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Perspectives in Psychiatric Care
ISSN 0031-5990
Quality of Life in Older Patients With Chronic Obstructive Pulmonary Disease (COPD) in Hong Kong: A Case-Control Study Yu-Tao Xiang, MD, PhD,* Tak-Shun Wong, MRCPsy,* Joshua Tsoh, FRCPsy,* Gabor S. Ungvari, MD, PhD, Christoph U. Correll, MD, Jitender Sareen, MD, Kirsten Penner-Goeke, MD, Fanny W.S. Ko, MD, FHKAM(Med), David S.C. Hui, FRCP, FCCP, and Helen F.K. Chiu, FRCPsy Yu-Tao Xiang, MD, PhD, is a Research Assistant Professor, Department of Psychiatry, Chinese University of Hong Kong, Hong Kong SAR, China and Faculty of Health Sciences, University of Macau, Macao SAR, China; Tak-Shun Wong, MRCPsy, is an Associate Consultant Psychiatrist, Department of Psychiatry, Chinese University of Hong Kong, Hong Kong SAR, China; Joshua Tsoh, FRCPsy, is a Consultant Psychiatrist, Department of Psychiatry, Chinese University of Hong Kong, Hong Kong SAR, China; Gabor S. Ungvari, MD, PhD, is a Professor, School of Psychiatry and Clinical Neurosciences, University of Western Australia, Perth, Western Australia, Australia and The University of Notre Dame Australia/Marian Centre, Perth, Western Australia, Australia; Christoph U. Correll, MD, is a Professor, Division of Psychiatry Research, The Zucker Hillside Hospital, North Shore-Long Island Jewish Health System, Glen Oaks, New York, USA; Jitender Sareen, MD, is a Professor, Department of Psychiatry, University of Manitoba Faculty of Medicine, Winnipeg, Canada; Kirsten Penner-Goeke, MD, is a Medical Student, Department of Psychiatry, University of Manitoba Faculty of Medicine, Winnipeg, Canada; Fanny W.S. Ko, MD, FHKAM(Med), is an Associate Consultant, Department of Medicine and Therapeutics, Chinese University of Hong Kong, Hong Kong, China; David S.C. Hui, FRCP, FCCP, is a Professor, Department of Medicine and Therapeutics, Chinese University of Hong Kong, Hong Kong, China; and Helen F.K. Chiu, FRCPsy, is a Professor, Department of Psychiatry, Chinese University of Hong Kong, Hong Kong SAR, China
Search terms: Chronic obstructive pulmonary disease, depression, elderly, outpatient, quality of life Author contact: [email protected], with a copy to the Editor: [email protected] Conflict of Interest Statement Dr. Correll has been a consultant and/or advisor to or has received honoraria from: Actelion, Alexza; American Academy of Child and Adolescent Psychiatry, Bristol-Myers Squibb, Cephalon, Eli Lilly, Genentech, Gerson Lehrman Group, IntraCellular Therapies, Lundbeck, Medavante, Medscape, Merck, National Institute of Mental Health, Janssen/J&J, Otsuka, Pfizer, ProPhase, Roche, Sunovion, Takeda, Teva, and Vanda. He has received grant support from BMS, Feinstein Institute for Medical Research, Janssen/J&J, National Institute of Mental Health (NIMH), National Alliance for Research in Schizophrenia and Depression (NARSAD), and Otsuka. He has been a Data Safety Monitoring Board member for Cephalon, Eli Lilly, Janssen, Lundbeck, Pfizer, Takeda, and Teva. The remaining authors had no conflicts of interest in conducting this study or preparing the manuscript.
PURPOSE: To date, there have been few studies examining quality of life (QOL) in older patients with chronic obstructive pulmonary disease (COPD) in China. The aim of the study was to assess QOL in Chinese older patients with COPD and explore its demographic and clinical correlates. DESIGN AND METHODS: Case-control study of 142 outpatients with COPD and 218 matched control subjects without COPD. COPD patients were recruited from a prospective study sample hospitalized in Hong Kong for acute COPD exacerbation (≥ 2 major COPD symptoms or > 1 major + minor COPD symptoms for ≥ 2 consecutive days). Controls were recruited from social centers in Hong Kong. Activity of daily living was assessed with the Instrumental Activities of Daily Living Scale (IADL), life events were evaluated with the Life Event Scale, depressive disorders were diagnosed using the Geriatric Depression Scale (GDS), and QOL was measured using the Medical Outcomes Study Short Form-12 (SF-12) and St. George’s Respiratory Questionnaire (SGRQ). FINDINGS: Compared to controls, patients had significantly lower scores in the physical (PCS score), but not in the mental (MCS score) QOL domain. Multivariate analyses showed that more hospitalizations in the past year significantly contributed to higher PCS score (p = .03), while higher GDS total score contributed to lower MCS score (p = .003). Severe and very severe COPD, more physical illnesses, and higher IADL total score each independently contributed to higher SGRQ total score, explaining 40.0% of the variance (p < .001). PRACTICE IMPLICATIONS: Our results suggest that therapeutic and psychosocial interventions alleviating depressive symptoms, severe COPD, comorbidities, and improving IADL in Chinese patients with COPD are likely of considerable benefit for improving QOL in patients with COPD.
