A Multi-Site Study of implementing a School-Based Health Promotion Intervention in Sweden – Changes in Readiness and Implementation Outcomes

Background : Effective implementation of evidence-based interventions is essential to reducing the disease burden. Contextual barriers can hinder implementation and reduce effectiveness. Assessing readiness early in the process may identify challenges and improve outcomes such as acceptability, appropriateness, and feasibility. This study examined changes in readiness and implementation outcomes among school staff implementing the Healthy School Start program in three Swedish municipalities M1, M2 and M3. Methods : Embedded in an implementation-effectiveness trial, validated questionnaires were used to assess readiness, acceptability (ACC), appropriateness (APP), and feasibility (FEAS) pre- and post-intervention. Data were collected from 39 school principals, 72 teachers, and 39 school nurses between September 2021 and May 2023. Summative scores were generated for each outcome using medians and interquartile ranges (IQR). Mixed-effects linear regressions were conducted to analyze change, adjusting for pre-intervention scores, professional group and clustering by school. Results : Adjusted analyses showed a significant increase in readiness post-intervention (β = 0.47, p < 0.001, 95% CI: 0.25–0.70) in the total sample. ACC, APP, and FEAS scores also increased significantly from pre- to post-intervention (ACC: β = 0.56, p < 0.001; APP: β = 0.45, p < 0.001; FEAS: β = 0.43, p = 0.001). While M3 showed significantly higher post-intervention readiness (β = 5.93, p = 0.014, 95% CI: 1.19–10.68) and FEAS compared to M1 (β = 2.67, p = 0.009, 95% CI: 0.67–4.66), no significant differences were found for ACC or APP between municipalities after adjustment. Across professional groups, school nurses reported lower feasibility pre-intervention compared to principals and teachers, but differences were not statistically significant after adjustment. Nearly half of participants in M2 scored in the “Low Readiness–Low Feasibility” quadrant, while over half in M1 and M3 scored in the “High Readiness–High Feasibility” quadrant. All M3 schools opted to continue the program into the subsequent year. Conclusion : This study provides novel empirical insight into school personnel’s preparedness to implement a new health program. Findings highlight that readiness and implementation outcomes can vary across settings, underscoring the need to address context-specific factors to strengthen implementation before starting the process. Trial registration: Registered prospectively at ClinicalTrials.gov ID: NCT04984421, registered July 30, 2021