development process. Instruments containing items relating to occupation and exposure were compiled. Further, a list of potential offending agents provided by the expert panel was supplemented and categorized. A questionnaire was drafted Table 1. Literature and internet search terms. Search terms Question* AND occupation* asthma Work AND asthma Exposure AND asthma
Work-related asthma question* Work-related asthma
and assessed for content validity (whether the questionnaire adequately samples the intended domain of content, often assessed through expert review [18]), as well as feasibility of use by the AC members. Study design and population A study was conducted to assess the test-retest reliability, face validity and respondent burden of the questionnaire. This study aimed to enroll at least 30 patients with asthma attending specialist outpatient clinics (respirology) and an asthma education center. This asthma education center received patients referred from both primary care providers and specialists. Patients were eligible if they were Englishspeaking, of working age (18–65 years) and had a diagnosis of asthma (doctor diagnosis, confirmed with objective measures [16]). Further, they had to be able to give consent, and be available to respond to a mailed second questionnaire 1 month after recruitment. The clinical care provider identified eligible patients from the clinic attendance lists. The research associate introduced the study and gathered written informed consent if the patient was interested in participating. Participants were asked to respond to the questionnaire (paper-version) on two occasions. Participants completed the first questionnaire unaided in clinic. Two to four weeks later, they received and returned their second questionnaire by mail. If questionnaires were not returned within a 3-week delay, a single reminder telephone contact was attempted. In addition to the WRA screening questionnaires, participants were given a separate paper survey to complete on both occasions. This survey collected demographic information (gender, age, education level, age at which a doctor first told them they had asthma). Face validity is the appropriateness, sensibility, or relevance of a test and its’ items to the responder of that test [19]. In order to assess this, participants were asked to comment on the content of the WRA screening questionnaire (whether questions were ‘‘repetitive or not useful’’) and to suggest other questions for inclusion. Respondent burden was assessed by asking participants to comment on the ease of use (whether questions were ‘‘difficult to understand’’) and for the time it took to complete. Last, participants were asked to self-report whether their asthma was caused or aggravated by their work. Ethics approval for the study was obtained from the Queen’s University Health Sciences and Affiliated Teaching Hospitals Research Ethics Board. Statistical analysis
Database/search engine Cochrane Library Health and Psychological Instruments ISI Web of Science Medline (Ovid, PubMed) (Lim: 1975, adult) Google Scholar NIOSH
NIOSH, National Institute for Occupational Safety and Health. *Truncation symbol, retrieves all terms that begin with a given text string.
Univariate analyses were conducted to describe study sample characteristics, as well as screening questionnaire and survey responses. As part of the test re-test reliability analyses, the characteristics of those who completed two questionnaires were compared to those participants who completed one questionnaire (lost to follow-up). The two-sample t test for independent samples was used to test differences between samples on continuous participant characteristic variables, once normality of variables was established using the Shapiro–Wilk test. The Pearson’s chi-square test with Yates correction for continuity was used to test
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differences between samples on discrete participant characteristic variables. For contingency tables with expected cell counts of less than five, Fisher’s exact test was applied for the computation of p values. Cohen’s Kappa was computed to assess the test re-test reliability of questionnaire items with dichotomous outcomes (Y/N). Multiple choice exposure items were converted into continuous variables (scores) by separately summing the number of past and current exposure items. These items were assessed for test re-test reliability by computing the intra-class correlation coefficient (ICC) (1, 1). For all Kappa and ICC statistics, 95% confidence intervals were computed and tests of significance were conducted against a level of agreement or reliability of zero. A significance level (a) of 0.05 was chosen for all analyses. Statistical procedures were conducted using IBMÕ SPSSÕ for Windows (Version 20.0, Armonk, NY).