*The authors equally contributed to this work. First Received January 17, 2014; Final Revision received April 1, 2014; Accepted for publication April 29, 2014. doi: 10.1111/ppc.12073
Perspectives in Psychiatric Care 51 (2015) 121–127 © 2014 Wiley Periodicals, Inc.
121
Quality of Life in Older Patients With Chronic Obstructive Pulmonary Disease (COPD) in Hong Kong: A Case-Control Study
Chronic obstructive pulmonary disease (COPD) is a common and preventable disease characterized by persistent airflow limitation (Global Initiative for Chronic Obstructive Lung Disease, 2013). The clinical presentations of COPD include intermittent exacerbations of chronic dyspnea, cough, and sputum production, and its progressive course may disturb various aspects of the patients’ life. COPD is a common cause of disability and even mild COPD seems to lower patients’ quality of life (QOL) (Miravitlles et al., 2004). Nowadays, cure is still impossible for most COPD patients; therefore, improving patients’ QOL has become a major goal of treatment and care. In past decades, QOL has been increasingly used as an outcome to evaluate the effectiveness of treatment for COPD (Stahl et al., 2005). Though definitions of QOL vary, we defined QOL as “an individual’s perception of one’s position in life in relation to goals, expectations, standards and concerns in the context of the culture and value systems in which one lives” (World Health Organization, 1998). Understanding the association of socio-demographic and clinical correlates with QOL can facilitate the design of optimal clinical interventions. Most studies examining QOL in COPD have been conducted in Western countries, and found that a host of demographic and clinical factors, such as COPD severity, depression, anxiety, poor health status, impaired cognitive function, and poor social support, were associated with lower QOL (Cully et al., 2006; Engstrom, Persson, Larsson, & Sullivan, 2001; Miravitlles et al., 2004; Peruzza et al., 2003). Preliminary evidence suggests that ethnic and cultural differences influence QOL (Xiang, Chiu, & Ungvari, 2010). Thus, these prior findings may not be entirely applicable to non-Western sociocultural environments. The aim of this study was to examine QOL in Chinese patients with COPD aged 60 years and above based in a casecontrol design and to explore its demographic and clinical correlates. Methods Study Setting and Participants This study was part of an ongoing project entitled “Acute Exacerbation of Chronic Obstructive Pulmonary Disease (AECOPD)” (Ko et al., 2007) that follows patients admitted to the medical wards of Prince of Wales Hospital (PWH) in Hong Kong with acute exacerbation of COPD from May 1, 2004, to April 30, 2005. Study participants had preexisting COPD and at least two of the major COPD symptoms (increased dyspnea, increased sputum purulence, increased sputum amount), or one major and one minor symptoms (nasal discharge/congestion, wheezing, sore throat, cough) for at least 2 consecutive days. Patients were recruited if they were of Chinese ethnicity, able to communicate, able to toler122
ate a 1-hr interview, and able to understand the purpose and procedures of the study. Approval for the study was obtained from the Joint Chinese University of Hong Kong—New Territories East Cluster Clinical Research Ethics committee. All subjects provided written consent to participate to this study. For the current study, patients with COPD were recruited consecutively after hospital discharge from the PWH Respiratory Outpatient Clinic. Control subjects with no history of COPD matched to age and sex were recruited on a convenience basis from social centers in the Shatin and Tai Po districts of Hong Kong. Data Collection Each patient with COPD or control subject received a face-toface interview by one of two trained psychiatrists. Sociodemographic data were collected using a form specifically designed for this study. The GOLD (Global Initiative for Chronic Obstructive Lung Disease) guideline was used to classify the severity of COPD (National Institutes of Health, National Heart, Lung, and Blood Institute, 2003): (a) stage 1 mild COPD: FEV1 ≥ 80% of predicted value; (b) stage 2 moderate COPD: FEV1 ≥ 50% and < 80% of predicted value; (c) stage 3 severe COPD: FEV1 ≥ 30% and < 50% of predicted value; and (d) stage 4 very severe COPD: FEV1 < 30% of predicted value. The number of hospital