Objectively Measured Steps/Day in Patients With Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis.

Background: Although individual studies have reported on the number of steps/day taken by individuals with chronic obstructive pulmonary disease (COPD), this evidence has not been systematically reviewed or synthesized.

Methods: MEDLINE and PsycINFO were searched for studies reporting objectively-measured steps/day and percent predicted forced expiratory volume in 1 second (FEV%) in patients with COPD. Meta-analyses were used to estimate steps/day across studies, while metaregression was used to estimate between-study variance based on clinical and demographic factors (year and location of study, activity monitor brand, number of days wearing the monitor, whether participants were about to enter pulmonary rehabilitation, 6-minute walk distance (6MWD), FEV%, age, and sex).

Results: 38 studies including 2621 participants met inclusion criteria. The pooled mean estimate was 4579 steps/day (95% CI:4310 to 5208) for individuals with COPD. Only 6MWD, FEV% and whether patients were about to undergo pulmonary rehabilitation explained a significant portion of the variance (P < 0.1) in univariate meta-regression. In a multivariate model including the above risk factors, only FEV% was associated with steps/day after adjustment for other covariates.

Conclusions: These results indicate that patients with COPD achieve extremely low levels of physical activity as assessed by steps/day, and that severity of airflow obstruction is associated with activity level.