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Results Literature and Internet search findings Table 2 presents the 10 instruments containing occupation and/ or exposure items that were assembled from the literature and internet search. Two of the 10 tools were designed for clinical purposes. The first was a general work health screening tool used in an occupational health clinic at St. Michael’s Hospital, Toronto [20] and the second was a list of assessment questions for care providers to use in the assessment of asthma that is made worse at work created by the National Heart, Lung, and Blood Institute of the National Institutes of Health [21]. Neither had been assessed for validity. Two of the tools found in the search were specific to WRA surveillance programs. One was used as a means of characterizing and classifying WRA cases reported in a surveillance system in Washington State [22] and the other was used for physician reporting of WRA cases as part of the Ontario WRA Surveillance project [23]. Further, two instruments of the search were designed specifically for etiological research in occupational
populations. The first was an extensive questionnaire designed for research on asthma in healthcare workers that was developed by researchers at the University of Texas Health Science Center at Houston. It was formally tested for validity and reliability [24], although items related to time of asthma onset, worsening of asthma symptoms with work and amelioration of asthma symptoms when away from work were not specifically validated. The second tool was an occupational questionnaire from the National Institute for Occupational Safety and Health that has been used to assess the occurrence of asthma among at-risk occupational groups and contains an extensive number of items on symptoms and exposures [25]. The rest of the instruments were standard respiratory health questionnaires used for epidemiological research purposes that included work-related items [26–29]. To our knowledge, these have not been validated to predict WRA or to distinguish between non-WRA and WRA. The selected instruments provided over 70 items exhibiting considerable overlap. The items were categorized to reflect seven concepts: asthma diagnosis, education, workplace exposures (agents, duration, frequency, level), occupation history, relation of asthma symptoms to occupation, symptomatic co-workers, and seasonal variation in asthma symptoms. A list of 21 categories of known offending exposure agents was compiled. Questionnaire After an iterative editing process, two versions of the WRA screening questionnaire were prepared. The first was a one-page tool designed to supplement the seven WRA screening questions in the ACM in use at PCAP sites, titled the WRA Screening Questionnaire (short-version). The second was the full screening questionnaire, titled the WRA Screening Questionnaire (Long-version) [WRASQ(L]) (Figure 1), which included the WRA screening questions from the ACM and consequently, was intended for use in primary care sites not employing the ACM.
Table 2. Ten resulting instruments from the literature and internet search.
1 2 3 4 5 6 7 8 9 10
Instrument
Source
Current Work/Health/Exposure Tool Expert Panel Report 3: Guidelines for the Diagnosis and Management of Asthma Work-related Asthma Follow-Up Worker Questionnaire OWRAS Chart Abstraction Form A Survey of Asthma in Health Professionals
St. Michael’s Hospital, Toronto, Canada. [20] NHLBI of the NIH, USA. [21]
Initial Questionnaire of the NIOSH Occupational Asthma Identification Project ATS-DLD-78 Respiratory Questionnaire European Community Respiratory Health Survey Questionnaire for the Epidemiological Study on the Genetics and Environment of Asthma, Bonchial Hyper-responsiveness and Atopy St. George’s Respiratory Questionnaire
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Washington State Labor and Industries, USA. [22] To et al., University of Toronto, Canada. [23] Delclos et al., University of Texas Health Science Center at Houston, USA. [24] Division of Respiratory Disease Studies, NIOSH, USA. [25] ATS and the DLD of the NHLBI (NIH), USA. [26] Burney et al., United Medical and Dental Schools of Guy’s and St Thomas’ Hospitals, London, UK. [27] Kauffman et al., Institut National de la Sante´ et de la Recherche Me´dicale, France. [28] Jones et al., St. George’s University of London, UK. [29]
NHLBI, National Heart, Lung and Blood Institute; NIH, National Institutes of Health; OWRAS, Ontario Work-related Asthma Surveillance; NIOSH, National Institute for Occupational Safety and Health; ATS, American Thoracic Society; DLD, Division of Lung Diseases.
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This 14-item questionnaire spanned one and a half pages and was based on three concepts: job type and employment duration (three items), relationship of symptoms (eight items), as well as exposures and exposure avoidance (three items). The items also present on the ACM were items 1, 4 to 6, 11 and 12, although, the occupation (item 1) and exposure (item 12) items had different response formats than the WRASQ(L) and item 11 was split into two separate questions on the ACM. The WRASQ(L) was used in the current study, and consequently, the remainder of this report will refer to this longversion.
Figure 1. The work-related asthma screening questionnaire (long-version).