admissions in the past year was recorded from the patients’ medical records. Assessment of the activities of daily living (ADL) was measured with the locally adapted Instrumental Activities of Daily Living Scale (IADL) (Lawton & Brody, 1969). IADL covers use of telephone, shopping, cooking, laundry, use of public transportation, medication, and financial management. In the local version of the IADL, each of these activities was rated on a four-point scale ranging from 0 to 3. A higher total score indicates more advanced functional disability. Life events were measured using a modified version of the Life Event Scale (LES) (Paykel, Prusoff, & Uhlenhuth, 1971). This Chinese scale has been used extensively in the Chinese population (Chiu et al., 1999). The participants were asked whether they had experienced significant life events in the past year. The validated Cantonese version of the Mini-Mental State Examination (MMSE) (Chiu, Lee, Chung, & Kwong, 1994; Folstein, Folstein, & McHugh, 1975) was administered to screen for cognitive impairment, with lower scores indicating more severe cognitive dysfunction. Depressive symptoms were evaluated using the validated Chinese version of the 15-item Geriatric Depression Scale (GDS), with higher scores reflecting more severe depressive symptoms (Lee, Chiu, & Kwong, 1994; Yesavage et al., 1982). Participants’ QOL was measured with the validated Chinese version of Medical Outcomes Study Short Form-12 Perspectives in Psychiatric Care 51 (2015) 121–127 © 2014 Wiley Periodicals, Inc.
Quality of Life in Older Patients With Chronic Obstructive Pulmonary Disease (COPD) in Hong Kong: A Case-Control Study
(SF-12) and the St. George’s Respiratory Questionnaire (SGRQ) (Chan et al., 2002; Jones, Quirk, Baveystock, & Littlejohns, 1992; Ware, Kosinski, Turner-Bowker, & Gandek, 2005). The SF-12 is a generic instrument of QOL containing 12 items. The SF-12 has two domains: physical component score (PCS) and a mental component score (MCS), with higher scores indicating better QOL. The SGRQ is a diseasespecific QOL measure for respiratory diseases that consists of 50 items (76 responses) covering three domains: symptoms (frequency and severity), activity (activities that cause or are limited by breathlessness), and impact (social functioning, psychological disturbances resulting from airway disease). The total score was used in this study. Higher scores indicate worse QOL. Two trained psychiatrists were involved in this study. The inter-rater reliabilities of the above instruments in 60 older psychiatric patients were satisfactory (intra-class correlation coefficients > 0.9). Statistical Analyses The data were analyzed with SPSS 20.0 for Windows (SPSS Inc., Chicago, IL, USA). Comparisons between COPD patients and controls with regard to socio-demographic characteristics and the PCS and MCS were performed using independent sample t tests, Mann–Whitney U tests, and chisquare tests, as appropriate, and then PCS and MCS between the two groups were compared using analysis of covariance (ANCOVA) after controlling for variables that differed significantly between the two groups. Associations of the PCS, MCS, and SGRQ with socio-demographic and clinical characteristics in patients were analyzed using Spearman’s rank correlation analysis. Stepwise multiple linear regression analyses were used to identify factors that were independently associated with performance on the PCS, MCS, and SGRQ in COPD patients. In the regression analyses, the PCS, MCS, and SGRQ scores were entered as the dependent variables separately, and all variables that showed significant correlations with PCS, MCS, or SGRQ in univariate analyses were entered as independent variables. The normality of distributions for the continuous variables was checked with the one-sample Kolmogorov–Smirnov test. Two-tailed tests were used in all analyses with the significance level set at .05. Results A total of 154 COPD patients and 225 controls were approached and invited to participate in this study. Finally, 142 COPD patients and 218 controls met study criteria, agreed to participate, and completed the assessments. Table 1 shows the basic demographic variables and QOL in both groups, and the patients’ clinical characteristics. The patients’ score on the PCS was significantly lower than that of Perspectives in Psychiatric Care 51 (2015) 121–127 © 2014 Wiley Periodicals, Inc.
