Validity and reliability of HOP-Up: a questionnaire to evaluate physical activity environments in homes with preschoolaged children

Background: Early identification of physical activity (PA) opportunities in the home and neighborhood environment may help obesity prevention efforts in households with young children. This cross-sectional study's purpose was to develop a brief, easy-to-use, self-report inventory called Home Opportunities for Physical activity check-Up (HOP-Up), to evaluate the availability and accessibility of PA space and equipment in and near homes with preschool children, and establish its validity and reliability. Methods: The HOP-Up was field tested by two trained researchers and parents of preschool-aged children (n = 50; 71 % white). To establish criterion validity, researchers were the 'gold standard' and visited participants' homes to assess their PA environments using the HOP-Up, while participants separately completed their HOP-Up. Two weeks later, parents completed the HOP-Up online for test-retest reliability. After minor survey refinements, exploratory and confirmatory factor analysis using a split-half cross validation procedure was conducted in a larger sample of participants (n = 655, 60 % white) who completed the HOP-Up online to examine its factor structure. To establish convergent validity, correlations were conducted to compare HOP-Up scales from the factor solution generated with PA behavior and cognitions, and reported screen time. Results: Intra-class correlations (ICCs) examining HOP-Up item agreement between researcher and parents revealed slight to substantial agreement (range 0.22 to 0.81) for all items. ICCs for all HOP-Up items ranged from fair to substantial agreement between parent responses at both time points (range 0.42 to 0.95). Exploratory factor analysis revealed a five factor solution (18 items), supported eigen values, scree plots, review for contextual sense, and confirmatory factor analysis. Additionally, there were significant (p < 0.05) positive correlations among nearly all five HOP-Up scales with parent and child physical activity levels (range 0.08 to 0.35), and values parents placed on PA for self and child (range 0.16 to 0.35), and negative correlations of Neighborhood Space & Supports for PA scale with parent and child reported screen time (r = -0.11, r = -0.13, respectively). Conclusions: Findings support the psychometric properties of this brief, easy-to-use, HOP-Up questionnaire, which may help parents, prevention researchers, residential planners, and practitioners increase their understanding of how the home environment-inside, outside, and the neighborhood-impacts preschool children's physical activity levels.