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Sample characteristics Thirty-nine participants were recruited in this study. Characteristics of this sample are presented in Table 3. When participants were asked if their asthma was caused or aggravated by their work environment on the additional survey, 41.7% responded ‘‘yes’’. Current occupations encompassed all major industry types under the Statistics Canada National Occupational Classification for Statistics (NOC-S 2006) [30], except the ‘‘primary industry’’ category.
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Figure 1. Continued.
Test re-test reliability All 39 study participants completed the WRASQ(L) once. A total of 26 of the 39 participants completed the WRASQ(L) a second time, and the remaining 13 participants were lost to follow-up. Table 4 compares the participants who completed the WRASQ(L) once (n ¼ 13) to those who completed it twice (n ¼ 26). Although the test re-test sample was slightly older, comprised of more females and had a smaller percentage of participants reporting asthma that is caused or aggravated by the workplace, there were no statistically significant (p50.05) differences between groups. The number of days between the first and second
administrations of the questionnaire ranged from 16 to 63 d, with a mean of 33.7 d (SD, 13.4). There were two changes in employment (occupation type, and/or status) between the first and second administration of the WRASQ(L). Table 5 presents the results of the test re-test reliability analysis for items 4 to 14 of the WRASQ(L). Missing values were considered as non-affirmative responses in this analysis. Of those items assessed for agreement using Cohen’s Kappa statistic, the majority ranged from 0.42 to 0.77, while the lowest value was 0.28 for item 14 (use of protective measures). Concerning reproducibility, the ICC value for the count of workplace exposures was 0.74 for current, and 0.78 for past.
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Table 3. Study sample characteristics. N ¼ 39
n
Mean, SD
Median (Range)
Age Age at diagnosis Years at current job
39 39 35
47.3, 12.3 30.7, 18.3 12.3, 11.4
48 (19–68) 32 (1–64) 7 (0.5–42)
N ¼ 39
n
Categories
%a
Gender
39
Education
38
Employment
39
Asthma aggravated or caused by workb
36
Female Male Less than or some high school High school graduate Technical training Some college or university College or university graduate Post-graduate study Full-time Part-time Retired Off work Other Yes No Unknown
53.8 46.2 10.5 18.4 2.6 18.4 39.5 10.5 51.3 17.9 12.8 12.8 5.1 41.7 25.0 33.3
a
Totals may not add up to 100% due to rounding error. ‘‘Asthma aggravated or caused by work’’ was self-reported in response to an item on the participant survey (separate from the Work-related Asthma Screening Questionnaire [Long-version]).
b
Table 4. A comparison of participants who completed one WRASQ(L) and participants who completed two WRASQ(L)s. Completed 1 WRASQ(L) (n ¼ 13)
Completed 2 WRASQ(L)s (n ¼ 26)
Characteristic
n
Mean, SD
Median (Range)
n
Mean, SD
Median (Range)
p Valuea
Age (years) Age at diagnosis
13 13
44.9, 14.1 29.4, 17.9
47 (19–68) 32 (1–64)
26 26
48.6, 11.4 31.4, 18.8
48.5 (23–64) 31.5 (1–60)
0.380 0.757
Characteristic
N
%
N
%
p Valueb
Female Asthma aggravated or caused by workc some college or universityd
13 13 12
26 23 26
61.5 39.1 69.2
0.307 0.953 1.000
38.5 46.2 66.7
a
Two-sample t test for independent samples. Pearson chi-square test, with yates correction for continuity. ‘‘Asthma aggravated or caused by work’’ was self-reported in response to an item on the participant survey (separate from the Work-related Asthma Screening Questionnaire [Long-version]). d Fisher’s exact test. b c
Face validity and respondent burden These results are based on combined participant responses from both the first (N ¼ 39) and second (n ¼ 26) feedback surveys, with repetitive answers from the same participant removed. In terms of face validity, six participants listed items as ‘‘repetitive’’ or ‘‘not useful’’. None of these comments were relevant for revision (e.g. ‘‘not applicable to my employment’’). As general comments, two participants listed they were retired and two participants reported they worked from home, with the common concern that this questionnaire might not apply to them. Twenty-one participants suggested additional topics for inclusion on the WRASQ(L). While applicable to asthma care, the majority of these suggestions did not align with the purposes of a
succinct screening questionnaire for WRA in primary care, as determined by expert (author) review. Of note, participants suggested the tool include the following exposures: ‘‘stress’’ (n ¼ 5), ‘‘perfumes’’ (n ¼ 2), and ‘‘physical labor’’ (n ¼ 1). Two participants suggested the inclusion of an item inquiring about the triggers or causal factors related to their asthma. In terms of respondent burden, 10 participants stated they did not know what isocyanates were. Five participants listed other items/concepts as ‘‘difficult to understand’’, and only comment was relevant for a revision. This participant suggested that item 14 specify whether protective measures are used currently, or in the past. The first administration required on average 7.2 min (n, 32 (missing 7); SD, 3.8; range, 2–20), and the second administration required on average 6.5 min (n, 26; SD, 3.6; range, 2–15).
