Recent decline in the incidence of human immunodeficiency virus infection among California men who have sex with men.

Monitoring the incidence of human immunodeficiency virus (HIV) infection among men who have sex with men (MSM) is imperative for developing targeted prevention programs and evaluating their effectiveness. The authors used California counseling and testing data to estimate the temporal trend in HIV incidence among MSM in California. HIV incidence rates were retrospectively calculated among MSM who had received at least 1 HIV test at a public California counseling and testing site between 1997 and 2007 and had a prior HIV-negative test from any HIV testing source. All study subjects were weighted on the basis of the interval between the last HIV-negative test and the current HIV test to account for the right-truncation bias introduced by more frequent testers. The authors observed that the HIV incidence rate among MSM in California increased from 2.0/100 person-years (95% confidence interval (CI): 1.8, 2.2) in 1997 to 2.4/100 person-years (95% CI: 2.2, 2.6) in 2003 and then decreased to 1.9/100 person-years (95% CI: 1.7, 2.0) in 2006. Trend analyses showed that both the increase (P < 0.001) and the decrease (P < 0.01) were statistically significant. The study showed that HIV incidence among MSM in California had decreased since 2003.

Matching AIDS and tuberculosis registry data to identify AIDS/tuberculosis comorbidity cases in California.

The purpose of this study was to evaluate the sensitivity and positive predictive value (PPV) of a registry data linkage procedure used in the California AIDS and Tuberculosis (TB) Registry Data Linkage Study to identify AIDS/TB comorbidity cases in California. The California AIDS registry data from 1981 to 2006 were linked to the California TB registry data from 1996 to 2006 using LinkPlus, a probabilistic record linkage program developed by the Centers for Disease Control and Prevention, and matched results were manually reviewed to determine true or false matches. We estimated the sensitivity of this procedure to range from 98.0 per cent (95% confidence interval, CI: 97.3%, 98.7%) to 98.8 per cent (95% CI: 98.1%, 99.2%), and the PPV to be 100 per cent (95% CI: 96.8%, 100.0%). Our study demonstrated the feasibility of using this linkage procedure to match AIDS and TB registry data with a very high degree of accuracy.