Accepted Manuscript Professional Autonomy and Work Setting as Contributing Factors to Depression and Absenteeism in Canadian Nurses Victoria Enns, B.A., Shawn Currie, Ph.D., JianLi Wang, Ph.D. PII:
S0029-6554(14)00293-0
DOI:
10.1016/j.outlook.2014.12.014
Reference:
YMNO 1011
To appear in:
Nursing Outlook
Received Date: 19 August 2014 Revised Date:
1 December 2014
Accepted Date: 17 December 2014
Please cite this article as: Enns V, Currie S, Wang J, Professional Autonomy and Work Setting as Contributing Factors to Depression and Absenteeism in Canadian Nurses, Nursing Outlook (2015), doi: 10.1016/j.outlook.2014.12.014. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
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Professional Autonomy and Work Setting as Contributing Factors to Depression and Absenteeism in
Victoria Enns, B.A. a
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Shawn Currie, Ph.D. a
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Canadian Nurses
JianLi Wang, Ph.D. b a
Department of Psychology, University of Calgary, 2500 University Drive NW, Calgary, Alberta, T2N 1N4, Canada
b
Department of Community Health Sciences and Psychiatry, University of Calgary,
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TRW Building 3rd Floor, 3280 Hospital Drive NW Calgary, Alberta CANADA T2N 4Z6
Name and address for correspondence and requests for reprints Shawn R. Currie, Ph.D. Director, Mental Health Information Management, Evaluation & Research Alberta Health Services, Mental Health and Addictions Services 10101 Southport Road SW Calgary, AB, Canada T2W 3N2 Phone: 403-943-2284; Fax: 403 943 0199. E-mail: [email protected].
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Contact:
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Professional Autonomy and Work Setting as Contributing Factors to Depression and Absenteeism in Canadian Nurses
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Abstract Background: The prevalence of major depression in Canadian nurses is double the national average for working women.
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Purpose: The present study sought to delineate the role of professional autonomy, healthcare setting and work environment characteristics as risk factors for depression and absenteeism in
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female nurses.
Method: A cross-sectional, secondary analysis was conducted on a large representative sample of female nurses working in hospitals and other settings across Canada (N = 17,437). Univariate and multivariate analyses were used to test the hypothesis that work environment factors are
for other risk factors.
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significant determinants of major depression and absenteeism in female nurses after accounting
Discussion: Experiencing a major depressive episode in the past 12 months was significantly associated with lower autonomy (odds ratio [OR] = 0.93), higher job strain (OR = 2.2), being a
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licensed practical nurse (OR = 0.82) and work in a non-hospital setting (OR = 1.5). Higher
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absenteeism was associated with the same variables as well as having less control over one's work schedule.
Conclusions: Efforts to increase autonomy of nurses and reduce job strain may help to address the high prevalence of major depression in this professional group.
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Professional Autonomy and Work Setting as Contributing Factors to Depression and Absenteeism in Canadian Nurses Introduction
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Nurses encounter a variety of stressors in their daily work including variable work shifts, close interactions with sick or dying individuals, repetitive tasks and heavy lifting, as well as coping with the demands of doctors, patients, and changing health care policies. The need to
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balance work and family responsibilities can cause additional stress for individuals working in a field that is still dominated by women. Nurses in Canada fall into three professional groups:
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registered nurses (RNs; 75% of all nurses), registered psychiatric nurses (RPNs; 2%), and licensed practical nurses (LPNs; 23%). The United States and United Kingdom have comparable nurse designations. Licensed practical nurses (23%) most often work in hospitals or long term care facilities, performing a more restricted range of activities than RNs or RPNs. As a
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professional group, LPNs are generally considered to have less authority to work independently than RNs or RPNs {White, 2008 5710 /id}.
The mental health of nurses, depression in particular, has emerged as a significant issue
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in this professional group {Shields, 2006 5721 /id}. World-wide, major depressive disorder (MDD) is the leading cause of disability and the second largest contributor to disease burden for
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young and middle-aged adults {Patten, 2006 5609 /id}. In the Global Burden of Disease Study major depression was the fourth leading cause of disease burden worldwide and expected to become the second leading cause by 2020 {Ustun, 2002 5535 /id}. The lifetime prevalence of major depressive disorder in Canadians is 12%, with a one-year prevalence of 5% among women.
In Canadian nurses, however, the one-year prevalence was found to be 10% {Ohler,
2010 5687 /id} or nearly double the Canadian average for employed women aged 25 to 61 years {Gilmour, 2007 5715 /id}. Research in other countries also shows a high prevalence rate of
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significant depression in working nurses. In a sample of 150 female medical-surgical nurses working in a southern United States hospital 21% scored in the severe range on the Center for Epidemiologic Studies Depression Scale (CESD){Welsh, 2009 5751 /id}. Studies of nurses working
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in French and Taiwan hospitals also show high rates of moderate to severe depression based on self-reported symptoms {Letvak, 2012 5748 /id;Jolivet, 2010 5750 /id}. This is a problematic finding for any workplace setting, as depression is known to carry a heavy disease burden and
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has been associated with poor concentration, declining work performance, absenteeism, and strained interpersonal functioning {Baba, 1999 5713 /id;Burton, 2004 5696 /id}. It is estimated
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that depression costs Canada approximately $14.4 billion per year, over half of which is due to work absences and lost productivity {Stephens, 2001 5700 /id}.
Established risk factors for depression in women include the presence of chronic medical conditions, low income, younger age, childhood trauma, marital status (single or divorced
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persons are highest risk), family history of depression, and comorbid mental disorders {Patten, 2006 5609 /id;Arboleda-Florez, 2001 5699 /id}. Research in the past decade has focused on the work environment as another potential risk factor in both the development and maintenance of
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depressive and anxiety disorders {Wang, 2010 6544 /id;Wang, 2010 5688 /id}. Research by Ohler and colleagues (2010) identified a number of individual and work-related factors that are
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associated with depression in nurses including role overload (an imbalance between available resources and the work demand), job strain, and lower perceived respect from superiors and colleagues.
The present study builds on this prior research to examine the impact of other important
work environment factors on the mental health and productivity of nurses. Our study focuses on two environmental influences that have not yet been studied as risk factors for depression in
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nurses: level of autonomy in the workplace and healthcare setting. Workplace autonomy has shown to be a robust predictor of both job retention and satisfaction in nurses {Hanson, 1990 5714 /id;Finn, 2001 5709 /id}. For example, among recently licensed RNs professional
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autonomy was shown to be significantly associated with overall commitment to the profession and nurses’ intention to remain in the field {Unruh, 2013 6619 /id}. A hypothetical link between workplace autonomy and depression is supported by self-determination theory {Gagne, 2005
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5706 /id} and the demand control model {Karasek, 1998 5566 /id;Karasek, 1979 5716 /id}. Selfdetermination theory posits that autonomy in the workplace is essential for the wellbeing of
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employees, and environments with low autonomy may lead to mental health problems. The demand control model of work stress asserts that employees in situations of high demand and low control are at the highest risk for stress disorders. Because nurses often perform tasks in high demand situations, a significant lack of control could be harmful to nurses.