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285
Table 5. Test re-test reliability of items 4–14 on the WRASQ(L). (n ¼ 26)
Time 2
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Items 4
Did your asthma symptoms start at work?
5
Did your asthma symptoms start in days of a spill or fire at work?
6
Did your asthma symptoms worsen at work?
7
Do your asthma symptoms worsen on first day back to work?
8
Do your asthma symptoms worsen during the work day?
9
Do your asthma symptoms worsen at home after work?
10
Do your asthma symptoms worsen throughout work week?
11
Are chest symptoms different (less) on days off work and/or holidays?
14
Are protective measures used?
Time 1
N
Y
N Y N Y N Y N Y N Y N Y N Y N Y N Y
20 1 26 0 12 3 18 3 12 4 19 1 13 4 13 3 11 4
1 4 0 0 0 11 1 4 1 9 3 3 3 6 0 10 5 6
Kappa (95% CI)
p Valuea
0.75 (0.43, 1.08)
50.001
n/a
n/a
0.77 (0.53,1.01)
50.001
0.57 (0.20, 0.94)
0.003
0.62 (0.32, 0.91)
0.001
0.51 (0.10, 0.92)
0.007
0.42 (0.06, 0.78)
0.031
0.77 (0.53, 1.01)
50.001
0.28 (0.09, 0.65)
0.149
Mean ± SD
12 13
Number of current exposures Number of past exposures
Time 1
Time 2
5.5 ± 4.4 7.3 ± 4.7
5.8 ± 4.8 7.7 ± 4.9
ICC (95% CI) 0.74 (0.51–0.87) 0.78 (0.58–0.90)
p Valuea 50.001 50.001
a
Tested against a minimum level of agreement or correlation of 0. ICC, intra-class correlation coefficient.
Discussion Main findings We developed a WRA screening questionnaire with content and face validity, good test re-test reliability and low respondent burden. A striking 40% of participants (albeit a select group) self-reported that their asthma was caused or aggravated by the work environment. Although we cannot generalize from their experience, this may provide rationale for potential benefit of implementing evidence-based tools that prompt and enable clinical care providers to assess for possible WRA. In terms of test re-test reliability, characteristics of participants who were lost to follow-up did not differ significantly (p50.05) from those who completed the second WRASQ(L). Questionnaire items on the relation of asthma symptoms to work were found to have ‘‘moderate’’ to ‘‘substantial’’ agreement [31]. Of those items, the ‘‘start at work’’, ‘‘worsen at work’’, and ‘‘different (less) on days off work and/or holidays’’ items demonstrated the highest agreement between testings. The item inquiring about the use of protective measures in the workplace demonstrated the lowest stability (‘‘fair agreement’’ [31]) and the reason for this is unknown. The current and past workplace exposure items demonstrated ‘‘good’’ and ‘‘excellent’’ reproducibility [32], respectively. Overall, the majority of participants denied that items were repetitive, not useful or difficult to understand. This tool demonstrated low respondent burden and good face validity. The comments and suggestions made by participants were addressed in the following ways. First, there was marked confusion over the term ‘‘isocyanates’’. Those truly
exposed to this material are likely to be familiar with this term, due to strict regulations on the use of this material in the workplace. However, to address this concern, future implementation plans will include access to explanations for potentially confusing terms such as isocyanates, and the difference between a mask and respirator. Patients would be permitted to ask a health care professional for clarification. Additionally, we propose to add ‘‘help’’ icons beside terms on the electronic version of the WRASQ(L) that has been developed since this study was completed. Second, a revision to item 14 (use of protective equipment) will be made to clarify the time frame (present versus past). Third, it will be specified in item three that ‘‘employment status’’ includes those who are self-employed or working from home, and