An audit of the use of definitions of sudden infant death syndrome (SIDS).

Given that there are a number of contradictions in the SIDS literature and that the definition of SIDS that was relied upon to authenticate cases in reports is not always specified, an audit of publications was undertaken. Fifty papers dealing with SIDS that were published in 2005 were reviewed. The majority (58%) of reports had either not specified a definition of SIDS, or had used non-standard or idiosyncratic definitions. Of the papers that had documented a definition: 30% used the 1989 NICHD definition, 10% used the 2004 San Diego definition, and 2% used the 1969 Seattle definition. Failure to use standard published definitions of SIDS and/or to clearly specify the definition that has been followed may severely hamper the evaluation of SIDS research.