Outcomes and health-related quality of life following hospitalization for an acute exacerbation of COPD

Blackwell Science, LtdOxford, UKRESRespirology1323-77992005 Blackwell Publishing Asia Pty LtdSeptember 2005103334340Original ArticleHospitalization and COPDQ Wang and J Bourbeau Respirology (2005) 10, 334 340 ORIGINAL ARTICLE Outcomes and health-related quality of life following hospitalization for an acute exacerbation of COPD Qiuyue WANG 1,2 AND Jean BOURBEAU 1 1 Respiratory Epidemiology Unit, McGill University, Montreal, Canada, and 2 Institute of Respiratory Disease, China Medical University, Shenyang, China Outcomes and health-related quality of life following hospitalization for an acute exacerbation of COPD WANG Q, BOURBEAU J. Respirology 2005; 10: 334 340 Objective: The purpose of this study was to understand the outcomes for patients admitted to hospital for an acute exacerbation of COPD, and to determine the factors influencing quality of life and health service utilization of patients with COPD. Methodology: Hospital outcomes of 282 patients with moderate and severe COPD, for an acute exacerbation, were retrospectively evaluated. After 24 months of follow up, health-related quality of life (QoL) and health service utilization (emergency room (ER) visit and readmission) in 54 patients admitted previously, were surveyed by questionnaires. Results: Of 282 COPD patients admitted for an acute exacerbation, 28 patients (9.9%) died during hospitalization, 241 patients (85.5%) were discharged home, and only 13 patients (4.6%) needed long-term care facilities. Although over 50% of the patients had survived over 2 years after discharge, their QoL was poor. Patients who frequently went to the ER or were admitted, were those with poor QoL, severe dyspnoea and frequent exacerbation. COPD exacerbation and dyspnoea were the main factors influencing QoL of the patients. Age, comorbidity, QoL, FEV 1, frequency of COPD exacerbation, long-term oxygen therapy, and family doctor were the factors determining the likelihood of patients visiting the ER. Frequency of COPD exacerbation, family doctor and living alone were the factors determining which patients were likely to be admitted to hospital. Conclusion: The outcomes and QoL of patients admitted for an acute exacerbation of COPD were poor. The major factors influencing QoL were frequency of COPD exacerbation and severity of dyspnoea. Improvement of social and medical networks (e.g. reducing the number of patients living alone and providing family doctors for patients) may reduce health care service utilization. Key words: chronic obstructive pulmonary disease, exacerbation, health-related quality of life, hospitalization. INTRODUCTION COPD is a leading cause of morbidity and mortality amongst the adult population worldwide. 1 It is the fourth most common cause of death in the world and affects 4 6% of people over 45 years of age. 2,3 All other major causes of death are declining, whereas COPD is Correspondence: Qiuyue Wang, Institute of Respiratory Disease, China Medical University, no. 155 Nanjing Northern Street, Heping District, Shenyang 110001, China. Email: qywang2002@hotmail.com Received 4 August 2004; accepted for publication 3 December 2004. the only leading disease that is increasing in prevalence and mortality and is probably the major cause of disability. 4,5 As cigarette smoking is now more prevalent among younger age groups, COPD will continue to remain a common disease. 6 As life expectancy increases, a greater prevalence of COPD and mortality from this disease are likely. In an era of increasing fiscal constraints, health care delivery practices have changed, especially those related to hospitalization. Nowadays, despite the high prevalence and mortality of COPD, very little is known about the outcomes of patients hospitalized with an acute exacerbation of COPD. Emphasis has been limited to hospital mortality rates with little attention being given to the health-related quality of life (HRQoL) and health-care service utilization following

