Disability in moderate chronic obstructive pulmonary disease: prevalence, burden and assessment - results from a real-life study

Background: The role of disability and its association with patient-reported outcomes in the nonsevere forms of chronic obstructive pulmonary disease (COPD) has never been explored. Objectives: The aim of this study was to assess, in a cross-sectional real-life study, the prevalence and degree of disability in moderate COPD patients and to assess its association with health status, illness perception, risk of death and well-being. Methods: Moderate COPD outpatients attending scheduled visits were involved in a quantitative research program using a questionnaire-based data collection method. Results: Out of 694 patients, 17.4% were classified as disabled and 47.6% reported the loss of at least one relevant function of daily living. Disabled patients did not differ from nondisabled patients in terms of working status (p = 0.06), smoking habits (p = 0.134) and ongoing treatment (p = 0.823); however, the former showed a significantly higher disease burden as measured by illness perception, health status and well-being. The stepwise regression analysis showed that the modified Medical Research Council (mMRC) score was the most relevant factor related to COPD disability (F = 38.248; p = 0.001). Patient stratification was possible according to the forced expiratory volume in 1 s (FEV 1 ) value and an mMRC score ≥ 2, which identified disabled patients, whereas the mMRC values were differently associated with the risk of disability. Conclusion: A significant proportion of individuals with moderate COPD reported a limitation of daily life functions, with dyspnea being the most relevant factor inducing disability. Adding the evaluation of patient-reported outcomes to lung function assessment could facilitate the identification of disabled patients.