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Healthcare setting is a measure of the work environment for nurses in the broadest sense. An acute care hospital is clearly distinguishable from other locations such as long-term care facilities or public health where the acuity and complexity of patients is generally lower. A
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survey of over 43,000 hospital nurses in five countries revealed 36% reported occupational burnout {Sochalski, 1999 5753 /id}. Respondents felt that both staffing levels and the level of
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support services were inadequate in acute care settings that rely on nursing to provide the majority of health care. Other research has shown that burnout in hospital nurses is associated with longer hours, higher patient-to-staff ratios, and lower job dissatisfaction {Bae, 2014 5742 /id;Stimpfel, 2012 5743 /id;McVicar, 2003 5744 /id}. Finally, hospital nurses are frequently victims of abuse {Duncan, 2000 5723 /id}. To date, no study has compared the mental health of nurses working in hospitals to nurses working in other healthcare settings. A better
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understanding of the relationship between workplace factors and mental health in nurses is essential to inform efforts to create a healthy work environment. The present study examines the relationship of workplace autonomy and healthcare
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setting (hospital versus other settings) to cases of major depression in female nurses. We
hypothesized that low autonomy and high job strain are independently associated with a higher likelihood of major depression and greater absenteeism. We further hypothesized that hospital-
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based nurses will have a significantly higher prevalence of major depression due to the
heightened psychological pressure of an acute care environment compared to nurses in other
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settings. In contrast to Ohler et al. (2010) we included LPNs in our study group. With LPNs generally having less independence we hypothesized this professional group would be at a higher risk for major depression compared to RNs and RPNs after controlling for other risk factors. Methods
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Study sample
This study used the 2005 National Survey of the Work and Health of Nurses (NSWHN). Detailed information on the survey is available in other sources {Shields, 2006 5721 /id}.
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Briefly, the NSWHN was the first large-scale, nationally representative survey conducted with Canada’s nurses and one of the largest direct surveys of women in the profession ever
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completed. The objective of the survey was to provide a complete picture of the working environment and health of individuals working in the field. A high response rate was achieved (80%) with the final sample being 18,676 nurses employed in a variety of positions, settings, and from all provinces and territories. Males were excluded from the present study due to the distinct gender difference in depression rates, and because they represent a relatively small
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subset (5%) of the Canadian nursing workforce. No other exclusion criteria were applied, resulting in a total of 17,437 female participants. Measures
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Four NSWHN variables assessing general working conditions and hypothesized to have a relationship with both autonomy and depression were coded into dichotomous variables:
healthcare setting, professional group, full-time status, and shift work. Setting was originally
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coded as hospital, long-term care, community health facilities and other settings. A preliminary analysis of depression by work settings revealed no significant variation in the prevalence of
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major depression across the long-term care, community health facilities, and other categories. Therefore, these settings were collapsed into a single category resulting in two categories for work setting: hospital versus other settings. Employment status was also a dichotomous variable coded as full-time (working 30 hours or more per week) or part-time (< 30 hours per week
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including casual). Shifts were coded as day shifts versus other shifts (evenings, nights, or mixed shifts). Professional group was divided into RNs and RPNs versus LPNs. The RN and RPN categories were merged because they have comparable training, scope of professional practice,
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and because the proportion of RPNs in the sample was very small (< 2%). Autonomy was assessed using three different measures. Two of these measures,
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autonomy and control over practice, are subscales from the Nursing Work Index-Revised (NWIR){Aiken, 2000 5724 /id}. The NWI-R is well established measure of the practice environment for nurses. The autonomy scale is composed of five questions concerning the freedom to make important care and work decisions, and the support from supervisors and managers when doing so. The control over practice scale is comprised of seven questions that assess the respondents’ ability to perform their jobs to their satisfaction with the supports available. Both scales had high
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internal consistency within the NSWHN sample (Cronbach’s alphas were 0.93 and 0.91 for the autonomy and control over practice scales, respectively). Control over work schedule is another dimension of workplace autonomy. Respondents
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were asked if they had control over their scheduled work days and work hours, and if they could actually chose their work days or work hours. Each answer to the affirmative was coded as one, while each negative answer was coded as zero. This resulted in a scale from zero to four, with
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zero indicating no schedule flexibility and four indicating complete control over one’s schedule. Job strain was assessed with the job strain ratio (JSR), a composite measure related to the
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demand control theory {Karasek, 1979 5716 /id}. Items for the JSR derived from a brief version of the Job Content Questionnaire developed to measure perceived work stress. This 12item scale evaluated work stress in 6 dimensions: skill discretion, decision control, psychological demands, job insecurity, physical exertion, and social support from supervisors and coworkers.
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The JSR was calculated as psychological demand (two items) divided by the sum of decision authority (two items) and skill discretion (three items). Scores were calculated by assigning a value between 4 (strongly agree) and 0 (strongly disagree) to each item and then summing the
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item scores for each component. Scores were pro-rated to ensure that the potential contributions of the numerator (psychological demands) and decision latitude (decision control plus skill
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discretion) were equal. A small constant (0.1) was added to the numerator and denominator to avoid division by 0. If workplace demands are higher than the individual’s expertise and control, the resulting number was above one, indicating a high demand, low control situation. This situation is most likely to produce workplace stress. Because of the skewed distribution of JSR scores, respondents were classified for this analysis as having high job strain if the value of the ratio was 1.2 or higher, which corresponds to the 75th percentile for the range on this measure in
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a random sample from the Canadian population {Wang, 2005 6618 /id}. Control over work schedule, job strain, and the two NWI-R scales (autonomy and control over practice) were all significantly correlated (ps < .001) with coefficients ranging from -0.19 (JSR and control over
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work schedule) to 0.61 (autonomy and control over practice NWI-R scales) indicating each variable provided related but not redundant information on the nursing work environment.
Because none of the bivariate correlations exceeded 0.70, multicollinearity was not viewed as a
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concern for the regression analyses {Tabachnick, 2012 5746 /id}.
We examined two outcome variables: presence of a major depressive episode (MDE) and
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work absences. Major depressive episodes were assessed using the short form of the Composite International Diagnostic Interview (CIDI). The CIDI is a structured interview administered by non-clinicians that identifies the occurrence of a MDE based on symptoms listed by the Diagnostic and Statistical Manual of Mental Disorders-3rd revised edition {American Psychiatric
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Association, 1987 5748 /id}. A positive response to one of two preliminary questions (feeling sad or depressed/loss of interest for two weeks in a row within the last year) led to a second question concerning daily occurrence. Participants who reported feeling sad or a lack of interest
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for most of the day or all of the day during the two week period were asked the remainder of the questions, which enquired after depressive symptoms such as loss of concentration, thoughts of
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death, weight change and sleeping patterns. For the present analysis, we used the CIDI dichotomous score for major depression that identifies the presence or absence of a MDE based on endorsing five or more symptoms (one of which must include the feeling sad or depressed or reporting loss of interest for two weeks in a row most of the day or all of the day). Research on the performance of the CIDI compared to a full diagnostic interview has shown that adults who meet these criteria have a 90% or more likelihood of experiencing a MDE in the previous 12
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months {Kurdyak, 2005 5695 /id}. The CIDI depression module also has a continuous scale score which ranges from 0 to 8 however because of the skipping rules imposed in the short form respondents who answer no to the screening questions (feeling sad or lose of interest) are
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assigned a zero for the remaining symptoms despite not being administered the questions.
We also examined the number of days absent from work for sickness as an objective indicator of work impact from stress and depression. With a median value of zero and mean of
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13.4, work absences was highly skewed (Skewness = 5.68). The distribution improved with the application of a natural log transformation (Skewness = 0.15).
