Estimated HIV Inter-test Interval Among People at High Risk for HIV Infection in the U.S.

INTRODUCTION: Knowing the HIV testing frequency and its temporal changes are central to evaluate public adherence to HIV testing recommendations and performance of HIV prevention programs. This study intended to estimate the mean HIV inter-test interval (ITI) and monitor its trends among men who have sex with men (MSM); people who inject drugs (PWID); and high-risk heterosexuals (HRH).

METHODS: Using National HIV Behavioral Surveillance data collected during 2008-2015, this analysis estimated the mean HIV ITI for each year by race/ethnicity and age among MSM, PWID, and HRH who reported the most recent HIV test date. Separate statistical models based on renewal process theory were fit using PROC NLIN with Newton-Raphson method. Estimated mean HIV ITI lengths were compared using the z-test.

RESULTS: Estimated HIV ITI generally decreased in the past decade among MSM, PWID, and HRH who reported the most recent HIV test date. In most recent study years, estimated HIV ITI (in months) ranged from 5.8 to 12.5 among MSM, from 9.0 to 13.1 among PWID, and from 15.3 to 26.7 among HRH. Within each risk group, estimated HIV ITI was shortest among blacks and individuals aged 18-24 years.

CONCLUSIONS: People at high risk for HIV infection who ever tested for HIV tested more frequently in the past decade. Most recently, MSM and PWID largely adhered to the Centers for Disease Control and Prevention's HIV testing recommendations, but HRH tested less frequently. Identifying factors associated with infrequent testing among HRH may provide information for future HIV testing initiatives.