Phenotypic Characteristics of Patients With Chronic Obstructive Pulmonary Disease After Stratification for the Short Physical Performance Battery Summary Score.

ABSTRACT

OBJECTIVE: To assess the phenotypic characteristics of patients with chronic obstructive pulmonary disease (COPD) after stratification for Short Physical Performance Battery (SPPB) summary scores and to determine phenotypic characteristics of the SPPB summary score at the start of pulmonary rehabilitation (PR). DESIGN: Retrospective, cross-sectional. SETTING: Baseline assessment for PR program. PARTICIPANTS: Patients with COPD (n=900; age 65±8y, 52% male, forced expiratory volume in the first second of expiration, 43% [interquartile range, 31%-62%] predicted). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Patients were stratified according to their SPPB summary scores into low-performance (LP), moderate-performance (MP), or high-performance (HP) groups. Furthermore, lung function, arterial blood gases, body composition, physical capacity, lower limb muscle strength and endurance, and symptoms of anxiety and depression were assessed. RESULTS: Generally, physical capacity and muscle function were lower and scores for symptoms of anxiety and depression were higher in LP patients than MP and HP patients (all values, P<.01). However, 25% of HP patients with COPD scored high on symptoms of anxiety and/or depression (≥10 points), and HP patients still had on average an impaired physical capacity (median, 6-minute walk test [6MWT] distance of 69% predicted). Furthermore, age and 6MWT distance (m) were the only independent predictors in a multivariate regression model, explaining 29% of the variance in SPPB summary score. CONCLUSIONS: In COPD, LP patients have the worst physical and emotional functioning. However, HP patients can still exhibit physical and emotional impairments. Because the explained variance in SPPB summary score is low, SPPB should not be considered as a test to discriminate between patients with COPD with a low or preserved physical capacity and emotional status.