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Statistical analysis
The NSWHN sample weights, which adjust for the exclusion of survey non-respondents in the final sample, were used in all univariate and bivariate analyses. The bootstrap weights provided by Statistics Canada were used to estimate standard errors and 95% confidence
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intervals for the final regression models. Prior to conducting regression models, patterns of autonomy were first examined across the workplace factors and demographics to understand characteristics associated with high and low levels of autonomy. Using independent t-tests mean
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scores on JSR and the three measures of autonomy (autonomy scale, control over practice scale, and schedule flexibility) were compared using the grouping variables of healthcare setting
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(hospital vs. other settings) and professional group (LPN vs RN/PRN). The relationship of depression and workplace factors, demographic variables, and other personal characteristics was explored with chi-square procedures. For statistical comparisons of proportions, the chi-square value for each test is corrected for the survey design and converted to an F statistic {Rao, 1984 5745 /id}. The NSWHN used sampling weights that adjust for its complex design; such weights cannot be used in a traditional chi-square calculation.
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Logistic and linear regression models were constructed in order to determine the relative contribution of each variable in predicting major depression and number of work absences after accounting for demographic factors. Logistic regression was used to predict the presence or
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absence of major depression based on the CIDI categorical variable. We determined a priori to include the measures of autonomy, healthcare setting, job strain, and professional group (LPN vs RN/PRN) in the models. In addition, age, marital status, and chronic conditions were included in
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the model due to their established relationship with depression. Inclusion of any remaining variables in the models was based on a significant relationship with the presence or absence of
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depression. Using the same predictors, linear regression examined the strength of each factor in assessing the number of illness related absences.
Results
Sample characteristics
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Sample characteristics are provided in Table 1. The 12-month prevalence of major depressive episode was 9.3%. Nine percent of the sample had also used antidepressants in the past month. The prevalence of depression was significantly associated with younger age
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(t[df=17423] = 3.66, p = .0002) although the age difference between depressed and non-depressed nurses was not clinically meaningful (44.43 [SD =10.63] versus 43.33 [SD = 9.63]). Self-rated
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physical health was generally high (67% reported very good or excellent health) though 73% of nurses reported one or more chronic health problems. Most nurses (53%) reported they had no control over their schedule; a small proportion (14%) had complete control over their work schedule.
Work environment, depression, and absenteeism
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Table 2 displays the mean differences for the continuous predictor variables using the grouping variables of work setting and professional group. Scores on the Job Strain Ratio and the three measures of autonomy show a relationship with both factors. Nurses working in hospitals
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had lower scores on the autonomy and control over practice scales and reported less schedule flexibility compared to nurses in other settings. Differences between LPNs and RN/RPNs were also found with the latter group displaying higher scores on autonomy, control over practice,
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schedule flexibility while having lower job strain. A high proportion of nurses (24%) displayed a JSR over 1.2.
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The relationship of major depression and absenteeism to work setting and professional group is also shown on Table 2. Work setting was associated with a difference in the prevalence of major depression but in the opposite direction of our prediction. Hospital-based nurses showed lower levels of depression compared to nurses working outside of hospitals. Workplace
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absences were significantly higher in nurses who were employed as LPNs and those who worked in a hospital. Depression and absenteeism were very highly related. Individuals who met the criteria for major depression were absent a mean of 46.5 days (SD = 81.6) in the previous year,
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whereas those who did not meet the criteria for major depression were absent for an average of 11.2 days (SD = 36.2) (t[df=17005] = 31.33, p < .0001).
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Depression was also significantly associated with the three autonomy measures and job
strain. As hypothesized, depressed nurses had lower scores on the autonomy scale (8.9) of the NWI-R (t[df=14422] = 18.60, p < .0001) compared to the non-depressed group (10.6). Control over practice scores was also significantly lower (t[df=14345] = 16.36, p < .0001) in depressed individuals (10.2 vs. 12.3 for non-depressed group). Non-depressed nurses reported greater schedule flexibility than depressed nurses (1.2 vs. 0.97 respectively; t[df=17174] = 5.59, p < .0001)
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and job strain was higher in depressed nurses compared to non-depressed nurse (1.2 vs. 1.0 respectively; t[df=17024] = 18.65, p < .0001). This latter effect was explored further by stratifying the job strain ratio into quartiles, which demonstrated a curvilinear relationship with depression
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(Figure 1). A post hoc Scheffe test indicated no statistical difference between the first and second quartiles in job strain ratio (5.6% depressed versus 6.3%, respectively, p = .755). However, the second and third quartiles were significantly different (p < .0001), as well as the third and the
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fourth quartiles (p < .0001). The prevalence of major depression within the highest quartile for
experiencing the least job strain (5.6%).
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job strain are 16.0%, almost three times higher than depression rates in the quartile of nurses
Logistic regression was used to estimate the likelihood of having experienced a major depressive episode based on the work environment factors while controlling for established risk factors for depression. The overall model was significant (F = 26.67, p < .0001) although the
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combination of predictors only accounted for 9% of the variance in the presence or absence of major depression (see Table 3). Age, chronic conditions, and marital status remained significant predictors of depression. Nurses who were divorced or widowed were 1.8 times more likely to
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have a major depressive episode compared to married or single women. The presence of a chronic medical condition was the strongest overall predictor (OR = 3.4).
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Job strain maintained a strong relationship to depression, with higher levels of job strain
associated with a greater likelihood of major depression. The autonomy scale also showed a significant relationship to depression, with lower rates of autonomy predicting higher rates of depression. Greater control over practice was associated with lower risk of depression (p < .0001), but schedule flexibility was no longer a significant predictor. Work setting (hospital
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versus other) continued to maintain a significant relationship with depression, with hospitalbased nurses being at a lower risk. Using the same predictors, a linear regression model was run with the log of illness-
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related work absences as the dependent variable (Table 3). The combination of predictors
accounted for a similar proportion of variance in work absences as the depression model (F = 49.73, p < .0001; R2 = .08). As with major depression, age and chronic condition significantly
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predicted work absences. Job strain, autonomy, and control over practice were also significant predictors of work absences (p < .001). A one unit increase in the NWI-R autonomy scale
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decreases time absent by a factor of 0.97 and a unit increase in schedule flexibility decreases time absent by a factor of 0.92. In contrast to the model predicting major depression, greater schedule flexibility was significantly associated with fewer work absences. Hospital nurses also had more work absences. Nurses who worked evenings and nights were more likely to be absent
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from work.
Discussion
The overall 12-month prevalence of major depression in female nurses was 9.3% or
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nearly twice the prevalence in Canadian women in research conducted during the same time period {Patten, 2006 5609 /id}. Consistent with previous research, the prevalence of major
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depression was higher in nurses who were younger, divorced or widowed, and reported at least one chronic medical condition. Comparable rates of depression were found in LPNs and RN/RPNs however, professional group emerged as a modest but significant determinant of depression in the regression model. Days absent for illness were significantly higher in LPNs compared to RN/RPNs in both univariate testing and in the presence of other predictors in the regression modeling.