the controls (p < .001), while there was no difference between the two groups in the MCS (p = .59). After controlling for variables that differed significantly between the two groups, including religious belief, number of physical illness and hospitalization in the past year, and IADL, the significant difference between the two groups with respect to the PCS (F(1,353) = 20.2, p < .001) remained, but there was still no difference in the MCS EBPM (F(1,353) = 0.1, p = .76). Table 2 presents the relationships between QOL and sociodemographic and clinical variables. In the patient group, higher PCS was significantly associated with younger age and lower IADL total score, while higher MCS was associated with less hospitalization in the past year and lower GDS total scores. Higher SGRQ total score was significantly associated with more severe COPD, more physical illnesses and hospitalization in the past year, and higher IADL and GDS total score. Table 3 shows the independent correlates of the PCS, MCS, and SGRQ. More hospitalization in the past year significantly contributed to higher PCS score (p = .03), accounting for 7% of the variance, while higher GDS total score contributed to lower MCS score (p = .003), accounting for 11% of the variance. Severe and very severe COPD, more physical illnesses, and higher IADL total score significantly contributed to higher SGRQ total score (p < .001), accounting for 40% of the variance. Discussion To the best of our knowledge, this is the first study exploring the impact of COPD on QOL in Chinese older patients based on a case-control design. The finding that COPD patients had significantly poorer scores in physical QOL domain compared to the controls is consistent with results of Western samples (Peruzza et al., 2003). According to the distress/ protection QOL model (Voruganti, Heslegrave, Awad, & Seeman, 1998), QOL results from an interaction between several protective factors (e.g., self-esteem and social support) and distressing factors (e.g., major physical diseases). Due to the disease nature, COPD patients experience much restriction in daily activities and social activities, especially for those with severe and very severe COPD (78.2% of the current sample) because they often require long-term oxygen therapy. These distressing factors lead to decreasing physical QOL. Contrary to our expectation, however, patients did not differ from the controls regarding psychological QOL. As a complex concept, QOL is not only affected by medical conditions but also by value systems and philosophical and cultural dimensions (Hyland, 1997). One possible explanation for this finding is that the majority of patients (86.6%) lived with their families. We speculate that social support received from family members may explain the patients’ relatively good psychological QOL. In Western countries, the majority of population is strongly influenced by the Judeo123
Quality of Life in Older Patients With Chronic Obstructive Pulmonary Disease (COPD) in Hong Kong: A Case-Control Study
Table 1. Basic Demographic and Clinical Characteristics of the Study ample
Male Married/cohabitating Living with others Education Illiterate or primary school Junior and senior high school College and above Religious belief Financial perception Bad Moderate Good COPD severity Mild (FEV1 ≥ 80% predicted normal) Moderate (FEV1 50–80% predicted normal) Severe(FEV1 30–50% predicted normal) Very severe (FEV1 < 30% predicted normal)
The whole sample (N = 360)
Controls (N = 218)
COPD patients (N = 142)
Statistics
n
%
n
%
n
%
χ2
282 261 300
78.3 72.5 83.3
164 155 177
75.2 71.1 81.2
118 106 123
83.1 74.6 86.6
253 92 15 198
70.3 25.6 4.2 55.0
147 58 13 136
67.4 26.6 6.0 62.4
106 34 2 62
74.6 23.9 1.4 43.7
99 98 163
27.5 27.2 45.3
75 54 89
34.4 24.8 40.8
24 44 74
16.9 31.0 52.1
9 22 65 46
2.5 6.1 18.1 12.8
— — — —
— — — —
9 22 65 46
6.3 15.5 45.8 32.4
SD
M
SD
6.6 3.8 1.5 0.5 5.7 .977 3.6 20.6 18.5 19.8
75.0 26.5 1.9 0.2 3.2 0.7 2.8 — 50.4 57.6
6.9 3.5 1.3 0.4 5.4 1.1 3.1 — 16.0 16.7
M Age (year) MMSE total No. of physical illnesses No. of hospitalization in the past year IADL total Life events in the past year GDS SGRQ total PCS MCS
74.6 26.3 2.3 0.4 4.3 .56 3.5 46.4 45.8 57.1
M 73.9 26.0 3.0 0.7 5.8 0.4 4.7 46.4 38.7 56.4
df
p
3.1 0.5 1.8 5.2
1 1 1 2
.08 .46 .18 .08
12.8 13.2
1 2
< .001 .001
SD
T/Z
df
p
6.2 4.2 1.7 0.5 5.7 0.7 4.1 20.6 20.0 23.9
1.5 1.3 −5.5 −8.3 −6.0 −1.7 −4.8
358 358 —a —a —a —a —a
Perspectives in Psychiatric Care
ISSN 0031-5990