Hospitalization and COPD 335 hospitalization. On average, COPD patients have one to four acute exacerbations per year and each time, the exacerbation may have important effects on HRQoL and patient outcomes. 7 COPD patients discharged from hospital after an acute exacerbation are known to be at substantial risk of readmission in the next year. 8 11 Patients with an acute exacerbation requiring hospitalization are first seen in the emergency room (ER). They are thought to be responsible for much of the ER workload during certain periods of the year. However, the factors determining ER visits and the long-term outcomes are still not clear. A better understanding of long-term outcomes of COPD patients following hospitalization, may help patients and their physicians to better manage the disease and in making health-care decisions. The purpose of the present study was to assess hospital outcomes, long-term outcomes after hospital discharge, and factors related to HRQoL, ER visits and readmission to hospital, in a sample of patients admitted for acute exacerbation of COPD. METHODS Study population This study was a three-centre study, conducted in two phases, in patients hospitalized for acute exacerbation of COPD. In phase I, the medical charts of 282 COPD patients, hospitalized in the respiratory wards of three affiliated hospitals of McGill University, Montreal, Canada, for an acute exacerbation over a 12- month period, were reviewed to establish baseline data on hospital care and outcomes. To be eligible for the study, the patients had to meet the following criteria: (i) aged 40 years; (ii) hospitalization for acute exacerbation of COPD; (iii) smoker or ex-smoker; (iv) FEV 1 <80% of predicted and FEV 1 /FVC <70% postbronchodilator, within 12 months prior to admission; and (v) have no other lung disease (including asthma) as a principal cause of pulmonary function limitation. The patient profiles based upon this initial evaluation are listed in Table 1. Table 1 Profiles of patients in phase I of the chronic obstructive pulmonary disease study (n = 282) Characteristics Findings Male/female (% male) 116/166 (41.1) Age (years) 71.2 ± 9.9 Smoking history (pack-years) 57.9 ± 26.4 Current smokers (%) 30.1 Comorbidity (score) 2.28 ± 1.69 FEV 1 (L) 0.92 ± 0.36 FEV 1 (% predicted) 35.9 ± 13.2 FEV 1 /FVC 0.45 ± 0.12 Oxygen therapy at home (%) 30.1 Values are mean ± SD, unless otherwise indicated. In phase II, of the 241 patients who were studied in phase I and discharged home, 156 patients were monitored. In total, 85 patients were not further reviewed because of changes of address and/or telephone number or because they refused. There were no significant differences between the 156 patients who were followed up and the 85 not-followed up, with respect to their baseline characteristics (P > 0.05). By the end of the follow-up period (2 1 / 2 years), 70 of the 156 patients had died, of whom 38 died in the first 12 months and 32 in the second 12 months of follow up. The cause of death was COPD exacerbation in 56 patients, lung cancer in four, cardiovascular disease in two, car accident in one, and was unknown in seven patients. Of the 86 patients who were alive and eligible to complete the questionnaire, 54 (33 male, 21 female), who had been followed for 23.5 ± 4.5 months (median, 24; range, 18.5 30), were enrolled and their socio-medical network, health service utilization and HRQoL were assessed by questionnaire. A total of 19 patients refused to participate further and 13 patients failed to complete the questionnaire adequately. Figure 1 shows the flow chart of the selection process and numbers of COPD patients. The baseline characteristics of the 54 patients who completed the questionnaire were compared with the characteristics of the 85 patients who were discharged home but not followed up, and with those of the 32 patients who refused or failed to complete the questionnaire. No significant differences were found among the three groups (all P > 0.05). Before the study commenced, the study protocol was approved by the ethics committees of the three clinical centres of McGill University, and the patients agreed to participate in the questionnaire survey. Medical chart abstraction The medical charts of all patients admitted for an acute exacerbation of their COPD were screened by a medical physician. When a patient met the entry criteria, detailed chart abstraction was performed to retrieve the following information: sociodemographic data, smoking habits, use of long-term oxygen therapy (LTOT) at home, results of lung function tests performed within 12 months prior to hospitalization, causes of acute exacerbation of COPD, medication use, lengths of hospital and intensive care unit (ICU) stays, requirement for mechanical ventilation, comorbidity, and hospital mortality. Comorbidity was quantified according to the Charlson Comorbidity Index. 