Complementing random-digit-dial telephone surveys with other approaches to collecting sensitive data.

Surveys of sensitive topics, such as the Injury Control and Risk Surveys (ICARIS) or the Behavioral Risk Factors Surveillance System (BRFSS), are often conducted by telephone using random-digit-dial (RDD) sampling methods. Although this method of data collection is relatively quick and inexpensive, it suffers from growing coverage problems and falling response rates. In this paper, several alternative methods of data collection are reviewed, including audio computer-assisted interviews as part of personal visit surveys, mail surveys, web surveys, and interactive voice response surveys. Their strengths and weaknesses are presented regarding coverage, nonresponse, and measurement issues, and compared with RDD telephone surveys. The feasibility of several mixed mode designs is discussed; none of them stands out as clearly the right choice for surveys on sensitive issues, which implies increased need for methodologic research.