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The present results confirm a strong relationship between several work environment factors and major depression in nurses. Among the work environment factors examined, job strain had the strongest impact on both major depression and absenteeism. The relationship
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between the JSR and prevalence of depression in nurses is best described as curvilinear with no significant difference in prevalence at the lowest quartiles. However, when job strain exceeds the 50th percentile, the impact on depression is very apparent. In particular, there was a large and
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significant difference in depression prevalence between the third and fourth quartiles. Using the identical measures, Wang and colleagues also found a robust relationship between job strain and
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major depression within a randomly selected sample of Canadian working women {Wang, 2012 5717 /id}. Wang et al.’s findings differed, however, in two ways. First, the lowest rate of depression in women was observed in the second quartile of job strain suggesting that a mild degree of work stress may have protective benefits. Wang et al. also found no significant
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difference in depression prevalence for women in the third and fourth quartiles of job strain. In the present study, nurses appear to be more vulnerable to declining mental health as job strain increases. Even at the upper quartile of the JSR scores, the prevalence of major depression was
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only 6% in the Wang et al. sample of working women compared to 16% in nurses. Our analysis of autonomy produced some mixed findings but generally confirm our
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original hypothesis that greater workplace autonomy is associated with lower prevalence of depression and fewer work absences. Both the autonomy and control over practice scales from the NWI-R were significant determinants of depression and work absences after controlling for other influences including job strain. Prior research demonstrated a strong relationship between high autonomy and greater work satisfaction in nurses {Finn, 2001 5709 /id}. The present study shows that high autonomy is also associated with less depression and work absences. Control
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over practice as measured by the NWI-R assesses a different but related dimension of autonomy. Higher ratings on this scale are reported by nurses who felt their skills were fully utilized to provide quality patient care. Like autonomy, higher control over practice was associated with
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reduced prevalence of major depression and absenteeism. Having control over one’s schedule had no impact on depression but was associated with better work attendance. Schedule
flexibility remained a strong determinant of absenteeism even with chronic conditions in the
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model suggesting missed work was not solely due to ongoing medical problems. This finding supports a proposal from the nursing profession to allow nurses to self-schedule their shifts, a
absences {Dechant, 1990 5720 /id}.
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practice predicted to increase staff satisfaction, improve staff retention and lead to fewer work
General conditions of employment had little impact on the prevalence of depression with the exception of work setting. Contrary to our prediction, the prevalence of major depression in
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hospital-based nurses was lower than nurses working in other settings. Healthcare setting was significantly associated with depression even after controlling for other variables including job strain and chronic conditions. The fact that work setting was not associated with work absences
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also suggests its relationship to depression is not simply due to hospital workers having greater exposure to illness. The lower risk in hospital nurses could due to personal hardiness and self-
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selection to this work environment. Nurses with higher levels of hardiness may choose to work in hospitals where the work pace and complexity of patients is greater than other settings. Research has shown that individuals with higher levels of personal hardiness are less likely to be diagnosed with major depression {Maddi, 2006 5704 /id;Clark, 2002 5698 /id}. Nurses with lower levels of hardiness may gravitate to other health care settings. It is noteworthy that the
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overall prevalence of depression in non-hospital nurses was still substantially higher than the female working population {Gilmour, 2007 5715 /id}. Among the risk factors studied, the presence of one or more chronic conditions had the
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strongest influence on both depression and absenteeism. Seventy-three percent of nurses
reported having at least one chronic condition, a rate that is higher than the general Canadian population reported from surveys using the identical list of chronic condition {Patten, 2005 5718
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/id}. Nurses may have a higher rate due to the workforce being older (over 50% are over 45 years old), exposure to illness, and the physically demanding nature of the work. Both RNs and
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LPNs are often called upon to lift patients or equipment, subjecting them to musculoskeletal injuries. The likelihood of injury can be reduced by the use of lifting aids yet 36% of nurses in the NSWHN who were required to lift or transfer patients indicated that the necessary equipment was frequently unavailable {Shields, 2006 5721 /id}.
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As a secondary analysis of cross-sectional data, our study has some obvious limitations deserving acknowledgement. Foremost, we cannot establish a causal link between work environment and depression although compelling evidence that work environment factors do
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predict future major depression has emerged in a recent longitudinal study by our research team. Over a one year interval, both higher job strain and greater work-to-family conflict predicted
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future onset of major depression in working women {Wang, 2012 5717 /id}. Longitudinal research in other countries has produced similar finding. In an earlier review, the relative risk ratio of developing depression when exposed to high job stress was found to be approximately 2.0 across studies {Netterstrom, 2008 5745 /id}. Nonetheless, we need to consider alternative hypotheses to explain the nature of the relationships shown in our cross-sectional data. For example, it is possible that nurses with chronic depression self-select positions with lower
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autonomy and less flexibility in working conditions. Depressed nurses may also have job performance issues, leading them to migrate toward positions with less independence or authority to make decisions.
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All workplace factor measures used were based on self-report and there was no
independent verification of levels of job strain, autonomy, and control over practice. It is
possible that the relationship between some of the variables and depression is influenced by a
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negative outlook, where depressed nurses perceive their work environment as more stressful than non-depressed nurses. This is an often cited limitation of studies on workplace and psychosocial
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factors in which both the exposure (work environment) and outcome (depression) are assessed using self-report {Netterstrom, 2008 5745 /id}. We attempted to compensate for this limitation, referred to as the common method bias, by including a less subjective outcome measure, number illness-related absences, in addition to self-reported depression.
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The use of a structured diagnostic interview to identify cases of clinically significant depression is a notable strength of the NSWHN. Prior studies on depression in nurses have relied on self-administered symptom scales such as the CESD. We acknowledge that the
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NSWHN version of the CIDI was an older interview schedule that uses DSM III-R criteria. However, the criteria of the DSM-III and DSM-IV are relatively similar to each other, and there
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is strong evidence that the CIDI is able to successfully diagnose DSM-IV depression {Kurdyak, 2005 5695 /id}. Furthermore, because the criteria for a MDE did not change in the DSM 5 {American Psychiatric Association, 2013 5747 /id}, we can conclude the CIDI-derived classification of major depression is also consistent with the latest edition of the DSM. Finally, the data were collected in 2005-2006. Despite the survey results being almost a decade old, there is no clear indication that the work environment for nurses has markedly improved. In fact,
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some scholars feel that job strain is getting worse for nurses in many countries as healthcare budgets are reduced and patient volumes are increasing {Buchan, 2013 5742 /id}. Furthermore, the general aging trend in the population is having a negative effect on the nursing workforce.
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Experienced nurses are retiring and the recruitment of new nurses into the profession is not keeping pace with the population growth resulting in additional strain on the remaining
workforce. In addition to workload, lack of autonomy and feelings of disempowerment are
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factors associated with nursing turnover {Hayes, 2012 5743 /id}.
Future research is warranted to inform and extend the results of this study. The finding
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that hospital-based nurses have less depression requires replication. The role of hardiness and other protective factors should be explored in the same study. It would also be important to determine if the overall results, in particular the role of autonomy in depression prevalence, would be replicated in a large sample of male nurses. The strongest evidence of causation would
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come from a longitudinal study. We have conducted such as a study on a sample from the general working population in Alberta {Wang, 2012 5717 /id}. Unfortunately, the sample of health care workers is too small for a meaningful analysis of work environment predicting future
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depression. A longitudinal study focused on new graduates from nursing would provide
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invaluable data on the role of work environment on future mental health.