12 Questionnaire survey The questionnaires used in this study included a HRQoL questionnaire, dyspnoea scale and questions relating to health care service utilization in the last 12 months. HRQoL and dyspnoea were measured using the St. George s Respiratory Questionnaire (SGRQ) 13 and the Medical Research Council (MRC) dyspnoea scale questionnaire, 14 respectively. SGRQ

336 Q Wang and J Bourbeau Initially reviewed eligible patients, n = 282 Discharged home, n =241 Followed up, n = 156 Note: 70 patients died during follow-up. Not followed up, n =85 Reasons: Changed address, telephone number, refused follow-up, etc. Followed for 2 years and alive, n = 86 Completed questionnaire n = 54 Refused questionnaire, n =19 Incomplete questionnaire, n =13 Figure 1 Flow chart of the selection process and numbers of chronic obstructive pulmonary disease patients enrolled at different phases of the study. consists of 76 items and three component indices which are calculated using empirically derived weightings: symptom, activity, and impact scores from which a total score is computed. Scores vary from 0 (no disability) to 100 (maximum disability). The MRC dyspnoea scale questionnaire consists of five questions that pertain to dyspnoea. Based on the response to these questions, the patient s dyspnoea is rated 1 5 in terms of severity, with the higher the grade, the more severe the dyspnoea. Outcome variables Patient outcomes reported in phase I were: (i) mechanical ventilation requirements; (ii) ICU and hospital lengths of stay; and (iii) hospital mortality, home discharge and transfer to a long-term care facility. Patient outcomes reported in phase II were: (i) HRQoL; (ii) ER visits; and (iii) readmission to hospital. Data analysis All data was analysed using the statistical package, SAS (version 6.12; SAS Inc., NC, USA). Results were expressed as mean ± SD for continuous variables or number and percentage for discrete variables. A P- value <0.05 was considered statistically significant. c 2 tests of contingency tables were used to compare proportions for discrete variables, and t-tests were used to compare the means of normally distributed continuous variables between the two groups. The relationship between the quality of life and individual variables was described using Pearson productmoment correlation. A stepwise multiple regression analysis was used to identify the variables that influenced the HRQoL. A multivariate model was used to identify the variables that could best determine the likelihood of frequent ER visits and frequent readmission. RESULTS Hospital care and outcomes The causes of COPD exacerbation included lower respiratory tract infection (65%), congestive heart failure (10%), and pneumothorax or arrhythmias (5%). The cause of the COPD exacerbation was unknown in 20% of patients. A total of 28 patients died during hospitalization and hospital mortality was 9.9%. In total, 241 patients (85.5%) were discharged to their homes and only 13 patients (4.6%) needed long-term care facilities. The length of hospital stay varied from 1 to 696 days, with medians of 9 days in patients who were discharged, 21 days in those who died and 10 days for the whole population. A total of 74 patients (26.2%) were treated in the ICU for a median of 6 days. A total of 56 patients (19.9%) received mechanical ventilation and in 49 (87.5%) this was non-invasive. The major respiratory medications used during hospitalization were inhaled b 2 -agonists, inhaled anticholinergics, systemic corticosteroids, and antibiotics (cephalosporins and quinolones accounted for 60%).

