Influence of basal physical activity and air quality on a walking programme in patients with COPD.

The majority of COPD patients achieved the walking programme goal of increasing steps per day.

• 42 out of 72 patients (58%) achieved programme goals, defined as an increase of >600 steps/day.
• The study was a 3-month walking programme with self-documented physical activity tracked using pedometers.
• Mean COPD Assessment Test score was 11.5 and mean FEV₁ was 54% predicted across the study population.
• Patients were recruited from a university hospital and required peripheral oxygen saturation (SpO₂) ≥94% for inclusion.

Air quality index (AQI) did not influence walking programme outcomes in COPD patients.

• Mean AQI across the study period was 71±10.7.
• AQI showed no significant association with programme success (OR 1.018; 95% CI 0.949 to 1.092; p=0.622).
• AQI was monitored daily from a central site throughout the 3-month programme.
• This finding was confirmed in multivariate logistic regression analysis.

Higher baseline physical activity (YPAS score) was a key predictor of walking programme success.

• Responders had significantly higher baseline Yale Physical Activity Survey (YPAS) scores compared to non-responders.
• YPAS score was a strong independent predictor of success in multivariate logistic regression (OR 33.197; 95% CI 6.197 to 185.636; p<0.001).
• The YPAS was used to assess sedentary status at baseline.
• This finding suggests that less sedentary patients at baseline were more likely to respond to the walking programme.

Higher baseline FEV₁ was independently associated with walking programme success.

• FEV₁ was a significant predictor of programme success in multivariate logistic regression (OR 1.108; 95% CI 1.005 to 1.222; p=0.039).
• The mean FEV₁ for the study population was 54% predicted.
• FEV₁ was measured as percent predicted in functional testing at baseline.

Common clinical and demographic variables were not significantly associated with walking programme success.

• Variables including age, sex, Body Mass Index, comorbidities, and exacerbation history showed no significant associations with programme outcome.
• 72 patients with COPD were recruited for the prospective observational study.
• These null findings suggest that standard demographic and clinical characteristics do not predict walking programme response in this population.