Poor criterion validity of self-reported hepatitis B infection and vaccination status among injecting drug users: a review.

Issues: Limited resources may dictate the use of self-reported hepatitis B virus (HBV) status to determine the need for testing and/or vaccination in resource-poor settings, as well as in research and surveillance.

Approach: A synthesis of the literature on the criterion validity of self-reported HBV infection and vaccination history among injecting drug users (IDU) in order to determine the utility or otherwise of self-reports in this area.

Key Findings: The degree of agreement between self-reported and serological HBV status is consistently poor among IDU. In previous research, 46-95% of IDU with serological evidence of exposure to HBV did not report a history of infection, and serological evidence of vaccine-conferred immunity was not detected among 50-73% of IDU who reported being vaccinated.

Implications: A lack of awareness or misapprehension about their HBV status may lead some IDU to inadvertently engage in behaviours which place their injecting and sexual partners at risk, contributing to the continued potential for high incidence of HBV infection among this population.

Conclusion: Self-reported histories should not be used in lieu of serological testing when assessing infection history or immunisation status. Poor criterion validity also indicates that self-reports of HBV infection status should not be used to estimate the prevalence and incidence of this infection. Due to their low sensitivity, self-reports of HBV infection should at best be considered only as a lower bound prevalence estimate.