Participation bias in AIDS-related telephone surveys: Results from the national AIDS behavioral survey (NABS) non-response study

A study of nonrespondents from the National AIDS Behavioral Survey (NABS) was conducted in 1990 to attempt to identify potential differences in participants and non-participants that may influence estimates of sexual risk behavior Nonrespondents were comprised of two groups: people who refused twice to participate in the main study, and people who were extremely difficult to contact (i.e., could not be contacted within 17 call attempts). Demographic and social-psychological characteristics of these two groups were compared to those of main study participants. Results indicate that refusers are older attend church more often, are less likely to believe in the confidentiality of surveys, and have lower sexual self disclosure. Respondents who were contacted only after 18 or more calls show a different pattern of characteristics relative to main survey participants-they are overrepresented among men and Blacks, spend less time at home, and have more sexual partners. Correlational analyses suggest that the attributes of refusers tend to be related to lower sexual risk behavior while the characteristics of difficult-to-contact respondents are related to higher risk behavior.