Quality of Life in Older Patients With Chronic Obstructive Pulmonary Disease (COPD) in Hong Kong: A Case-Control Study Yu-Tao Xiang, MD, PhD,* Tak-Shun Wong, MRCPsy,* Joshua Tsoh, FRCPsy,* Gabor S. Ungvari, MD, PhD, Christoph U. Correll, MD, Jitender Sareen, MD, Kirsten Penner-Goeke, MD, Fanny W.S. Ko, MD, FHKAM(Med), David S.C. Hui, FRCP, FCCP, and Helen F.K. Chiu, FRCPsy Yu-Tao Xiang, MD, PhD, is a Research Assistant Professor, Department of Psychiatry, Chinese University of Hong Kong, Hong Kong SAR, China and Faculty of Health Sciences, University of Macau, Macao SAR, China; Tak-Shun Wong, MRCPsy, is an Associate Consultant Psychiatrist, Department of Psychiatry, Chinese University of Hong Kong, Hong Kong SAR, China; Joshua Tsoh, FRCPsy, is a Consultant Psychiatrist, Department of Psychiatry, Chinese University of Hong Kong, Hong Kong SAR, China; Gabor S. Ungvari, MD, PhD, is a Professor, School of Psychiatry and Clinical Neurosciences, University of Western Australia, Perth, Western Australia, Australia and The University of Notre Dame Australia/Marian Centre, Perth, Western Australia, Australia; Christoph U. Correll, MD, is a Professor, Division of Psychiatry Research, The Zucker Hillside Hospital, North Shore-Long Island Jewish Health System, Glen Oaks, New York, USA; Jitender Sareen, MD, is a Professor, Department of Psychiatry, University of Manitoba Faculty of Medicine, Winnipeg, Canada; Kirsten Penner-Goeke, MD, is a Medical Student, Department of Psychiatry, University of Manitoba Faculty of Medicine, Winnipeg, Canada; Fanny W.S. Ko, MD, FHKAM(Med), is an Associate Consultant, Department of Medicine and Therapeutics, Chinese University of Hong Kong, Hong Kong, China; David S.C. Hui, FRCP, FCCP, is a Professor, Department of Medicine and Therapeutics, Chinese University of Hong Kong, Hong Kong, China; and Helen F.K. Chiu, FRCPsy, is a Professor, Department of Psychiatry, Chinese University of Hong Kong, Hong Kong SAR, China
Search terms: Chronic obstructive pulmonary disease, depression, elderly, outpatient, quality of life Author contact: [email protected], with a copy to the Editor: [email protected] Conflict of Interest Statement Dr. Correll has been a consultant and/or advisor to or has received honoraria from: Actelion, Alexza; American Academy of Child and Adolescent Psychiatry, Bristol-Myers Squibb, Cephalon, Eli Lilly, Genentech, Gerson Lehrman Group, IntraCellular Therapies, Lundbeck, Medavante, Medscape, Merck, National Institute of Mental Health, Janssen/J&J, Otsuka, Pfizer, ProPhase, Roche, Sunovion, Takeda, Teva, and Vanda. He has received grant support from BMS, Feinstein Institute for Medical Research, Janssen/J&J, National Institute of Mental Health (NIMH), National Alliance for Research in Schizophrenia and Depression (NARSAD), and Otsuka. He has been a Data Safety Monitoring Board member for Cephalon, Eli Lilly, Janssen, Lundbeck, Pfizer, Takeda, and Teva. The remaining authors had no conflicts of interest in conducting this study or preparing the manuscript.
PURPOSE: To date, there have been few studies examining quality of life (QOL) in older patients with chronic obstructive pulmonary disease (COPD) in China. The aim of the study was to assess QOL in Chinese older patients with COPD and explore its demographic and clinical correlates. DESIGN AND METHODS: Case-control study of 142 outpatients with COPD and 218 matched control subjects without COPD. COPD patients were recruited from a prospective study sample hospitalized in Hong Kong for acute COPD exacerbation (≥ 2 major COPD symptoms or > 1 major + minor COPD symptoms for ≥ 2 consecutive days). Controls were recruited from social centers in Hong Kong. Activity of daily living was assessed with the Instrumental Activities of Daily Living Scale (IADL), life events were evaluated with the Life Event Scale, depressive disorders were diagnosed using the Geriatric Depression Scale (GDS), and QOL was measured using the Medical Outcomes Study Short Form-12 (SF-12) and St. George’s Respiratory Questionnaire (SGRQ). FINDINGS: Compared to controls, patients had significantly lower scores in the physical (PCS score), but not in the mental (MCS score) QOL domain. Multivariate analyses showed that more hospitalizations in the past year significantly contributed to higher PCS score (p = .03), while higher GDS total score contributed to lower MCS score (p = .003). Severe and very severe COPD, more physical illnesses, and higher IADL total score each independently contributed to higher SGRQ total score, explaining 40.0% of the variance (p < .001). PRACTICE IMPLICATIONS: Our results suggest that therapeutic and psychosocial interventions alleviating depressive symptoms, severe COPD, comorbidities, and improving IADL in Chinese patients with COPD are likely of considerable benefit for improving QOL in patients with COPD.