Hospitalization and COPD 337 Table 2 n = 54) Correlation between the St. George s Respiratory Questionnaire scores and related respiratory variables (r-values; Variables Total score Symptom score Activity score Impact score COPD exacerbation 0.525*** 0.592*** 0.369** 0.454*** Dyspnoea grade 0.646*** 0.512*** 0.474*** 0.606*** Readmission 0.456*** 0.330* 0.286* 0.469*** Emergency room visit 0.322* 0.310* 0.415** 0.354** FEV 1 % predicted -0.411** -0.321* -0.474*** -0.338* *P < 0.05; **P < 0.01; ***P < 0.001. Table 3 Multiple regression analysis with St. George s Respiratory Questionnaire scores as outcome variables (n = 54) Variables R 2 b SE P-value Total score 0.57 Dyspnoea grade 6.53 1.44 0.0001 COPD exacerbation 3.42 1.11 0.0031 Symptom score 0.48 Dyspnoea grade 5.47 1.83 0.0044 COPD exacerbation 6.14 1.47 0.0001 Activity score 0.42 Dyspnoea grade 3.57 1.71 0.0056 FEV 1-0.69 0.19 0.0002 Impact score 0.48 Dyspnoea grade 8.51 1.77 0.0001 COPD exacerbation 3.08 1.42 0.0365 b is regression coefficient. SE is standard error of regression coefficient. Health-related quality of life The SGRQ scores (mean ± SD) in 54 patients were: total score 60.5 ± 17.3, symptom score 60.1 ± 21.1, activity score 77.7 ± 19.5, and impact score 50.6 ± 20.3. The mean frequency of COPD exacerbations was 2.2 times per year (median, 2; range, 0 6). The median dyspnoea grade was 3. Quality of life was significantly correlated with COPD exacerbations, dyspnoea grade, FEV 1 % predicted, ER visits and readmissions (Table 2). Multiple regression analysis showed that dyspnoea grade and COPD exacerbation were the major factors influencing quality of life, while FEV 1 only influenced the activity score (Table 3). Factors determining emergency room visits and readmission There were 99 ER visits (mean, 1.83; median, 1; range, 0 9) and 92 readmissions (mean, 1.7; median, 1; range, 0 7) for 54 patients over a 12-month period. A total of 37 patients (68.5%) visited the ER and 35 (64.8%) were admitted to hospital in the last year of review. In total, 92 ER visits (92.9%) and 83 readmissions (90.2%) were due to COPD exacerbations. Patients with frequent ER visits or readmission were those who had severe dyspnoea, poor quality of life and frequent exacerbations of COPD. Multivariate logistic regression models showed that age, comorbidity, FEV 1, SGRQ total score, frequency of COPD exacerbation, LTOT, and family doctor were all variables that influenced ER visits (Table 4), while living alone, frequency of COPD exacerbation, and not having a family doctor were variables that influenced readmission (Table 5). DISCUSSION COPD is one of the more common reasons for healthcare utilization (ER visits and hospitalization) and causes of disability and death in adults, especially in the elderly population. In general, the prognosis of COPD is poor, although someone may survive for many years while suffering from COPD. Many studies have reported hospital mortality rates for COPD of 10 49%, with reported 1-year mortality rates of 20 59%. 9,15 17 The difference in mortality is mainly associated with the patient s age, 18 disease severity, 9 and comorbidity. 19 This study showed that the majority (85.5%) of moderate to severe patients were discharged home after a median of 10 days of treatment for acute exacerbation of COPD, and the hospital mortality rate was only 9.9%, although the mortality rates at 1 year (24.4%) and 2 years (44.9%) were high. Among the patients who were discharged home, only small numbers had been admitted to ICU (17.2%) and required mechanical ventilation (11.9%) during their hospitalization. The length of hospital stay for patients who were discharged was significantly shorter than for those who died. Among the patients who died or required long-term hospital stays, most had received ICU treatment (84.2%) and mechanical ventilation (71%). These results suggest that if patients need intensive care or mechanical ventilation during a COPD exacerbation, they will usually have a protracted hospital stay and poor hospital outcomes. Amongst those discharged home, there was still a 20 and 40% possibility of death in the next 1 and 2 years, respectively. During the last 10 years, measurements of HRQoL or health status have been used widely in the assessment of outcomes in COPD patients. 20,21 Because of the limitations of using physiological measurements, the importance of HRQoL in measuring the impact