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Table 1 Sample characteristics and workplace factors (N = 17,437) Weighted %
95% Confidence Interval
Age Group
Position RN/RPN LPN
Full-time Part-time Shift work
74.88 12.18 1.81 10.88
73.86 11.40 1.50 10.15
-
21.39 28.29 35.52 18.83
-
75.90 12.96 2.12 11.61
56.47 43.52
55.33 42.38
-
57.61 44.66
79.16 19.56
78.47 18.87
-
79.85 20.25
59.02 38.70
-
61.30 40.98
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Hours
19.43 26.17 33.28 17.07
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Marital status Married/common-law Single Widowed Separated/divorced Work setting Hospital Other
20.41 27.23 34.40 17.95
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S0029-6554(14)00293-0
DOI:
10.1016/j.outlook.2014.12.014
Reference:
YMNO 1011
To appear in:
Nursing Outlook
Received Date: 19 August 2014 Revised Date:
1 December 2014
Accepted Date: 17 December 2014
Please cite this article as: Enns V, Currie S, Wang J, Professional Autonomy and Work Setting as Contributing Factors to Depression and Absenteeism in Canadian Nurses, Nursing Outlook (2015), doi: 10.1016/j.outlook.2014.12.014. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
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Professional Autonomy and Work Setting as Contributing Factors to Depression and Absenteeism in
Victoria Enns, B.A. a
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Shawn Currie, Ph.D. a
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Canadian Nurses
JianLi Wang, Ph.D. b a
Department of Psychology, University of Calgary, 2500 University Drive NW, Calgary, Alberta, T2N 1N4, Canada
b
Department of Community Health Sciences and Psychiatry, University of Calgary,
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TRW Building 3rd Floor, 3280 Hospital Drive NW Calgary, Alberta CANADA T2N 4Z6
Name and address for correspondence and requests for reprints Shawn R. Currie, Ph.D. Director, Mental Health Information Management, Evaluation & Research Alberta Health Services, Mental Health and Addictions Services 10101 Southport Road SW Calgary, AB, Canada T2W 3N2 Phone: 403-943-2284; Fax: 403 943 0199. E-mail: [email protected].
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Contact:
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Professional Autonomy and Work Setting as Contributing Factors to Depression and Absenteeism in Canadian Nurses
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Abstract Background: The prevalence of major depression in Canadian nurses is double the national average for working women.
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Purpose: The present study sought to delineate the role of professional autonomy, healthcare setting and work environment characteristics as risk factors for depression and absenteeism in
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female nurses.
Method: A cross-sectional, secondary analysis was conducted on a large representative sample of female nurses working in hospitals and other settings across Canada (N = 17,437). Univariate and multivariate analyses were used to test the hypothesis that work environment factors are
for other risk factors.
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significant determinants of major depression and absenteeism in female nurses after accounting
Discussion: Experiencing a major depressive episode in the past 12 months was significantly associated with lower autonomy (odds ratio [OR] = 0.93), higher job strain (OR = 2.2), being a
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licensed practical nurse (OR = 0.82) and work in a non-hospital setting (OR = 1.5). Higher
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absenteeism was associated with the same variables as well as having less control over one's work schedule.
Conclusions: Efforts to increase autonomy of nurses and reduce job strain may help to address the high prevalence of major depression in this professional group.
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Professional Autonomy and Work Setting as Contributing Factors to Depression and Absenteeism in Canadian Nurses Introduction
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Nurses encounter a variety of stressors in their daily work including variable work shifts, close interactions with sick or dying individuals, repetitive tasks and heavy lifting, as well as coping with the demands of doctors, patients, and changing health care policies. The need to
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balance work and family responsibilities can cause additional stress for individuals working in a field that is still dominated by women. Nurses in Canada fall into three professional groups:
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registered nurses (RNs; 75% of all nurses), registered psychiatric nurses (RPNs; 2%), and licensed practical nurses (LPNs; 23%). The United States and United Kingdom have comparable nurse designations. Licensed practical nurses (23%) most often work in hospitals or long term care facilities, performing a more restricted range of activities than RNs or RPNs. As a
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professional group, LPNs are generally considered to have less authority to work independently than RNs or RPNs {White, 2008 5710 /id}.
The mental health of nurses, depression in particular, has emerged as a significant issue
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in this professional group {Shields, 2006 5721 /id}. World-wide, major depressive disorder (MDD) is the leading cause of disability and the second largest contributor to disease burden for
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young and middle-aged adults {Patten, 2006 5609 /id}. In the Global Burden of Disease Study major depression was the fourth leading cause of disease burden worldwide and expected to become the second leading cause by 2020 {Ustun, 2002 5535 /id}. The lifetime prevalence of major depressive disorder in Canadians is 12%, with a one-year prevalence of 5% among women.
In Canadian nurses, however, the one-year prevalence was found to be 10% {Ohler,
2010 5687 /id} or nearly double the Canadian average for employed women aged 25 to 61 years {Gilmour, 2007 5715 /id}. Research in other countries also shows a high prevalence rate of
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significant depression in working nurses. In a sample of 150 female medical-surgical nurses working in a southern United States hospital 21% scored in the severe range on the Center for Epidemiologic Studies Depression Scale (CESD){Welsh, 2009 5751 /id}. Studies of nurses working
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in French and Taiwan hospitals also show high rates of moderate to severe depression based on self-reported symptoms {Letvak, 2012 5748 /id;Jolivet, 2010 5750 /id}. This is a problematic finding for any workplace setting, as depression is known to carry a heavy disease burden and
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has been associated with poor concentration, declining work performance, absenteeism, and strained interpersonal functioning {Baba, 1999 5713 /id;Burton, 2004 5696 /id}. It is estimated
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that depression costs Canada approximately $14.4 billion per year, over half of which is due to work absences and lost productivity {Stephens, 2001 5700 /id}.
Established risk factors for depression in women include the presence of chronic medical conditions, low income, younger age, childhood trauma, marital status (single or divorced
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persons are highest risk), family history of depression, and comorbid mental disorders {Patten, 2006 5609 /id;Arboleda-Florez, 2001 5699 /id}. Research in the past decade has focused on the work environment as another potential risk factor in both the development and maintenance of
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depressive and anxiety disorders {Wang, 2010 6544 /id;Wang, 2010 5688 /id}. Research by Ohler and colleagues (2010) identified a number of individual and work-related factors that are
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associated with depression in nurses including role overload (an imbalance between available resources and the work demand), job strain, and lower perceived respect from superiors and colleagues.
The present study builds on this prior research to examine the impact of other important
work environment factors on the mental health and productivity of nurses. Our study focuses on two environmental influences that have not yet been studied as risk factors for depression in
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nurses: level of autonomy in the workplace and healthcare setting. Workplace autonomy has shown to be a robust predictor of both job retention and satisfaction in nurses {Hanson, 1990 5714 /id;Finn, 2001 5709 /id}. For example, among recently licensed RNs professional
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autonomy was shown to be significantly associated with overall commitment to the profession and nurses’ intention to remain in the field {Unruh, 2013 6619 /id}. A hypothetical link between workplace autonomy and depression is supported by self-determination theory {Gagne, 2005
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5706 /id} and the demand control model {Karasek, 1998 5566 /id;Karasek, 1979 5716 /id}. Selfdetermination theory posits that autonomy in the workplace is essential for the wellbeing of
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employees, and environments with low autonomy may lead to mental health problems. The demand control model of work stress asserts that employees in situations of high demand and low control are at the highest risk for stress disorders. Because nurses often perform tasks in high demand situations, a significant lack of control could be harmful to nurses.
