Response bias in assessing sexual behaviors relevant to HIV transmission

Survey questions often probe respondents for quantitative facts about events in their past: "During the last 2 weeks, on days when you drank liquor, about how many drinks did you have?" "During the past 12 months, how many visits did you make to a dentist?" "When did you last work at a full-time job?" are all examples from national surveys. Although questions like these make an implicit demand to remember and enumerate specific autobiographical episodes, respondents frequently have trouble complying because of limits on their ability to recall. In these situations, respondents resort to inferences that use partial information from memory to construct a numeric answer. Results from cognitive psychology can be useful in understanding and investigating these phenomena. In particular, cognitive research can help in identifying situations that inhibit or facilitate recall and can reveal inferences that affect the accuracy of respondents' answers.

Published reports describing behavioral changes in response to the threat of AIDS (acquired immunodeficiency syndrome) are reviewed. These studies demonstrate rapid, profound, but expectably incomplete alterations in the behavior of both homosexual/bisexual males and intravenous drug users. This is true in the highest risk metropolitan areas such as New York City and in areas with lower AIDS incidence. Risk reduction is occurring more frequently through the modification of sexual or drug-use behavior than through its elimination. In contrast to aggregate data, longitudinal descriptions of individual behavior demonstrate considerable instability or recidivism. Behavioral change in the potentially vulnerable heterosexual adolescent and young adult populations is less common, as is risk reduction among urban minorities. Reports of AIDS-related knowledge and attitudes generally parallel the pattern of behavioral changes. Nonetheless, few studies investigate the relationship of knowledge and attitudes to risk reduction. Future studies should provide much-needed information about the determinants as well as the magnitude of behavioral changes required to reduce the further spread of AIDS.