BACKGROUND: Previous analyses have demonstrated cost-effective screening frequencies for men who have sex with men and people who inject drugs. However, it is less clear how often heterosexuals (HETs) should be screened, particularly those at high risk of HIV.
METHODS: We applied the HOPE model, a dynamic compartmental model of the HIV epidemic, to examine HIV screening at various frequencies for the mutually exclusive general HET and high-risk HET populations. The model examines HIV progression and transmission in the US population aged 13-64, stratified into 195 subpopulations based on HIV transmission risk, risk level and demographic characteristics. It includes 25 compartments defined by HIV disease and continuum-of-care stages. The general HET population was defined as HETs who were sexually active within the past 12 months. High-risk HETs were defined as HETs living in urban, high-poverty, white-minority areas with high HIV prevalence. Symptomatic testing was considered in addition to screening. The model captures the benefits of HIV screening through changes in risk behavior upon diagnosis and viral suppression from antiretroviral therapy. Model outcomes from 2016-2035 include HIV incidence and prevalence, discounted costs and quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs).
RESULTS: When screening the general HET population every 20 years, screening high-risk HETs as frequently as annually was cost-effective with an ICER of $63,200 per QALY gained compared to screening high-risk HETS at 3-year intervals. Screening high-risk HETs every 6 months, compared to annually, yielded an ICER of $129,400 per QALY gained (figure). More frequent testing for the general HET population costs $310,000 - $1.5 million per QALY gained for 10-year to 3-month screening intervals (data not shown). Screening high-risk HETs annually compared to every 20 years reduced projected cumulative HIV incidence for the total population by 5%. Our findings were robust to a 20% variation in key parameters including per-act HIV transmission risks, testing compliance, test sensitivity, probability of viral suppression and costs.
CONCLUSIONS: Screening high-risk HETS is cost-effective when conducted annually and could be considered economically attractive at 6-month intervals. HIV screening of the general HET population was beyond accepted thresholds of cost-effectiveness when conducted more frequently than 20-year intervals.
