Development and validation of the Safe Sleep Calculator to assess risk of sudden unexpected death in infancy.

We describe the development and validation of a Sudden Unexpected Death in Infancy (SUDI) risk assessment clinical tool. An initial SUDI risk assessment algorithm was developed from an individual participant data meta-analysis of five international SIDS/SUDI case-control studies. The algorithm was translated into a clinical web tool called the Safe Sleep Calculator, which was tested at the routine infant 6-week check-up in primary care clinics in New Zealand. Evidence was gathered through mixed-methods research to inform the revision of the algorithm and the clinical tool. The revised algorithm performance was validated on a new contemporary New Zealand SUDI case-control study dataset and the pilot population data set. The area under the Receiver Operator Characteristic (ROC) curve is 0.89, with a sensitivity of 83.0% and a specificity of 80.9% in the NZ infant population when 0.3 per 1000 live births or more risk is used to define 'at higher risk'. The Safe Sleep Calculator SUDI risk assessment tool provides individualized evidence-based specific SUDI prevention advice for every infant and enables the concentration of additional SUDI prevention efforts and resource for infants at higher risk.