Screening for HIV: systematic review to update the 2005 U.S. Preventive Services Task Force recommendation

Abstract

Background: A 2005 U.S. Preventive Services Task Force (USPSTF) review found good evidence that HIV screening is accurate and that antiretroviral therapy (ART) for immunologically advanced disease is associated with substantial clinical benefits, but insufficient evidence to determine the effects on transmission or in less immunologically advanced disease.

Purpose: To update the 2005 USPSTF review on benefits and harms of HIV screening in adolescents and adults, focusing on research gaps identified in the prior review.

Data sources: MEDLINE (2004 to June 2012) and the Cochrane Library (through the second quarter of 2012).

Study selection: Randomized trials and observational studies that compared HIV screening strategies and reported clinical outcomes, evaluated the effects of starting ART at different CD4 cell count thresholds and long-term harms, or reported the effects of interventions on transmission risk.

Data extraction: 2 authors abstracted and checked study details and quality using predefined criteria.

Data synthesis: No study directly evaluated the effects on clinical outcomes of screening versus no screening for HIV infection. A randomized trial and a subgroup analysis from a randomized trial found that ART initiation at CD4 counts less than 0.250 × 109 cells/L was associated with a higher risk for death or AIDS-defining events than initiation at CD4 counts greater than 0.350 × 109 cells/L (hazard ratios, 1.7 [95% CI, 1.1 to 2.5] and 5.3 [CI, 1.3 to 9.6]). Large, fair-quality cohort studies also consistently found that ART initiation at CD4 counts of 0.350 to 0.500 × 109 cells/L was associated with lower risk for death or AIDS-defining events than delayed initiation. New evidence from good-quality cohorts with longer-term follow-up confirms a previously observed small increased risk for cardiovascular events associated with certain antiretrovirals. Strong evidence from 1 good-quality randomized trial and 7 observational studies found that ART was associated with a 10- to 20-fold reduction in risk for sexual transmission of HIV.

Limitations: Only English-language articles were included. Observational studies were included. Studies done in resource-poor or high-prevalence settings were included but might have limited applicability to general screening in the United States.

Conclusion: Previous studies have shown that HIV screening is accurate, targeted screening misses a substantial proportion of cases, and treatments are effective in patients with advanced immunodeficiency. New evidence indicates that ART reduces risk for AIDS-defining events and death in persons with less advanced immunodeficiency and reduces sexual transmission of HIV.

Primary funding source: Agency for Healthcare Research and Quality.