Association of step count with PROMIS pediatric health-related quality of life measures in children and adolescents with persistent asthma

Uncontrolled or partly controlled asthma was defined by meeting any one of three criteria: (1) a forced expiratory volume in 1 second less than 80% of predicted; (2) one or more exacerbations requiring systemic corticosteroids in the past year; or (3) parent or child report of partly controlled or uncontrolled asthma, using the Global Initiative for Asthma guidelines.6 Baseline asthma severity, assessed by study physicians, was approximated by National Asthma Education and Prevention Program treatment step.7 The study was approved by Duke University (coordinating center), UNC-Chapel Hill, and Boston Children's Hospital institutional review boards and listed on ClinicalTrials.gov (NCT03933540). A linear mixed regression model (including age, sex, race, ethnicity, body mass index, parent's education level, and time point as fixed effects) examined the association between a child's step count and each PROMIS domain as the model outcome over the 4-week period, while accounting for baseline asthma severity. Characteristic n (%) Age, y (mean, SD) 11.45, 2.58 Female sex 49 (47%) Race White 35 (33%) Black 47 (45%) Asian 2 (2%) Mixed race 15 (14%) Other 6 (6%) Hispanic ethnicity 17 (16%) Body mass index Normal (fifth to 85th percentile) 50 (48%) Overweight (greater than 85th to 94th percentile) 18 (17%) Obese (greater than 95th percentile) 37 (35%) Table I Demographic and clinical characteristics of study participants (n = 105) Average daily steps by wk Wk 1 Wk 2 Wk 3 Wk 4 All participants, n (mean [SD]) 82 (8523 [2773]) 84 (8640 [2803]) 78 (8045 [2872]) 74 (7506 [2758]) Aged 8-11 y 44 (9134 [2472]) 46 (8915 [2631]) 45 (8644 [2687]) 42 (8070 [2705]) Aged 12-17 y 38 (7816 [2962])∗ 38 (8307 [2999]) 33 (7228 [2955])∗ 32 (6766 [2690])∗ Table II Relationship between average daily steps and PROMIS health-related quality of life domains