Reliability and internal consistency of scales for parental and peer support for physical activity in children and adolescents in Chile

AimTo evaluate the reliability and internal consistency of scales for parental and peer support for physical activity (PA) in children and adolescents in Chile. Subject and methodsThis is a cross-sectional study with a sample of 160 youth, including 59 children and 101 adolescents, from the city of Vi & ntilde;a del Mar (Chile). The parental support for PA was evaluated through the Family Support for PA Scale, while peer support was determined by the Friends Support for PA Scale, which are five-item and four-item Likert-type scales, respectively. Cronbach's alpha coefficients were calculated to evaluate the reliability, and the internal consistency was determined by test-retest, Kendall's tau-b coefficients. ResultsThe Family Support for PA Scale showed satisfactory reliability (Cronbach's alpha > 0.70) across the total sample and stratified by age and sex. In the second evaluation (retest), there was an increase in Cronbach's alpha values across all groups except for girls, suggesting enhanced reliability. This scale also showed strong internal consistency and moderate to high reliability in four out of five questions in all analysed groups (k = 0.50-0.69). The Friends Support for PA Scale indicated sufficient internal consistency, with an improvement in the second evaluation. Concerning reliability, data varied across the analysed questions, from low to moderate. ConclusionThe Family Support for PA Scale showed strong internal consistency and moderate to high reliability for most questions. At the same time, the Friends Support for PA Scale exhibited sufficient internal consistency and low to moderate reliability across questions.