JMIR Publications

ABSTRACT

Background:

Questionnaire-based symptom assessment may introduce recall bias and lacks bidirectional exploration, which seems likely since the direction of associations between physical activity (PA), sedentary time (ST) and symptoms is unclear.

Objective:

Therefore, this study investigates the direction of the association between PA, ST and symptoms in patients with COPD using accelerometry and ecological momentary assessment (EMA).

Methods:

A subsample from the FAntasTIGUE study answered eight randomly timed EMA questionnaires daily for five days. Ten symptoms were rated on a 7-point Likert scale: ‘I feel relaxed, short of breath, energetic, cheerful, insecure, irritated, satisfied, anxious, tired, and mentally fit’. Concurrently, step count and ST were measured using the ActiGraph GT9X Link. Step count and ST 15 and 30 minutes pre- and post-EMA were used in multilevel models, controlled for pre-EMA steps and ST, and the previous EMA score. Significant confounders were used as covariates and patient ID as random intercept.

Results:

Thirty-four patients (56% men, 66±7 years, FEV1 52.1±19.7 % predicted, 1035 EMA responses) were included. Feeling more relaxed was associated with a higher step count 15 minutes post-EMA (P=.046). Conversely, higher step count 15 and 30 minutes pre-EMA was associated with feeling less relaxed (P=.03; P=.01), more short of breath (both P<.001) and tired (P<.001; P=.005). Higher ST 15 and 30 minutes pre-EMA was associated with feeling more anxious (P=.02; P=.03).

Conclusions:

A bidirectional association of feeling relaxed with PA was found in patients with COPD. Higher step count was related to feeling more short of breath and tired, while higher ST was associated with heightened anxiety.