Iritani, B. J.
; Ford, C.A.; Miller, W.C.; Hallfors,D.D.
; and Halpern, C. Sexual Health
, vol. 3, pgs. 245-51 (2006)Background: Many studies rely on respondent reports of prior diagnosed sexually transmissible infections (STIs), but these self reports are likely to under-estimate infection prevalence. The extent of bias from using self-reported STI data, and whether bias varies by sex and race, is largely unknown. This gap is addressed using a large, nationally representative sample.
Methods: Cross-sectional analyses of Wave III of the National Longitudinal Study of Adolescent Health. Participants were 18-26 years old (n = 12 359). Estimates of the prevalence of chlamydial infection based on self-reported diagnoses in the past year were compared with actual prevalence based on nucleic acid amplification testing (NAAT) at the time of data collection. Ratios of test-identified prevalence to self-reported diagnosis prevalence were calculated by sex and race/ethnicity groups. Larger ratios indicate greater extent of self reports under-estimating infection prevalence.
Results: About 4.2% of the sample had a current NAAT-identified chlamydial infection, but only 3.0% reported having been diagnosed with chlamydia in the past year, yielding a ratio of 1.43. The ratio of test-identified infection prevalence to prevalence identified from self-reported diagnoses was larger among men than women (2.07 versus 1.14, P < 0.05). Among men, the ratio was larger among non-Hispanic blacks (2.40) compared with non-Hispanic whites (1.07, P < 0.05).
Conclusions: Use of self-reported diagnoses under-estimates chlamydial infection prevalence, particularly among men, and among non-Hispanic black men. Reliance on self-reported STIs may consequently lead to biased conclusions, particularly for these groups. Use of biological testing for STIs in research studies is recommended.