a separate ‘‘retired’’ response category will also be created. For those selecting ‘‘retired’’ or ‘‘off work due to respiratory health’’, the tense of ensuing questionnaire items will automatically be adjusted from current to past on the electronic WRASQ(L). Finally, the addition of exposures (‘‘exercise’’, ‘‘perfumes/scents’’, and ‘‘stress’’), and an item related to known causal or exacerbating work exposures, are being considered in revisions of the WRASQ(L). Although ‘‘stress’’ is a recognized trigger of asthma, it is not considered to be an occupational agent and the degree to which it triggers asthma is somewhat controversial. Strengths and limitations As mentioned previously, we are not aware of another screening questionnaire for both WEA and OA, designed specifically for use in the primary care setting. By prompting a detailed history of employment and exposures, this
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questionnaire may lead to improved recognition of WRA in primary care. A limitation of this study is the low number of participants that completed a second administration of the WRASQ(L). This resulted in wide confidence intervals around the test re-test reliability estimates, including negative lower limits. The well-cited Dillman survey method states that nonresponders should be followed-up 1 week after the initial mail-out with a reminder postcard, and 3 and 7 weeks after the initial mail-out with replacement questionnaires [33]. In this study, a single reminder phone call was attempted 1 week after initial mail-out, which may have affected response rates. Other limitations of the study relate to potential sources of measurement error in the test re-test reliability estimates. First, the number of days between administrations of questionnaire ranged from 16 to 63 d (mean, 33.7), while the recommended amount of time between testings is 2 weeks to 1 month [34]. Test re-test reliability estimates may have been underestimated due to slightly prolonged time between administrations. Second, a change in employment status or occupation between the two administrations of the tool may have inappropriately underestimated the test re-test reliability estimates since true changes may have occurred. However, only two participants reported a change in occupation and/or employment status between testings. Third, estimates of test re-test reliability may have been affected by the different locations of each questionnaire administration (clinic versus home). While it is important to acknowledge these potential sources of measurement error, the test re-test reliability of the WRASQ(L) is acceptable.
occupational lung disease clinic for suspected OA [42]. Specific questions addressed by physicians in the assessment of OA have also been validated in workers referred to specialist care settings for suspected OA. In fact, four of the eight symptom items on the WRASQ(L) have been tested in such studies. The sensitivity and specificity of such items are presented here based on calculations from the publications. A version of the ‘‘worsen throughout the work week’’ item was found to have a sensitivity of 15% and a specificity of 84% [43], while iterations of the ‘‘worsen at home after work’’ item have been found to have a sensitivity of 69% and a specificity of 27 to 46% [38,43]. The items with the highest sensitivity are versions of the ‘‘worsen at work’’ (sensitivity, 90–91%; specificity, 9–14%) [38,43] and ‘‘different (less) on days off work/holidays’’ (sensitivity, 74–88%; specificity, 24–57%) [38,43] items. The symptom items on the WRASQ(L), as well as combinations of these items, need to be evaluated in a formal validation study of the diagnosis of both OA and WEA in unselected asthma patients in a primary care setting.
