Validation of the SOPLAY direct observation tool with an accelerometry-based physical activity monitor.

BACKGROUND: The System for Observing Play and Leisure Activities (SOPLAY) is a direct observation instrument designed to assess group physical activity and environmental contexts. The purpose of this study was to test the convergent validity of the SOPLAY using temporally matched data from an accelerometry-based activity monitor. METHODS: Accelerometry-based physical activity data were obtained from 160 elementary school children from 9 after-school activity programs. SOPLAY coding was used to directly observe physical activity during these sessions. Analyses evaluated agreement between the monitored and observed physical activity behavior by comparing the percent of youth engaging in physical activity with the 2 assessments. RESULTS: Agreement varied widely depending on the way the SOPLAY codes were interpreted. Estimates from SOPLAY were significantly higher than accelerometer PA levels when codes of walking and vigorous were used (in combination) to reflect participation in moderate to vigorous PA (MVPA). Estimates were similar when only SOPLAY codes of vigorous were used to define MVPA (Difference = 1.33 ± 22.06%). CONCLUSIONS: SOPLAY codes of walking corresponded well with estimates of Light intensity PA. Observations provide valid indicators of MVPA if coding is based on the percentage of youth classified as "vigorous."

Prediction of BMI change in young children with the family nutrition and physical activity (FNPA) screening tool.

BACKGROUND: Youth obesity prevention practices would be enhanced if modifiable risk factors can be identified before children become overweight. PURPOSE: This study evaluated the predictive validity of the Family Nutrition and Physical Activity (FNPA) screening tool, a behaviorally based screening tool designed to assess family environments and behaviors that may predispose youth to becoming overweight. METHODS: Parents from a large urban school district completed the FNPA screening when children were in first grade. One-year change in measured body mass index (BMI) was used as the primary outcome, and this was computed using the relative change in distance from the BMI value at the 50th percentile. Descriptive, correlation, and mixed modeling analyses were used for survey validation. RESULTS: Over half of the participants exhibited an increase in BMI percentile over the 1-year follow-up with an average change of 0.51 +/- 11.5% which is indicative of trends to overweight. Although baseline BMI predicted BMI at follow-up, the FNPA total score explained unique variance in child BMI at follow-up after accounting for baseline BMI, parent BMI, and other demographic variables (p = 0.049). CONCLUSIONS: This study demonstrates the potential validity of a simple, easy-to-use screening tool for identifying children that may be at risk for becoming overweight.

Development and preliminary validation of a Family Nutrition and Physical Activity (FNPA) screening tool.

BACKGROUND: Parents directly influence children's physical activity and nutrition behaviors and also dictate the physical and social environments that are available to their children. This paper summarizes the development of an easy to use screening tool (The Family Nutrition and Physical Activity (FNPA) Screening Tool) designed to assess family environmental and behavioral factors that may predispose a child to becoming overweight. METHODS: The FNPA instrument was developed using constructs identified in a comprehensive evidence analysis conducted in collaboration with the American Dietetics Association. Two or three items were created for each of the ten constructs with evidence grades of II or higher. Parents of first grade students from a large urban school district (39 schools) were recruited to complete the FNPA screening tool and provide permission to link results to BMI data obtained from trained nurses in each school. A total of 1085 surveys were completed out of the available sample of 2189 children in the district. Factor analysis was conducted to examine the factor structure of the scale. Mixed model analyses were conducted on the composite FNPA score to determine if patterns in home environments and behaviors matched some of the expected socio-economic (SES) and ethnic patterns in BMI. Correlations among FNPA constructs and other main variables were computed to examine possible associations among the various factors. Finally, logistic regression was used to evaluate the construct validity of the FNPA scale. RESULTS: Factor analyses revealed the presence of a single factor and this unidimensional structure was supported by the correlation analyses. The correlations among constructs were consistently positive but the total score had higher correlations with child BMI than the other individual constructs. The FNPA scores followed expected demographic patterns with low income families reporting lower (less favorable) scores than moderate or high income families. Children with a total score in the lowest tertile (high risk family environment and behaviors) had an odds ratio (OR) of 1.7 (95% CI = 1.07 - 2.80) compared to children with a total score in the highest tertile (more favorable family environment and behaviors) but this effect was reduced when parent BMI was included as a covariate. CONCLUSION: The results support the contention that the FNPA tool captures important elements of the family environment and behaviors that relate to risk for child overweight.