The Family Health Survey sampling frame consists of all Wisconsin households with a working landline telephone. In 2008, the sample design for selecting telephone numbers for the survey divided the state into eight sample strata, seven of which were defined geographically. Five strata were comprised of regional county groupings and two strata were defined as Dane and Brown counties. Telephone area code/prefix combinations from these seven strata were randomly sampled at varying rates, designed to provide a useable sample for several parts of the state. An eighth sample stratum consisted of telephone prefixes that had previously been found to.
