Physical frailty characteristics have a differential impact on symptoms as measured by the CAT score: an observational study

BACKGROUND: The physical frailty status affects the health status of patients with chronic obstructive pulmonary disease (COPD). The objective was to determine if the individual physical frailty characteristics have a differential impact on the CAT score. METHODS: This observational study included 137 patients with stable COPD. Physical frailty was measured with unintentional weight loss, low physical activity, exhaustion, slow walking speed and low grip strength and health status assessed with the COPD Assessment test (CAT). The following variables were evaluated as potential determinants of CAT: sex, age, body mass index, smoking, dyspnea, exacerbations, comorbidities, %FEV1, %FVC, anxiety and depression. RESULTS: The prevalence of characteristics for individual frailty was as follows: low grip strength, 60.6%; low physical activity, 27.0%; exhaustion, 19.7%; slow walking speed, 9.5%; and unintentional weight loss, 7.3%. A total of 17.5% of the patients were non-frail, 73.7% were pre-frail and only 8.7% were frail. One of the five frailty characteristics, exhaustion (adjusted β coefficient 5.12 [standard error = 1.27], p = 0.001) was an independent determinant of CAT score in the final regression model which was adjusted by other independent determinants of CAT (dyspnea, exacerbations and anxiety). CONCLUSIONS: Due to the fact that exhaustion is a frequent and relevant psychological symptom on CAT score of patients with COPD, interventions should reduce that stress. Future research should explore how exhaustion persists or remits over time.