Background Few randomised controlled trials (RCTs) have been conducted to improve infant sleep practices. There is limited research on how best to integrate safe sleep information into routine paediatric anticipatory guidance delivered at well child visits (WCVs). This protocol paper describes the design of the Safe Start Study, which aims to evaluate the impact of safe sleep interventions on parents’ knowledge, beliefs and behaviours related to creating and maintaining a safe sleep environment for their infants.

Methods Safe Start is a three-group RCT comparing a safe sleep health education intervention delivered as part of the 2-week WCV, an attention-matched control group that receives a scald burn prevention intervention, and a standard of care group. A baseline survey is completed at the 2-week WCV; follow-up surveys and observations are completed in the home at 2–4 weeks and 2–3 months. Participants include mother–baby dyads attending a large urban paediatric primary care practice and their paediatricians. Primary outcomes are self-reported behaviours (baby sleeps alone, on back, in crib and in a smoke-free environment), observations of the sleep environment, paediatricians’ anticipatory guidance counselling about safe sleep and participants’ reported exposure to an existing city-wide safe sleep campaign.

Discussion Providing a theory-driven and evidenced-based safe sleep intervention is both a research and a clinical practice priority. This study will advance the application of educational and environmental interventions in the primary care setting to improve the safety of infant sleep environments in high-risk families.

Trial registration number NCT03070639; Pre-results.