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Healthcare setting is a measure of the work environment for nurses in the broadest sense. An acute care hospital is clearly distinguishable from other locations such as long-term care facilities or public health where the acuity and complexity of patients is generally lower. A
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survey of over 43,000 hospital nurses in five countries revealed 36% reported occupational burnout {Sochalski, 1999 5753 /id}. Respondents felt that both staffing levels and the level of
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support services were inadequate in acute care settings that rely on nursing to provide the majority of health care. Other research has shown that burnout in hospital nurses is associated with longer hours, higher patient-to-staff ratios, and lower job dissatisfaction {Bae, 2014 5742 /id;Stimpfel, 2012 5743 /id;McVicar, 2003 5744 /id}. Finally, hospital nurses are frequently victims of abuse {Duncan, 2000 5723 /id}. To date, no study has compared the mental health of nurses working in hospitals to nurses working in other healthcare settings. A better
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understanding of the relationship between workplace factors and mental health in nurses is essential to inform efforts to create a healthy work environment. The present study examines the relationship of workplace autonomy and healthcare
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setting (hospital versus other settings) to cases of major depression in female nurses. We
hypothesized that low autonomy and high job strain are independently associated with a higher likelihood of major depression and greater absenteeism. We further hypothesized that hospital-
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based nurses will have a significantly higher prevalence of major depression due to the
heightened psychological pressure of an acute care environment compared to nurses in other
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settings. In contrast to Ohler et al. (2010) we included LPNs in our study group. With LPNs generally having less independence we hypothesized this professional group would be at a higher risk for major depression compared to RNs and RPNs after controlling for other risk factors. Methods
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Study sample
This study used the 2005 National Survey of the Work and Health of Nurses (NSWHN). Detailed information on the survey is available in other sources {Shields, 2006 5721 /id}.
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Briefly, the NSWHN was the first large-scale, nationally representative survey conducted with Canada’s nurses and one of the largest direct surveys of women in the profession ever
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completed. The objective of the survey was to provide a complete picture of the working environment and health of individuals working in the field. A high response rate was achieved (80%) with the final sample being 18,676 nurses employed in a variety of positions, settings, and from all provinces and territories. Males were excluded from the present study due to the distinct gender difference in depression rates, and because they represent a relatively small
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subset (5%) of the Canadian nursing workforce. No other exclusion criteria were applied, resulting in a total of 17,437 female participants. Measures
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Four NSWHN variables assessing general working conditions and hypothesized to have a relationship with both autonomy and depression were coded into dichotomous variables:
healthcare setting, professional group, full-time status, and shift work. Setting was originally
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coded as hospital, long-term care, community health facilities and other settings. A preliminary analysis of depression by work settings revealed no significant variation in the prevalence of
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major depression across the long-term care, community health facilities, and other categories. Therefore, these settings were collapsed into a single category resulting in two categories for work setting: hospital versus other settings. Employment status was also a dichotomous variable coded as full-time (working 30 hours or more per week) or part-time (< 30 hours per week
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including casual). Shifts were coded as day shifts versus other shifts (evenings, nights, or mixed shifts). Professional group was divided into RNs and RPNs versus LPNs. The RN and RPN categories were merged because they have comparable training, scope of professional practice,
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and because the proportion of RPNs in the sample was very small (< 2%). Autonomy was assessed using three different measures. Two of these measures,
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autonomy and control over practice, are subscales from the Nursing Work Index-Revised (NWIR){Aiken, 2000 5724 /id}. The NWI-R is well established measure of the practice environment for nurses. The autonomy scale is composed of five questions concerning the freedom to make important care and work decisions, and the support from supervisors and managers when doing so. The control over practice scale is comprised of seven questions that assess the respondents’ ability to perform their jobs to their satisfaction with the supports available. Both scales had high
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internal consistency within the NSWHN sample (Cronbach’s alphas were 0.93 and 0.91 for the autonomy and control over practice scales, respectively). Control over work schedule is another dimension of workplace autonomy. Respondents
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were asked if they had control over their scheduled work days and work hours, and if they could actually chose their work days or work hours. Each answer to the affirmative was coded as one, while each negative answer was coded as zero. This resulted in a scale from zero to four, with
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zero indicating no schedule flexibility and four indicating complete control over one’s schedule. Job strain was assessed with the job strain ratio (JSR), a composite measure related to the
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demand control theory {Karasek, 1979 5716 /id}. Items for the JSR derived from a brief version of the Job Content Questionnaire developed to measure perceived work stress. This 12item scale evaluated work stress in 6 dimensions: skill discretion, decision control, psychological demands, job insecurity, physical exertion, and social support from supervisors and coworkers.
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The JSR was calculated as psychological demand (two items) divided by the sum of decision authority (two items) and skill discretion (three items). Scores were calculated by assigning a value between 4 (strongly agree) and 0 (strongly disagree) to each item and then summing the
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item scores for each component. Scores were pro-rated to ensure that the potential contributions of the numerator (psychological demands) and decision latitude (decision control plus skill
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discretion) were equal. A small constant (0.1) was added to the numerator and denominator to avoid division by 0. If workplace demands are higher than the individual’s expertise and control, the resulting number was above one, indicating a high demand, low control situation. This situation is most likely to produce workplace stress. Because of the skewed distribution of JSR scores, respondents were classified for this analysis as having high job strain if the value of the ratio was 1.2 or higher, which corresponds to the 75th percentile for the range on this measure in
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a random sample from the Canadian population {Wang, 2005 6618 /id}. Control over work schedule, job strain, and the two NWI-R scales (autonomy and control over practice) were all significantly correlated (ps < .001) with coefficients ranging from -0.19 (JSR and control over
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work schedule) to 0.61 (autonomy and control over practice NWI-R scales) indicating each variable provided related but not redundant information on the nursing work environment.
Because none of the bivariate correlations exceeded 0.70, multicollinearity was not viewed as a
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concern for the regression analyses {Tabachnick, 2012 5746 /id}.
We examined two outcome variables: presence of a major depressive episode (MDE) and
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work absences. Major depressive episodes were assessed using the short form of the Composite International Diagnostic Interview (CIDI). The CIDI is a structured interview administered by non-clinicians that identifies the occurrence of a MDE based on symptoms listed by the Diagnostic and Statistical Manual of Mental Disorders-3rd revised edition {American Psychiatric
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Association, 1987 5748 /id}. A positive response to one of two preliminary questions (feeling sad or depressed/loss of interest for two weeks in a row within the last year) led to a second question concerning daily occurrence. Participants who reported feeling sad or a lack of interest
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for most of the day or all of the day during the two week period were asked the remainder of the questions, which enquired after depressive symptoms such as loss of concentration, thoughts of
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death, weight change and sleeping patterns. For the present analysis, we used the CIDI dichotomous score for major depression that identifies the presence or absence of a MDE based on endorsing five or more symptoms (one of which must include the feeling sad or depressed or reporting loss of interest for two weeks in a row most of the day or all of the day). Research on the performance of the CIDI compared to a full diagnostic interview has shown that adults who meet these criteria have a 90% or more likelihood of experiencing a MDE in the previous 12
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months {Kurdyak, 2005 5695 /id}. The CIDI depression module also has a continuous scale score which ranges from 0 to 8 however because of the skipping rules imposed in the short form respondents who answer no to the screening questions (feeling sad or lose of interest) are
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assigned a zero for the remaining symptoms despite not being administered the questions.
We also examined the number of days absent from work for sickness as an objective indicator of work impact from stress and depression. With a median value of zero and mean of
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13.4, work absences was highly skewed (Skewness = 5.68). The distribution improved with the application of a natural log transformation (Skewness = 0.15).
