Modeling Sources of Self-Report Bias in a Survey of Drug use Epidemiology

Purpose: Well-documented errors in the reporting of drug-related behaviors have been attributed to several sources. These include: 1) respondent difficulties in understanding survey questions, 2) problems in recalling the information necessary to accurately answer these questions, and 3) social pressures that discourage accurate reporting. We report covariance structure models designed to simultaneously evaluate each of these potential sources of error.

Methods: Data examined are from a community survey of 627 Chicago adults which collected drug use self reports (via ACASI technology), multiple biological samples (including hair, urine, and saliva) that permit self-report validation, and a series of probes designed to collect systematic information regarding respondent comprehension and memory difficulties and social desirability concerns. These three sets of information were employed to construct latent variable covariance structure models that enabled an evaluation of the effects of each potential source of reporting error on the quality of drug use reporting.

Results: Social desirability concerns were predictive of discordant drug use reporting and drug use under-reporting. Memory difficulties were predictive of drug use over-reporting. Differences in the predictive power of these variables were found across race/ethnic groups.

Conclusions: Both memory difficulties and social desirability concerns are independent sources of measurement error in surveys of drug use epidemiology.