Interpretation of findings in relation to relevant studies
Conclusions
The study sample was predominantly female and middleaged, which is characteristic of adult asthma in Canada [35]. Interestingly, a substantial percentage of participants in this sample were highly educated. Although this demographic distribution is comparable with reports of attendees of outpatient asthma education programs [36,37], these results may not be generalizable to other adult asthma populations. Specifically, the education level of the sample may have affected the results related to respondent burden and face validity. A larger group of less educated workers should be studied. Given the recruitment setting, the majority of participants in this study were followed by respirologists. Clinical history (judgment) of respirologists and occupational medicine specialists has been found to be highly sensitive in the diagnosis of OA [38–41]. However, there may be ample opportunity to increase the sensitivity of clinical judgment in relation to WRA diagnosis in primary care. Subsequent studies assessing the WRASQ(L) will take place within its intended primary care setting. Since this study was completed, Pralong et al. reported on a self-administered, 11-item, OA-specific Screening Questionnaire (OASQ-11). A model of eight of the questionnaire items, along with age and exposure duration, was able to correctly classify 80% of workers referred to a tertiary care
Implications for future research and practice The use of an electronic version of the WRASQ(L) is currently being evaluated in a primary care asthma program. Criterion validity and effectiveness of this as a tool to alert physicians to possible WRA will need to be assessed in a prospective study. Once validated and incorporated into standard practice, this questionnaire is expected to increase recognition of WRA, prompt adherence with evidence-based guidelines for the management of WRA, and facilitate timely, accurate adjudication of compensation claims.
We have developed a 14-item, self-administered screening questionnaire [WRASQ(L]) designed to increase the recognition of possible WEA and OA in the primary care setting. The WRASQ(L) exhibited content and face validity, good test re-test reliability and low respondent burden. Future directions include revision of this tool based upon these findings and findings from a pilot implementation in primary care currently underway, and a prospective validation of this tool with respect to both WEA and OA.
Acknowledgements We would like to acknowledge Dr. Patti Groome for contribution to these statistical methods. We would also like to acknowledge Dr. Peter Bell for his feedback in the development of the WRASQ(L) as well as research assistant Kendra Barrick, for her assistance in the assembly of instruments in the literature search.
Declaration of interest The authors alone are responsible for the content and writing of the article. The test re-test reliability analysis in this article is based on statistical methodology developed by K.R.K. as part of an academic thesis in the Department of Public Health Sciences at Queen’s University, Kingston, Ontario (supervisors: M.D.L., Dr. Patti Groome).
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DOI: 10.3109/02770903.2014.956892
K.R.K., S.M.D., S.E.T., J.P.M., C.L., and T.T. report no conflicts of interest. J.O.C. has received an honorarium from Takeda Canada for conducting a workshop on inhalation devices for asthma medication to primary care practitioners. D.L.H. has received peer-reviewed research funding from the Ontario Ministry of Labor, the Ontario Workplace Safety and Insurance Board (WSIB), and the Social Sciences and Humanities Research Council. I.K. has received peerreviewed research funding from the Ontario Ministry of Labor and the Ontario WSIB. G.L. has received research funding as an investigator from the Ontario WSIB Research Advisory Council, which supported research assistants and data analyses, but no funding went to the investigators. S.M.T. has received previous funding for research studies on WRA from the Ontario WSIB, the Worker’s Compensation Board (WCB) of Manitoba, and WorkSafe BC, and has performed clinical consultations of patients at the request of the Ontario WSIB. M.D.L. has received research funding from the Government of Ontario, the Ontario Lung Association, MPEX Pharmaceuticals, Pharmaxis Ltd., AllerGen NCE Inc. (the Allergy, Genes and Environment Network), the Ontario Thoracic Society, the Canadian Cystic Fibrosis Foundation, Queen’s University, Glaxo Smith Kline Inc., Janssen Inc., and speaker honoraria from the Ontario Lung Association. G.L., C.L., T.T. and S.M.T. were co-investigators with MDL on the WRA and Allergy Prevention and Early Detection (WRAAPED) Research Program team grant, supported by AllerGen NCE Inc. The work completed for this specific project was funded by both AllerGen NCE Inc. (grant number #07C4) and the Ontario WSIB.
11.
12.
13. 14. 15. 16.
17.
18. 19. 20.
21.