*The authors equally contributed to this work. First Received January 17, 2014; Final Revision received April 1, 2014; Accepted for publication April 29, 2014. doi: 10.1111/ppc.12073
Perspectives in Psychiatric Care 51 (2015) 121–127 © 2014 Wiley Periodicals, Inc.
121
Quality of Life in Older Patients With Chronic Obstructive Pulmonary Disease (COPD) in Hong Kong: A Case-Control Study
Chronic obstructive pulmonary disease (COPD) is a common and preventable disease characterized by persistent airflow limitation (Global Initiative for Chronic Obstructive Lung Disease, 2013). The clinical presentations of COPD include intermittent exacerbations of chronic dyspnea, cough, and sputum production, and its progressive course may disturb various aspects of the patients’ life. COPD is a common cause of disability and even mild COPD seems to lower patients’ quality of life (QOL) (Miravitlles et al., 2004). Nowadays, cure is still impossible for most COPD patients; therefore, improving patients’ QOL has become a major goal of treatment and care. In past decades, QOL has been increasingly used as an outcome to evaluate the effectiveness of treatment for COPD (Stahl et al., 2005). Though definitions of QOL vary, we defined QOL as “an individual’s perception of one’s position in life in relation to goals, expectations, standards and concerns in the context of the culture and value systems in which one lives” (World Health Organization, 1998). Understanding the association of socio-demographic and clinical correlates with QOL can facilitate the design of optimal clinical interventions. Most studies examining QOL in COPD have been conducted in Western countries, and found that a host of demographic and clinical factors, such as COPD severity, depression, anxiety, poor health status, impaired cognitive function, and poor social support, were associated with lower QOL (Cully et al., 2006; Engstrom, Persson, Larsson, & Sullivan, 2001; Miravitlles et al., 2004; Peruzza et al., 2003). Preliminary evidence suggests that ethnic and cultural differences influence QOL (Xiang, Chiu, & Ungvari, 2010). Thus, these prior findings may not be entirely applicable to non-Western sociocultural environments. The aim of this study was to examine QOL in Chinese patients with COPD aged 60 years and above based in a casecontrol design and to explore its demographic and clinical correlates. Methods Study Setting and Participants This study was part of an ongoing project entitled “Acute Exacerbation of Chronic Obstructive Pulmonary Disease (AECOPD)” (Ko et al., 2007) that follows patients admitted to the medical wards of Prince of Wales Hospital (PWH) in Hong Kong with acute exacerbation of COPD from May 1, 2004, to April 30, 2005. Study participants had preexisting COPD and at least two of the major COPD symptoms (increased dyspnea, increased sputum purulence, increased sputum amount), or one major and one minor symptoms (nasal discharge/congestion, wheezing, sore throat, cough) for at least 2 consecutive days. Patients were recruited if they were of Chinese ethnicity, able to communicate, able to toler122
ate a 1-hr interview, and able to understand the purpose and procedures of the study. Approval for the study was obtained from the Joint Chinese University of Hong Kong—New Territories East Cluster Clinical Research Ethics committee. All subjects provided written consent to participate to this study. For the current study, patients with COPD were recruited consecutively after hospital discharge from the PWH Respiratory Outpatient Clinic. Control subjects with no history of COPD matched to age and sex were recruited on a convenience basis from social centers in the Shatin and Tai Po districts of Hong Kong. Data Collection Each patient with COPD or control subject received a face-toface interview by one of two trained psychiatrists. Sociodemographic data were collected using a form specifically designed for this study. The GOLD (Global Initiative for Chronic Obstructive Lung Disease) guideline was used to classify the severity of COPD (National Institutes of Health, National Heart, Lung, and Blood Institute, 2003): (a) stage 1 mild COPD: FEV1 ≥ 80% of predicted value; (b) stage 2 moderate COPD: FEV1 ≥ 50% and < 80% of predicted value; (c) stage 3 severe COPD: FEV1 ≥ 30% and < 50% of predicted value; and (d) stage 4 very severe COPD: FEV1 < 30% of predicted value. The number of hospital