Data collection for sexually transmitted disease diagnoses: a comparison of self-report, medical record reviews, and state health department reports.

Purpose: To compare three methods of data collection on case ascertainment of past chlamydia or gonorrhea diagnoses.
Methods: Data collection for 361 adolescent females between 1998 and 2000 included: 1) face-to-face interviews; 2) computerized and paper medical record reviews; and 3) chlamydia and gonorrhea reports to the state health department. Statistical methods include latent class and composite reference standard analyses.
Results: The estimated prevalence of past diagnoses did not differ significantly by data collection method for chlamydia (20.5%, 23.0%, and 19.7% by self-report, medical record reviews, and state health department reports, respectively) or gonorrhea (4.7%, 6.9%, and 5.5%, respectively) during the 2-year study period. The estimated latent class and composite reference standard prevalences for chlamydia were 23.5% and 26.9%, respectively (p=.04 and p < .01 for differences from self-report alone, respectively). For gonorrhea, the estimated latent class and composite reference standard prevalences were 7.8% and 6.9%, respectively (p < .01 for both differences from self-report alone). Kappa scores for self-report compared with the latent class and composite reference standard prevalences ranged from .67 to .80, and the magnitude of under-reporting ranged from 21% to 47%.
Conclusions: The similar case ascertainment from the three sources separately and high reliability of self-report, coupled with its feasibility and low cost, suggest that self-report is a viable data collection method for STD diagnoses. However, using multiple sources may be preferable when time and resources permit given that under-reporting by self-report is likely to occur (particularly for gonorrhea) and that greater case ascertainment can be achieved.