Co-occurrence of Physical Frailty and COPD and Association With Disability and Mortality

BACKGROUND: Physical frailty commonly is associated with COPD, and its evaluation in COPD may provide important prognostic information for risk stratification. RESEARCH QUESTIONS: What are the comorbid associations of physical frailty with COPD? Does physical frailty singly and in combination with FEV1 percent predicted and dyspnea predict disability and mortality? STUDY DESIGN AND METHODS: Prospective cohort study of community-dwelling adults 55 years of age or older in the Singapore Longitudinal Ageing Study. Baseline data of 1,162 participants with COPD and 3,465 participants without COPD included physical frailty, FEV1 percent predicted, and dyspnea. Outcome measures were prevalent and incident instrumental activities of daily living (IADL) and basic activities of daily living (ADL) disability at 3 to 5 years of follow-up and all-cause mortality up to 11 years. ORs, hazard ratios, and 95% CIs were adjusted for socioeconomic status, smoking, and comorbidity count. RESULTS: Baseline prevalence of prefrailty (48.8%) and frailty (6.8%) in participants withCOPD were significantly higher than in participants without COPD: frailty OR, 1.61; 95% CI, 1.15- 2.26. Prefrailty or frailty was associated significantly with twofold increased odds of prevalent and incident IADL and basic ADL disability and mortality in participants with COPD. In combination with FEV1 percent predicted of < 80% or dyspnea, frailty was associated with substantially increased threefold to fourfold odds of prevalent and incident IADL and basic ADL disability, and twofold to threefold increased mortality hazard. A summary score combining physical frailty, FEV1 of < 80%, and dyspnea predicted steeper risk gradients of prevalent and incident IADL and basic ADL disability and mortality across four risk categories (0, 1, 2, 3-5), with the highest risk category predicting between sevenfold and 8.5-fold increased risks in crude analyses, which remained significantly high after covariate adjustment. INTERPRETATION: The study supports the use of physical frailty in addition to lung function and dyspnea in multidimensional evaluation of COPD.