Two one-step methods for household screening and interviewing using random digit dialing

Random digit dialing is commonly used to select controls for epidemiologic studies. The traditional method of random digit dialing entails screening households to obtain a pool of eligible subjects and then selecting a random sample to serve as controls. Two random digit dialing methods are described in which household screening and interviewing are combined into one step. The advantages and limitations associated with both of the one-step methods and the traditional two-step approach are discussed.