References 1. Busse WW, Lemanske Jr RF,. Asthma. New Engl J Med 2001;344: 350–362. 2. Tarlo SM, Balmes J, Balkissoon R, Beach J, Beckett W, Bernstein D, Blanc PD, et al. Diagnosis and management of work-related asthma: American College of Chest Physicians Consensus Statement. Chest 2008;134:1S–41S. 3. Beach J, Rowe BH, Blitz S, Crumley E, Hooton N, Russell K, Spooner C, et al. Diagnosis and management of work-related asthma: summary. Rockville (MD): Agency for Healthcare Research and Quality (US); 2005 Report No.: Report No.: 06E003-1. 4. Rachiotis G, Savani R, Brant A, MacNeill SJ, Newman Taylor A, Cullinan P. Outcome of occupational asthma after cessation of exposure: a systematic review. Thorax 2007;62:147–152. 5. Nicholson PJ, Cullinan P, Taylor AJN, Burge PS, Boyle C. Evidence based guidelines for the prevention, identification, and management of occupational asthma. Occup Environ Med 2005;62: 290–299. 6. Chan-Yeung M, MacLean L, Paggiaro PL. Follow-up study of 232 patients with occupational asthma caused by western red cedar (Thuja plicata). J Allergy Clin Immunol 1987;79:792–796. 7. Rosenberg N, Garnier R, Rousselin X, Mertz R, Gervais P. Clinical and socio-professional fate of isocyanate-induced asthma. Clin Allerg 1987;17:55–61. 8. Tarlo SM, Banks D, Liss G, Broder I. Outcome determinants for isocyanate induced occupational asthma among compensation claimants. Occup Environ Med 1997;54:756–761. 9. Wheeler S, Rosenstock L, Barnhart S. A case series of 71 patients referred to a hospital-based occupational and environmental medicine clinic for occupational asthma. West J Med 1998;168: 98–104. 10. Pelissier S, Chaboillez S, Te´olis L, Lemiere C. Outcome of subjects diagnosed with occupational asthma and work-aggravated
22.
23.
24. 25.
26. 27. 28.
29. 30.
287
asthma after removal from exposure. J Occup Environ Med 2006; 48:656–659. Lemiere C, Forget A, Dufour MH, Boulet LP, Blais L. Characteristics and medical resource use of asthmatic subjects with and without work-related asthma. J Allergy Clin Immunol 2007;120:1354–1359. To T, Gershon A, Tassoudji M, Guan J, Chengning W, Estrabillo E, Cicutto L. The burden of asthma in Ontario. ICES investigative report. Toronto (ON): Institute for Clinical Evaluative Sciences (CA); 2006 Sept. 44 p. Holness DL, Tabassum S, Tarlo SM, Liss GM, Silverman F, Manno M. Practice patterns of pulmonologists and family physicians for occupational asthma. Chest 2007;132:1526–1531. Parhar A, Lemiere C, Beach JR. Barriers to the recognition and reporting of occupational asthma by Canadian pulmonologists. Can Respir J 2011;18:90–96. Walters GI, McGrath EE, Ayres JG. Audit of the recording of occupational asthma in primary care. Occup Med (Lond) 2012;62: 570–573. Lougheed MD, Lemie`re C, Dell SD, Ducharme FM, Fitzgerald JM, Leigh R, Licskai C, et al. Canadian Thoracic Society Asthma Management Continuum – 2010 Consensus Summary for children six years of age and over, and adults. Can Respir J 2010;17:15–24. To T, Cicutto L, Degani N, McLimont S, Beyene J. Can a community evidence-based asthma care program improve clinical outcomes?: a longitudinal study. Med Care 2008;46: 1257–1266. Coolidge FL, Segal DL. Validity. The Corsini Encyclopedia of Psychology: John Wiley & Sons, Inc.; 2010:1–2. Holden RR. Face validity. The Corsini Encyclopedia of Psychology: John Wiley & Sons, Inc.; 2010:1–2. Department of Occupational and Environmental Health, St-Michael’s Hospital. Work/health exposure screening tool. St-Michael’s Hospital. Available from: http://www.stmichaelshospital.com/programs/occupationalhealth/resources.php [last accessed 25 Jun 2009]. National Asthma Education and Prevention Program, Third Expert Panel on the Diagnosis and Management of Asthma. Expert Panel Report 3: guidelines for the diagnosis and management of asthma. Bethesda (MD): National Heart, Lung and Blood Institute (US); 2007 Aug. 