Association between multi-component initiatives and physical activity-related behaviors: interim findings from the Healthy Schools Healthy Communities initiative.

BACKGROUND: Although successful, assessment of multi-component initiatives (MCIs) prove to be very challenging. Further, rigorous evaluations may not be viable, especially when assessing the impact of MCIs on long-term population-level behavior change (e.g., physical activity (PA) and health outcomes (e.g., childhood obesity). The purpose of this study was to use intensity scoring, to assess whether higher intensity MCIs implemented as part of Healthy Schools Healthy Communities (HSHC) were associated with improved physical activity and reduced sedentary behaviors among youth (dependent variables).
METHODS: PA-related interventions were assigned point values based on three characteristics: 1) purpose of initiative; 2) duration; and 3) reach. A MCI intensity score of all strategies was calculated for each school district and its respective community. Multivariate longitudinal regressions were applied, controlling for measurement period, Cohort, and student enrollment size.
RESULTS: Strategy intensity scores ranged from 0.3 to 3.0 with 20% considered "higher-scoring" (score > 2.1) and 47% considered "lower-scoring" (< 1.2). Average MCI intensity scores more than tripled over the evaluation period, rising from 14.8 in the first grant year to 32.1 in year 2, 41.1 in year 3, and 48.1 in year 4. For each additional point increase in average MCI intensity score, the number of days per week that students reported PA for at least 60 min increased by 0.010 days (p < 0.01), and the number of hours per weekday that students reported engaging in screen time strategies decreased by 0.006 h (p < 0.05). An increase of 50 points in MCI intensity score was associated with an average 0.5 day increase in number of weekdays physically active and an increase of 55 points was associated with an average decrease of 20 min of sedentary time per weekday.
CONCLUSIONS: We found a correlation between intensity and PA and sedentary time; increased PA and reduced sedentary time was found with higher-intensity MCIs. While additional research is warranted, practitioners implementing MCIs, especially with limited resources (and access to population-level behavior data), may consider intensity scoring as a realistic and cost effective way to assess their initiatives. At a minimum, the use of intensity scoring as an evaluation method can provide justification for, or against, the inclusion of an individual strategy into an MCI, as well as ways to increase the likelihood of the MCI impacting population-health outcomes.