People with hospitalised acute exacerbations of chronic obstructive pulmonary disease (AECOPD) exhibit low levels of physical activity (PA) and increased risks of future exacerbations. While methods to objectively measure and express PA are established for people with stable COPD, less clarity exists for people during AECOPD. Further, the relationship between PA during AECOPD and clinically relevant outcomes remains uncertain. The purpose of the study was to evaluate how much PA (step count and intensity) people accumulate during hospitalised AECOPDs, and the effect of accumulated inpatient PA (expressed via differing metrics) on length of stay (LOS), PA recovery, and readmission risk. This study was a secondary analysis of prospective observational cohort data collected with Actigraph wActiSleep-BT devices from patients with AECOPD in a Melbourne hospital from 2016 to 2018. Step counts and PA intensity throughout the hospital admission and at one-month follow-up were collected and analysed. Sixty-eight participants were recruited for inpatient measurement, and 51 were retained for follow-up. There were no significant changes in step count or intensity across the inpatient days, but 33/51 (65%) of participants demonstrated a clinically meaningful improvement in steps per day from 3817.0 to 6173.7 at follow-up. Participants spent most time sedentary and in light PA, with both PA metrics demonstrating significant influences on LOS and follow-up PA intensity, but with generally low explanatory power (R2 value range 7-22%). Those who had LOS < 5 days spent significantly less time sedentary and more time in light PA than those with LOS ≥ 5 days (p < 0.001 for both). Time spent sedentary or in light PA appears to be the most promising metric to associate with clinically relevant outcomes related to recovery following AECOPD. These findings can inform future clinical practice for the evaluation of inpatient PA to better establish its role in the clinical management of patients with AECOPD.
Keywords: COPD; disease exacerbation; hospital admission; inpatient; physical activity.