Measurement characteristics of activity-related psychosocial measures in 8- to 10-year-old African-American girls in the Girls health Enrichment Multisite Study (GEMS)

Abstract

Background. This paper presents reliability and validity analyses of physical activity-related psychosocial questionnaires completed by 8- to 10-year-old African-American girls at baseline and follow-up assessments of pilot intervention studies in the Girls health Enrichment Multi-site Study (GEMS). Methods. Two hundred ten girls participated in the GEMS 12-week pilot studies and had their height and weight measured, wore an accelerometer for 3 days and completed a measure of their usual physical activity (PA) at baseline and after the 12-week intervention. Subgroups of girls also completed physical activity-related psychosocial measures at these two time points including: (a) self-concept; (b) self-efficacy; (c) outcome expectancies; and d) preferences. Principal components analysis was conducted on the psychosocial measures obtained at baseline. Cronbach's alpha and test–retest reliability were computed. Convergent validity was assessed by correlating the baseline psychosocial measures with baseline physical activity measures and body mass index (BMI). Results. The following sub-scales were derived: Activity Preference, Positive Expectancies and Negative Expectancies for physical activity. Physical Performance Self-Concept and Self-Efficacy for physical activity were kept as single dimensional scales. Sub-scales, derived from principal components analyses, were Activity Preference, Positive Expectancies, and Negative Expectancies for physical activity. Internal consistency estimates for the various scales were substantial to excellent (0.67–0.85), while test–retest reliability estimates were fair to moderate (0.22–0.56). Correlations between the PA psychosocial sub-scales and measured levels of activity measures showed evidence of convergent validity for the Activity Preference sub-scale, although social desirability may have influenced the significant associations observed. Conclusions. The Activity Preference was a fairly reliable and valid measure. Further studies are needed to examine the utility of activity-related psychosocial measures in interventions to increase physical activity among preadolescent African-American girls.