TY - JOUR T1 - Seasonal variability in physical activity in healthy subjects and patients with early COPD JF - European Respiratory Journal JO - Eur Respir J VL - 38 IS - Suppl 55 SP - p279 AU - Miek Hornikx AU - Hans Van Remoortel AU - Kristien De Bent AU - Erica Balligand AU - Chris Burtin AU - Daniel Langer AU - Rik Gosselink AU - Marc Decramer AU - Wim Janssens AU - Thierry Troosters Y1 - 2011/09/01 UR - http://erj.ersjournals.com/content/38/Suppl_55/p279.abstract N2 - Background: Physical activity (PA) is an important parameter related to morbidity in both patients with COPD and in healthy subjects. Little is known on the variability in PA measurements. We aimed at computing the intra-individual variability of PA assessments within one week and when measured 6 months apart in stable subjects.Methods: 78 Subjects (Age 63±7 years; 6MWD 92±9% pred), including 45 healthy persons and 33 patients with COPD (23 GOLD I;10 GOLD II), were instructed to wear the SenseWear Armband during 7 consecutive days, six months apart, to measure PA. The difference in the average amount of steps (PAsteps) and the time spent in moderate PA (> 3 METS) (PAmod) were chosen as primary outcomes. The coefficiënt of variation (CV) was calculated for these 7 days. Outcomes are linked to the season of assessment.Results: The CV for the number of steps was 33±14% and accounted 59±28% for PAmod. Table 1 provides an overview of physical activity at follow-up for the four seasons.View this table:Table 1. Seasonal follow-up of PAConclusion: Our analysis indicate that, within one visit, the variability in PA is large. Average PA is reduced during autumn and winter time. Trials using PA as an outcome should take these seasonal fluctuations into account. ER -