Each month a stratified sample of approximately 155 mothers is randomly selected from recent Wisconsin birth certificates. An introductory letter is mailed to each woman in the sample two to four months after the baby's birth. The PRAMS survey is mailed a few days later.
A reminder letter and a second package is mailed to mothers who do not respond. Mothers who still do not respond are telephoned to attempt to complete an interview.
Wisconsin PRAMS began mailing surveys to sampled mothers in May 2007. PRAMS materials are available in both English and Spanish.
Detailed information about PRAMS is available from the Centers for Disease Control and Prevention.