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Statistical analysis
The NSWHN sample weights, which adjust for the exclusion of survey non-respondents in the final sample, were used in all univariate and bivariate analyses. The bootstrap weights provided by Statistics Canada were used to estimate standard errors and 95% confidence
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intervals for the final regression models. Prior to conducting regression models, patterns of autonomy were first examined across the workplace factors and demographics to understand characteristics associated with high and low levels of autonomy. Using independent t-tests mean
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scores on JSR and the three measures of autonomy (autonomy scale, control over practice scale, and schedule flexibility) were compared using the grouping variables of healthcare setting
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(hospital vs. other settings) and professional group (LPN vs RN/PRN). The relationship of depression and workplace factors, demographic variables, and other personal characteristics was explored with chi-square procedures. For statistical comparisons of proportions, the chi-square value for each test is corrected for the survey design and converted to an F statistic {Rao, 1984 5745 /id}. The NSWHN used sampling weights that adjust for its complex design; such weights cannot be used in a traditional chi-square calculation.
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Logistic and linear regression models were constructed in order to determine the relative contribution of each variable in predicting major depression and number of work absences after accounting for demographic factors. Logistic regression was used to predict the presence or
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absence of major depression based on the CIDI categorical variable. We determined a priori to include the measures of autonomy, healthcare setting, job strain, and professional group (LPN vs RN/PRN) in the models. In addition, age, marital status, and chronic conditions were included in
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the model due to their established relationship with depression. Inclusion of any remaining variables in the models was based on a significant relationship with the presence or absence of
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depression. Using the same predictors, linear regression examined the strength of each factor in assessing the number of illness related absences.
Results
Sample characteristics
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Sample characteristics are provided in Table 1. The 12-month prevalence of major depressive episode was 9.3%. Nine percent of the sample had also used antidepressants in the past month. The prevalence of depression was significantly associated with younger age
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(t[df=17423] = 3.66, p = .0002) although the age difference between depressed and non-depressed nurses was not clinically meaningful (44.43 [SD =10.63] versus 43.33 [SD = 9.63]). Self-rated
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physical health was generally high (67% reported very good or excellent health) though 73% of nurses reported one or more chronic health problems. Most nurses (53%) reported they had no control over their schedule; a small proportion (14%) had complete control over their work schedule.
Work environment, depression, and absenteeism
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Table 2 displays the mean differences for the continuous predictor variables using the grouping variables of work setting and professional group. Scores on the Job Strain Ratio and the three measures of autonomy show a relationship with both factors. Nurses working in hospitals
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had lower scores on the autonomy and control over practice scales and reported less schedule flexibility compared to nurses in other settings. Differences between LPNs and RN/RPNs were also found with the latter group displaying higher scores on autonomy, control over practice,
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schedule flexibility while having lower job strain. A high proportion of nurses (24%) displayed a JSR over 1.2.
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The relationship of major depression and absenteeism to work setting and professional group is also shown on Table 2. Work setting was associated with a difference in the prevalence of major depression but in the opposite direction of our prediction. Hospital-based nurses showed lower levels of depression compared to nurses working outside of hospitals. Workplace
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absences were significantly higher in nurses who were employed as LPNs and those who worked in a hospital. Depression and absenteeism were very highly related. Individuals who met the criteria for major depression were absent a mean of 46.5 days (SD = 81.6) in the previous year,
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whereas those who did not meet the criteria for major depression were absent for an average of 11.2 days (SD = 36.2) (t[df=17005] = 31.33, p < .0001).
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Depression was also significantly associated with the three autonomy measures and job
strain. As hypothesized, depressed nurses had lower scores on the autonomy scale (8.9) of the NWI-R (t[df=14422] = 18.60, p < .0001) compared to the non-depressed group (10.6). Control over practice scores was also significantly lower (t[df=14345] = 16.36, p < .0001) in depressed individuals (10.2 vs. 12.3 for non-depressed group). Non-depressed nurses reported greater schedule flexibility than depressed nurses (1.2 vs. 0.97 respectively; t[df=17174] = 5.59, p < .0001)
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and job strain was higher in depressed nurses compared to non-depressed nurse (1.2 vs. 1.0 respectively; t[df=17024] = 18.65, p < .0001). This latter effect was explored further by stratifying the job strain ratio into quartiles, which demonstrated a curvilinear relationship with depression
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(Figure 1). A post hoc Scheffe test indicated no statistical difference between the first and second quartiles in job strain ratio (5.6% depressed versus 6.3%, respectively, p = .755). However, the second and third quartiles were significantly different (p < .0001), as well as the third and the
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fourth quartiles (p < .0001). The prevalence of major depression within the highest quartile for
experiencing the least job strain (5.6%).
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job strain are 16.0%, almost three times higher than depression rates in the quartile of nurses
Logistic regression was used to estimate the likelihood of having experienced a major depressive episode based on the work environment factors while controlling for established risk factors for depression. The overall model was significant (F = 26.67, p < .0001) although the
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combination of predictors only accounted for 9% of the variance in the presence or absence of major depression (see Table 3). Age, chronic conditions, and marital status remained significant predictors of depression. Nurses who were divorced or widowed were 1.8 times more likely to
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have a major depressive episode compared to married or single women. The presence of a chronic medical condition was the strongest overall predictor (OR = 3.4).
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Job strain maintained a strong relationship to depression, with higher levels of job strain
associated with a greater likelihood of major depression. The autonomy scale also showed a significant relationship to depression, with lower rates of autonomy predicting higher rates of depression. Greater control over practice was associated with lower risk of depression (p < .0001), but schedule flexibility was no longer a significant predictor. Work setting (hospital
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versus other) continued to maintain a significant relationship with depression, with hospitalbased nurses being at a lower risk. Using the same predictors, a linear regression model was run with the log of illness-
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related work absences as the dependent variable (Table 3). The combination of predictors
accounted for a similar proportion of variance in work absences as the depression model (F = 49.73, p < .0001; R2 = .08). As with major depression, age and chronic condition significantly
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predicted work absences. Job strain, autonomy, and control over practice were also significant predictors of work absences (p < .001). A one unit increase in the NWI-R autonomy scale
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decreases time absent by a factor of 0.97 and a unit increase in schedule flexibility decreases time absent by a factor of 0.92. In contrast to the model predicting major depression, greater schedule flexibility was significantly associated with fewer work absences. Hospital nurses also had more work absences. Nurses who worked evenings and nights were more likely to be absent
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from work.
Discussion
The overall 12-month prevalence of major depression in female nurses was 9.3% or
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nearly twice the prevalence in Canadian women in research conducted during the same time period {Patten, 2006 5609 /id}. Consistent with previous research, the prevalence of major
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depression was higher in nurses who were younger, divorced or widowed, and reported at least one chronic medical condition. Comparable rates of depression were found in LPNs and RN/RPNs however, professional group emerged as a modest but significant determinant of depression in the regression model. Days absent for illness were significantly higher in LPNs compared to RN/RPNs in both univariate testing and in the presence of other predictors in the regression modeling.