admissions in the past year was recorded from the patients’ medical records. Assessment of the activities of daily living (ADL) was measured with the locally adapted Instrumental Activities of Daily Living Scale (IADL) (Lawton & Brody, 1969). IADL covers use of telephone, shopping, cooking, laundry, use of public transportation, medication, and financial management. In the local version of the IADL, each of these activities was rated on a four-point scale ranging from 0 to 3. A higher total score indicates more advanced functional disability. Life events were measured using a modified version of the Life Event Scale (LES) (Paykel, Prusoff, & Uhlenhuth, 1971). This Chinese scale has been used extensively in the Chinese population (Chiu et al., 1999). The participants were asked whether they had experienced significant life events in the past year. The validated Cantonese version of the Mini-Mental State Examination (MMSE) (Chiu, Lee, Chung, & Kwong, 1994; Folstein, Folstein, & McHugh, 1975) was administered to screen for cognitive impairment, with lower scores indicating more severe cognitive dysfunction. Depressive symptoms were evaluated using the validated Chinese version of the 15-item Geriatric Depression Scale (GDS), with higher scores reflecting more severe depressive symptoms (Lee, Chiu, & Kwong, 1994; Yesavage et al., 1982). Participants’ QOL was measured with the validated Chinese version of Medical Outcomes Study Short Form-12 Perspectives in Psychiatric Care 51 (2015) 121–127 © 2014 Wiley Periodicals, Inc.
Quality of Life in Older Patients With Chronic Obstructive Pulmonary Disease (COPD) in Hong Kong: A Case-Control Study
(SF-12) and the St. George’s Respiratory Questionnaire (SGRQ) (Chan et al., 2002; Jones, Quirk, Baveystock, & Littlejohns, 1992; Ware, Kosinski, Turner-Bowker, & Gandek, 2005). The SF-12 is a generic instrument of QOL containing 12 items. The SF-12 has two domains: physical component score (PCS) and a mental component score (MCS), with higher scores indicating better QOL. The SGRQ is a diseasespecific QOL measure for respiratory diseases that consists of 50 items (76 responses) covering three domains: symptoms (frequency and severity), activity (activities that cause or are limited by breathlessness), and impact (social functioning, psychological disturbances resulting from airway disease). The total score was used in this study. Higher scores indicate worse QOL. Two trained psychiatrists were involved in this study. The inter-rater reliabilities of the above instruments in 60 older psychiatric patients were satisfactory (intra-class correlation coefficients > 0.9). Statistical Analyses The data were analyzed with SPSS 20.0 for Windows (SPSS Inc., Chicago, IL, USA). Comparisons between COPD patients and controls with regard to socio-demographic characteristics and the PCS and MCS were performed using independent sample t tests, Mann–Whitney U tests, and chisquare tests, as appropriate, and then PCS and MCS between the two groups were compared using analysis of covariance (ANCOVA) after controlling for variables that differed significantly between the two groups. Associations of the PCS, MCS, and SGRQ with socio-demographic and clinical characteristics in patients were analyzed using Spearman’s rank correlation analysis. Stepwise multiple linear regression analyses were used to identify factors that were independently associated with performance on the PCS, MCS, and SGRQ in COPD patients. In the regression analyses, the PCS, MCS, and SGRQ scores were entered as the dependent variables separately, and all variables that showed significant correlations with PCS, MCS, or SGRQ in univariate analyses were entered as independent variables. The normality of distributions for the continuous variables was checked with the one-sample Kolmogorov–Smirnov test. Two-tailed tests were used in all analyses with the significance level set at .05. Results A total of 154 COPD patients and 225 controls were approached and invited to participate in this study. Finally, 142 COPD patients and 218 controls met study criteria, agreed to participate, and completed the assessments. Table 1 shows the basic demographic variables and QOL in both groups, and the patients’ clinical characteristics. The patients’ score on the PCS was significantly lower than that of Perspectives in Psychiatric Care 51 (2015) 121–127 © 2014 Wiley Periodicals, Inc.
