Sampling Methods Because it would be impossible to phone every household in the state each year, BRFSS relies on a sample of the population. The sampling method used assures comparability of data across states and over time. Most states use the Disproportionate Stratified Sample (DSS) Method. Phone numbers are randomly selected throughout the state. Business and nonworking numbers are omitted. Individuals age 18 years and older are randomly selected from each household called. Page 1 of 3