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The present results confirm a strong relationship between several work environment factors and major depression in nurses. Among the work environment factors examined, job strain had the strongest impact on both major depression and absenteeism. The relationship
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between the JSR and prevalence of depression in nurses is best described as curvilinear with no significant difference in prevalence at the lowest quartiles. However, when job strain exceeds the 50th percentile, the impact on depression is very apparent. In particular, there was a large and
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significant difference in depression prevalence between the third and fourth quartiles. Using the identical measures, Wang and colleagues also found a robust relationship between job strain and
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major depression within a randomly selected sample of Canadian working women {Wang, 2012 5717 /id}. Wang et al.’s findings differed, however, in two ways. First, the lowest rate of depression in women was observed in the second quartile of job strain suggesting that a mild degree of work stress may have protective benefits. Wang et al. also found no significant
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difference in depression prevalence for women in the third and fourth quartiles of job strain. In the present study, nurses appear to be more vulnerable to declining mental health as job strain increases. Even at the upper quartile of the JSR scores, the prevalence of major depression was
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only 6% in the Wang et al. sample of working women compared to 16% in nurses. Our analysis of autonomy produced some mixed findings but generally confirm our
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original hypothesis that greater workplace autonomy is associated with lower prevalence of depression and fewer work absences. Both the autonomy and control over practice scales from the NWI-R were significant determinants of depression and work absences after controlling for other influences including job strain. Prior research demonstrated a strong relationship between high autonomy and greater work satisfaction in nurses {Finn, 2001 5709 /id}. The present study shows that high autonomy is also associated with less depression and work absences. Control
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over practice as measured by the NWI-R assesses a different but related dimension of autonomy. Higher ratings on this scale are reported by nurses who felt their skills were fully utilized to provide quality patient care. Like autonomy, higher control over practice was associated with
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reduced prevalence of major depression and absenteeism. Having control over one’s schedule had no impact on depression but was associated with better work attendance. Schedule
flexibility remained a strong determinant of absenteeism even with chronic conditions in the
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model suggesting missed work was not solely due to ongoing medical problems. This finding supports a proposal from the nursing profession to allow nurses to self-schedule their shifts, a
absences {Dechant, 1990 5720 /id}.
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practice predicted to increase staff satisfaction, improve staff retention and lead to fewer work
General conditions of employment had little impact on the prevalence of depression with the exception of work setting. Contrary to our prediction, the prevalence of major depression in
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hospital-based nurses was lower than nurses working in other settings. Healthcare setting was significantly associated with depression even after controlling for other variables including job strain and chronic conditions. The fact that work setting was not associated with work absences
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also suggests its relationship to depression is not simply due to hospital workers having greater exposure to illness. The lower risk in hospital nurses could due to personal hardiness and self-
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selection to this work environment. Nurses with higher levels of hardiness may choose to work in hospitals where the work pace and complexity of patients is greater than other settings. Research has shown that individuals with higher levels of personal hardiness are less likely to be diagnosed with major depression {Maddi, 2006 5704 /id;Clark, 2002 5698 /id}. Nurses with lower levels of hardiness may gravitate to other health care settings. It is noteworthy that the
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overall prevalence of depression in non-hospital nurses was still substantially higher than the female working population {Gilmour, 2007 5715 /id}. Among the risk factors studied, the presence of one or more chronic conditions had the
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strongest influence on both depression and absenteeism. Seventy-three percent of nurses
reported having at least one chronic condition, a rate that is higher than the general Canadian population reported from surveys using the identical list of chronic condition {Patten, 2005 5718
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/id}. Nurses may have a higher rate due to the workforce being older (over 50% are over 45 years old), exposure to illness, and the physically demanding nature of the work. Both RNs and
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LPNs are often called upon to lift patients or equipment, subjecting them to musculoskeletal injuries. The likelihood of injury can be reduced by the use of lifting aids yet 36% of nurses in the NSWHN who were required to lift or transfer patients indicated that the necessary equipment was frequently unavailable {Shields, 2006 5721 /id}.
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As a secondary analysis of cross-sectional data, our study has some obvious limitations deserving acknowledgement. Foremost, we cannot establish a causal link between work environment and depression although compelling evidence that work environment factors do
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predict future major depression has emerged in a recent longitudinal study by our research team. Over a one year interval, both higher job strain and greater work-to-family conflict predicted
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future onset of major depression in working women {Wang, 2012 5717 /id}. Longitudinal research in other countries has produced similar finding. In an earlier review, the relative risk ratio of developing depression when exposed to high job stress was found to be approximately 2.0 across studies {Netterstrom, 2008 5745 /id}. Nonetheless, we need to consider alternative hypotheses to explain the nature of the relationships shown in our cross-sectional data. For example, it is possible that nurses with chronic depression self-select positions with lower
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autonomy and less flexibility in working conditions. Depressed nurses may also have job performance issues, leading them to migrate toward positions with less independence or authority to make decisions.
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All workplace factor measures used were based on self-report and there was no
independent verification of levels of job strain, autonomy, and control over practice. It is
possible that the relationship between some of the variables and depression is influenced by a
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negative outlook, where depressed nurses perceive their work environment as more stressful than non-depressed nurses. This is an often cited limitation of studies on workplace and psychosocial
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factors in which both the exposure (work environment) and outcome (depression) are assessed using self-report {Netterstrom, 2008 5745 /id}. We attempted to compensate for this limitation, referred to as the common method bias, by including a less subjective outcome measure, number illness-related absences, in addition to self-reported depression.
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The use of a structured diagnostic interview to identify cases of clinically significant depression is a notable strength of the NSWHN. Prior studies on depression in nurses have relied on self-administered symptom scales such as the CESD. We acknowledge that the
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NSWHN version of the CIDI was an older interview schedule that uses DSM III-R criteria. However, the criteria of the DSM-III and DSM-IV are relatively similar to each other, and there
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is strong evidence that the CIDI is able to successfully diagnose DSM-IV depression {Kurdyak, 2005 5695 /id}. Furthermore, because the criteria for a MDE did not change in the DSM 5 {American Psychiatric Association, 2013 5747 /id}, we can conclude the CIDI-derived classification of major depression is also consistent with the latest edition of the DSM. Finally, the data were collected in 2005-2006. Despite the survey results being almost a decade old, there is no clear indication that the work environment for nurses has markedly improved. In fact,
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some scholars feel that job strain is getting worse for nurses in many countries as healthcare budgets are reduced and patient volumes are increasing {Buchan, 2013 5742 /id}. Furthermore, the general aging trend in the population is having a negative effect on the nursing workforce.
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Experienced nurses are retiring and the recruitment of new nurses into the profession is not keeping pace with the population growth resulting in additional strain on the remaining
workforce. In addition to workload, lack of autonomy and feelings of disempowerment are
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factors associated with nursing turnover {Hayes, 2012 5743 /id}.
Future research is warranted to inform and extend the results of this study. The finding
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that hospital-based nurses have less depression requires replication. The role of hardiness and other protective factors should be explored in the same study. It would also be important to determine if the overall results, in particular the role of autonomy in depression prevalence, would be replicated in a large sample of male nurses. The strongest evidence of causation would
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come from a longitudinal study. We have conducted such as a study on a sample from the general working population in Alberta {Wang, 2012 5717 /id}. Unfortunately, the sample of health care workers is too small for a meaningful analysis of work environment predicting future
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depression. A longitudinal study focused on new graduates from nursing would provide
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invaluable data on the role of work environment on future mental health.
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Table 1 Sample characteristics and workplace factors (N = 17,437) Weighted %
95% Confidence Interval
Age Group
Position RN/RPN LPN
Full-time Part-time Shift work
74.88 12.18 1.81 10.88
73.86 11.40 1.50 10.15
-
21.39 28.29 35.52 18.83
-
75.90 12.96 2.12 11.61
56.47 43.52
55.33 42.38
-
57.61 44.66
79.16 19.56
78.47 18.87
-
79.85 20.25
59.02 38.70
-
61.30 40.98
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Hours
19.43 26.17 33.28 17.07
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Marital status Married/common-law Single Widowed Separated/divorced Work setting Hospital Other
20.41 27.23 34.40 17.95
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