417 p. Report No.: 07-4051. Anderson NJ, Reeb-Whitaker CK, Bonauto DK. Work-related asthma in Washington state: a summary of SHARP’s asthma surveillance data from 2001-2009. Olympia (WA): Safety and Health Assessment and Research for Prevention (SHARP) Program, Washington State Department of Labor and Industries (US); 2010 Report No.: 64-13-2010. To T, Tarlo SM, McLimont S, Haines T, Holness DL, Lougheed MD, Liss GM, et al. Feasibility of a provincial voluntary reporting system for work-related asthma in Ontario. Can Respir J 2011;18:275–277. Delclos GL, Arif AA, Aday L, Carson A, Lai D, Lusk C, Stock T, et al. Validation of an asthma questionnaire for use in healthcare workers. Occup Environ Med 2006;63:173–179. NIOSH Division of Respiratory Disease Studies. Initial Questionnaire of the NIOSH Occupational Asthma Identification Project. Centers for Disease Control and Prevention. Available from: http://www.cdc.gov/niosh/asthwww.txt [last accessed 25 Jun 2009]. Ferris BG. Epidemiology standardization project (American Thoracic Society). Am Rev Respir Dis 1978;118:1–120. Burney PG, Luczynska C, Chinn S, Jarvis D. The European Community Respiratory Health Survey. Eur Respir J 1994;7: 954–960. Kauffmann F, Annesi-Maesano I, Liard R, Paty E, Faraldo B, Neukirch F, Dizier MH. [Construction and validation of a respiratory epidemiological questionnaire]. Rev Mal Respir 2002; 19:323–333. Jones PW, Quirk FH, Baveystock CM. The St George’s Respiratory Questionnaire. Respir Med 1991;85:25–31. Statistics Canada. National Occupational Classification–statistics (NOC-S) 2006 statistics Canada. Available from: http://www. statcan.gc.ca/subjects-sujets/standard-norme/soc-cnp/2006/ noc2006-cnp2006-menu-eng.htm [last accessed 25 Jun 2009].
288
K. R. Killorn et al.
Downloaded by [ECU Libraries] at 12:53 22 September 2015
31. Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics 1977;33:159–174. 32. Fleiss JL. The design and analysis of clinical experiments. New York: Wiley; 1986. 33. Hoddinott SN, Bass MJ. The dillman total design survey method. Can Fam Physician 1986;32:2366–2368. 34. Nunnally JC. Psyochometric theory. New York: McGraw-Hill; 1978. 35. Public Health Agency of Canada. Life and breath: respiratory diseases in Canada. Ottawa, Canada: Public Health Agency of Canada;2007:129p. 36. Kolbe J. Asthma education, action plans, psychosocial issues and adherence. Can Respir J 1999;6:273–280. 37. Yoon R, McKenzie DK, Miles DA, Bauman A. Characteristics of attenders and non-attenders at an asthma education programme. Thorax 1991;46:886–890. 38. Malo JL, Ghezzo H, L’Archeveˆque J, Lagier F, Perrin B, Cartier A. Is the clinical history a satisfactory means of diagnosing occupational asthma? Am Rev Respir Dis 1991;143:528–532.
J Asthma, 2015; 52(3): 279–288
39. Coˆte´ J, Kennedy S, Chan-Yeung M. Sensitivity and specificity of PC20 and peak expiratory flow rate in cedar asthma. J Allergy Clin Immunol 1990;85:592–598. 40. Baur X, Huber H, Degens PO, Allmers H, Ammon J. Relation between occupational asthma case history, bronchial methacholine challenge, and specific challenge test in patients with suspected occupational asthma. Am J Ind Med 1998;33:114–122. 41. Vandenplas O, Binard-Van Cangh F, Brumagne A, Caroyer JM, Thimpont J, Sohy C, Larbanois A, et al. Occupational asthma in symptomatic workers exposed to natural rubber latex: evaluation of diagnostic procedures. J Allergy Clin Immunol 2001;107:542–547. 42. Pralong JA, Moullec G, Suarthana E, Ge´rin M, Gautrin D, Archeveˆque JL, Labrecque M. Screening for occupational asthma by using a self-administered questionnaire in a clinical setting. J Occup Environ Med 2013;55:527–531. 43. Vandenplas O, Ghezzo H, Munoz X, Moscato G, Perfetti L, Lemie`re C, Labrecque M, et al. What are the questionnaire items most useful in identifying subjects with occupational asthma? Eur Respir J 2005;26:1056–1063.