338 Q Wang and J Bourbeau Table 4 Multivariate model for emergency room visits in patients with COPD (n = 54) Independent variable b coefficient Odds ratio 95% Confidence interval P-value Age 0.100 0.905 0.847 0.966 0.0028 Comorbidity 0.416 0.659 0.451 0.963 0.0312 FEV 1-2.591 2.075 0.012 0.766 0.0025 SGRQ total score 0.060 0.942 0.904 0.981 0.0042 COPD exacerbation 0.846 1.349 0.274 0.672 0.0002 LTOT 1.580 4.853 1.327 17.75 0.0140 Family doctor -1.401 4.059 1.063 10.51 0.0405 LTOT, long-term oxygen therapy; SGRQ, St. George s Respiratory Questionnaire. Table 5 Multivariate model for readmissions in patients with COPD (n = 54) Independent variable b coefficient Odds ratio 95% Confidence interval P-value Living alone 4.324 0.604 0.001 0.823 0.0092 COPD exacerbation 1.257 0.496 0.032 0.939 0.0081 Family doctor -3.357 1.435 0.136 1.337 0.0076 and outcome of COPD is increasingly being acknowledged. COPD limits exercise capacity and impairs HRQoL. The degree of impairment of HRQoL is associated with the severity of illness and the frequency of exacerbation. Patients alive at 6 months after an exacerbation, commonly consider their quality of life to be fair or poor. 12 In this study, about 60% of the patients survived for a median of 2 years after hospitalization and discharge for a COPD exacerbation, but their quality of life was quite poor. Many factors, such as air flow limitation, comorbidity, frequency of COPD exacerbations, and activities of daily living can impact on HRQoL in COPD patients. 22 24 However, in this study, only frequency of COPD exacerbation and dyspnoea grade were strongly correlated with all SGRQ scores and influenced the HRQoL of the patients. Air flow limitation (FEV 1 ) only influenced the SGRQ activity score. Previous studies have shown that although changes in physiological indicators may be related to some aspects of HRQoL, lung function is a relatively weak predictor for HRQoL in COPD patients. 25,26 Long-term deterioration in FEV 1 occurs so slowly that it is not a useful outcome measure. Therefore, HRQoL, which is a relatively independent objective index, should be used more regularly to better understand health outcomes of COPD patients. Poor quality of life is related to the likelihood of hospital admission and to increased use of resources. Readmission to hospital is very common among COPD patients discharged from hospital after an acute exacerbation. Most studies have shown that readmission rates 1 year after a COPD exacerbation were high (46 86%) and that patients with a high risk of readmission or ER visit had poor HRQoL. 10,11,27 In this study, of 54 patients who were followed for a median of 24 months and surveyed by questionnaire, 37 (68.5%) visited the ER and 35 (64.8%) had been readmitted to hospital in the previous 12 months. Over 90% of the ER visits were due to a COPD exacerbation. Reasons for hospital admission in COPD patients are complex, although often they result from a failure of the usual therapy. Besides COPD exacerbation, this study showed that patients who lived alone were predisposed to hospital admission. Perhaps this is because patients who live alone have poor health and their disease is not well managed when they suffer a relapse. Patients with poor HRQoL, severe dyspnoea and frequent COPD exacerbations had frequent ER visits and readmissions to hospital. Advanced age, frequent acute exacerbations of COPD, comorbidity, poor SGRQ total scores, lower FEV 1, and requirement for LTOT were the factors predisposing to ER visits. In addition, patients who had no family doctor were predisposed to ER visits. It is not surprising that patients receiving LTOT were predisposed to ER visits, as it is usually only those with disease and poor quality of life who require oxygen therapy. It is clear that the reasons for ER visits and hospital admissions in COPD patients is quite complex. In addition to the disease itself, age, comorbidity and sociomedical support (living alone and not having a family doctor) may play an important role in determining health-care service utilization. Improving a patient s socio-medical network may be useful in reducing ER visits and hospital admissions in COPD patients, as it is difficult to change many of the other factors influencing ER visits and hospitalization. Since this was a retrospective study, the analysis was limited and there is a potential selection bias in that only patients with moderate or severe COPD were studied. It is unclear whether HRQoL would be different in patients with mild COPD, but this study was focused more on the effect of hospitalization. Lastly, patients who died during the follow-up period could not be interviewed and assessed.

Hospitalization and COPD 339 In summary, this study has shown that patients with moderate and severe COPD have poor long-term outcomes. Although more than 50% of patients survived more than 2 years post-discharge, their HRQoL was poor. Frequent exacerbation of COPD and severe dyspnoea were two major variables that contributed to poor HRQoL. ER visits and readmissions were very common among these patients. Advanced age, comorbidity, frequent COPD exacerbations, lower FEV 1, high SGRQ total scores, and requirement for LTOT were all predisposing factors for ER visits. In addition, the patients social and medical networks have important effects on health-care service utilization in COPD patients. This study can help to better understand hospital and long-term outcomes, and especially to understand HRQoL and health service utilization in COPD patients. 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