Daily Physical Activity in Patients With COPD After Hospital Discharge in a Minority Population

Background: Low physical activity in patients with chronic obstructive pulmonary disease (COPD) is associated with increased morbidity and mortality. To inform the design of a home-based physical activity promotion program for patients with COPD recently discharged from a minority-serving hospital, we conducted a cohort study to evaluate objectively measured daily physical activity and patient-reported outcomes.

Methods: This was a 12-week prospective cohort study of patients with a physician diagnosis of COPD recently hospitalized (≤ 12 weeks) for respiratory symptoms. Daily physical activity was recorded using wrist-based and "clip-on" pedometers, and analyzed as mean daily step counts averaged over 7 days.

Results: Twenty-two patients were enrolled a median (interquartile range, [IQR]) of 14 (7 to 29) days after hospital discharge. The median daily step count (IQR) in the first week after enrollment (week 1) was 3710 (1565 to 5129) steps. The median within-person change in daily step count (IQR) from week 1 to week 12 was 314 (-30 to 858) steps (p=0.28). Within-person correlation of week-to-week daily step counts was high (r ≥ 0.75). Time from hospital discharge to enrollment was not correlated with mean daily step counts on week 1 (r= -0.13) and only weakly correlated with change in mean daily step counts from week 1 to week 12 (r=0.37).

Conclusions: Daily physical activity was variable in this cohort of recently hospitalized patients with COPD, but with little within-person change over a 12-week period. These observations highlight the need for flexible physical activity promotion programs addressing the needs of a heterogeneous patient population.