Effectiveness of a risk-based visitor-prioritizing system at a sexually transmitted infection outpatient clinic

Objective: The objective of this study was to study the efficacy/effectiveness of a risk-based visitor-prioritizing system at a sexually transmitted infection (STI) clinic aimed to improve screening capacity by providing tailored service. Study Design: In April 2004, a prioritizing system was implemented that classifies visitors as high or low risk depending on reported sexual behavior and previous STI events. The high- and low-risk groups are assigned to standard and short screening protocols, respectively. Both protocols include diagnostic testing for syphilis, urogenital gonorrhea, chlamydia, and optional for HIV. To assess the effectiveness of the system, differences in prevalence of STI diagnoses in the standard and short protocol were analyzed by chi(2) test. Results: In total, 14,391 visitors (64%) received standard screening and 8,056 visitors (36%) received short screening. The STI prevalence in both groups was 18.1% and 7.6%, respectively (P <0.001); prevalence of HIV was 1.8% and 0.3%, respectively (P <0.001). The sensitivity of the prioritizing system was 74%. Specificity was substantially lower (42%). Conclusions: This prioritizing system is effective in differentiating between visitors at high and low risk for STI, contributing to provision of tailored STI service, increasing efficiency, and client access to STI service.