Sample size calculation
Approximately 500 services were expected to provide post-intervention data, to allow for approximately 165 services per arm (assuming that response rates are equally distributed across the three arms) included in the evaluation. For the primary outcome (the proportion of services adopting the Guidelines regarding indoor-outdoor play for the full day and more time outdoors), 165 childcare services per arm was calculated to detect difference in service Guideline adoption of 14.2%, based on previous data indicating that 62.3% of ECEC services had adopted an indoor-outdoor program [