Sustained effects of integrated COPD management on health status and exercise capacity in primary care patients

Annemarije L Kruis1, Joan van Adrichem2, Magda R Erkelens2, Huub Scheepers3, Hans in ’t Veen4, Jean WM Muris5, Niels H Chavannes11Department of Public Health and Primary Care, Leiden University Medical Center, Leiden, 2Physiotherapy Center De Beweging, Rotterdam, 3Well-being Medical Center, Bocholtz-Simpelveld, 4Department of Pulmonary Diseases, Sint Franciscus Gasthuis, Rotterdam, 5Department of General Practice, Maastricht University Medical Center, The NetherlandsBackground: Chronic obstructive pulmonary disease (COPD) constitutes a growing health care problem worldwide. Integrated disease management (IDM) of mild to moderate COPD patients has been demonstrated to improve exercise capacity and health status after one year, but long-term results are currently lacking in primary care.Methods: Long-term data from the Bocholtz study, a controlled clinical trial comparing the effects of IDM versus usual care on health status in 106 primary care COPD patients during 24 months of follow-up, were analyzed using the Clinical COPD Questionnaire (CCQ). In addition, the Kroonluchter IDM implementation program has treated 216 primary care patients with mild to moderate COPD since 2006. Longitudinal six-minute walking distance (6MWD) results for patients reaching 24 months of follow-up were analyzed using paired-sample t-tests. In prespecified subgroup analyses, the differential effects of baseline CCQ score, Medical Research Council (MRC) dyspnea score, and 6MWD were investigated.Results: In the Bocholtz study, subjects were of mean age 64 years, with an average postbronchodilator forced expiratory volume in one second (FEV1) of 63% predicted and an FEV1/forced vital capacity (FVC) ratio of 0.56. No significant differences existed between groups at baseline. CCQ improved significantly and in a clinically relevant manner by 0.4 points over 24 months; effect sizes were doubled in patients with CCQ > 1 at baseline and tripled in patients with MRC dyspnea score > 2. In the Kroonluchter cohort, 56 subjects completed follow-up, were of mean age 69 years, with an FEV1/FVC ratio of 0.59, while their postbronchodilator FEV1 of 65% predicted was somewhat lower than in the total group. 6MWD improved significantly and in a clinically relevant manner up to 93 m at 12 months and was sustained at 83 m over 24 months; this effect occurred faster in patients with MRC dyspnea score > 2. In patients with baseline 6MWD < 400 m the improvement remained >100 m at 24 months.Conclusion: In this study, IDM improved and sustained health status and exercise capacity in primary care COPD patients during two years of follow-up. Improvements in health status are consistently higher in patients with CCQ > 1 at baseline, being strongest in patients with baseline MRC dyspnea score >2. Improvements in exercise capacity remain highest in patients with 6MWD < 400 m at baseline and seem to occur earlier in patients with MRC dyspnea score >2.Keywords: chronic obstructive pulmonary disease, disease management, integrated care, pulmonary rehabilitation, primary car