Measurement properties of the one-minute sit-to-stand test in children and adolescents with cystic fibrosis: A multicenter randomized cross-over trial

Functional exercise capacity assessment is recommended in children with cystic fibrosis (CF). The six-minute walk test (6MWT) is a valid evaluation of exercise capacity but can be technically complex. Inversely, the sit-to-stand test (STST) is a simple method to evaluate exercise capacity, and is validated in healthy children and adults with CF. This study aimed to evaluate STST measurement properties in children and adolescents with CF. In this multicenter study, children with CF (6 to 18 years) performed two iterations of both the STST and the 6MWT in a randomized order. Criterion validity was determined by assessing correlations between STST repetitions and 6MWT distance (6MWD). Intra-rater reliability, test-retest repeatability, mean bias and limits of agreement were also assessed. Relationships with other outcomes (i.e. respiratory and quadriceps muscle strength) and cardio-respiratory responses were analysed for both tests. Thirty-six children with CF were included (mean age 12.0 ±3.5 years and FEV1 95.8 ±25.0%). On average, 39.6 ±10.5 repetitions were performed during the STST and mean 6MWD was 596.0 ±102.6 meters. STST number of repetitions was significantly correlated with 6MWD (r = 0.48; p