the controls (p < .001), while there was no difference between the two groups in the MCS (p = .59). After controlling for variables that differed significantly between the two groups, including religious belief, number of physical illness and hospitalization in the past year, and IADL, the significant difference between the two groups with respect to the PCS (F(1,353) = 20.2, p < .001) remained, but there was still no difference in the MCS EBPM (F(1,353) = 0.1, p = .76). Table 2 presents the relationships between QOL and sociodemographic and clinical variables. In the patient group, higher PCS was significantly associated with younger age and lower IADL total score, while higher MCS was associated with less hospitalization in the past year and lower GDS total scores. Higher SGRQ total score was significantly associated with more severe COPD, more physical illnesses and hospitalization in the past year, and higher IADL and GDS total score. Table 3 shows the independent correlates of the PCS, MCS, and SGRQ. More hospitalization in the past year significantly contributed to higher PCS score (p = .03), accounting for 7% of the variance, while higher GDS total score contributed to lower MCS score (p = .003), accounting for 11% of the variance. Severe and very severe COPD, more physical illnesses, and higher IADL total score significantly contributed to higher SGRQ total score (p < .001), accounting for 40% of the variance. Discussion To the best of our knowledge, this is the first study exploring the impact of COPD on QOL in Chinese older patients based on a case-control design. The finding that COPD patients had significantly poorer scores in physical QOL domain compared to the controls is consistent with results of Western samples (Peruzza et al., 2003). According to the distress/ protection QOL model (Voruganti, Heslegrave, Awad, & Seeman, 1998), QOL results from an interaction between several protective factors (e.g., self-esteem and social support) and distressing factors (e.g., major physical diseases). Due to the disease nature, COPD patients experience much restriction in daily activities and social activities, especially for those with severe and very severe COPD (78.2% of the current sample) because they often require long-term oxygen therapy. These distressing factors lead to decreasing physical QOL. Contrary to our expectation, however, patients did not differ from the controls regarding psychological QOL. As a complex concept, QOL is not only affected by medical conditions but also by value systems and philosophical and cultural dimensions (Hyland, 1997). One possible explanation for this finding is that the majority of patients (86.6%) lived with their families. We speculate that social support received from family members may explain the patients’ relatively good psychological QOL. In Western countries, the majority of population is strongly influenced by the Judeo123
Quality of Life in Older Patients With Chronic Obstructive Pulmonary Disease (COPD) in Hong Kong: A Case-Control Study
Table 1. Basic Demographic and Clinical Characteristics of the Study ample
Male Married/cohabitating Living with others Education Illiterate or primary school Junior and senior high school College and above Religious belief Financial perception Bad Moderate Good COPD severity Mild (FEV1 ≥ 80% predicted normal) Moderate (FEV1 50–80% predicted normal) Severe(FEV1 30–50% predicted normal) Very severe (FEV1 < 30% predicted normal)
The whole sample (N = 360)
Controls (N = 218)
COPD patients (N = 142)
Statistics
n
%
n
%
n
%
χ2
282 261 300
78.3 72.5 83.3
164 155 177
75.2 71.1 81.2
118 106 123
83.1 74.6 86.6
253 92 15 198
70.3 25.6 4.2 55.0
147 58 13 136
67.4 26.6 6.0 62.4
106 34 2 62
74.6 23.9 1.4 43.7
99 98 163
27.5 27.2 45.3
75 54 89
34.4 24.8 40.8
24 44 74
16.9 31.0 52.1
9 22 65 46
2.5 6.1 18.1 12.8
— — — —
— — — —
9 22 65 46
6.3 15.5 45.8 32.4
SD
M
SD
6.6 3.8 1.5 0.5 5.7 .977 3.6 20.6 18.5 19.8
75.0 26.5 1.9 0.2 3.2 0.7 2.8 — 50.4 57.6
6.9 3.5 1.3 0.4 5.4 1.1 3.1 — 16.0 16.7
M Age (year) MMSE total No. of physical illnesses No. of hospitalization in the past year IADL total Life events in the past year GDS SGRQ total PCS MCS
74.6 26.3 2.3 0.4 4.3 .56 3.5 46.4 45.8 57.1
M 73.9 26.0 3.0 0.7 5.8 0.4 4.7 46.4 38.7 56.4
df
p
3.1 0.5 1.8 5.2
1 1 1 2
.08 .46 .18 .08
12.8 13.2
1 2
< .001 .001
SD
T/Z
df
p
6.2 4.2 1.7 0.5 5.7 0.7 4.1 20.6 20.0 23.9
1.5 1.3 −5.5 −8.3 −6.0 −1.7 −4.8
358 358 —a —a —a —a —a
