Using interrupted time-series to measure the effects of criminal non-disclosure laws on HIV testing rates and incidence

An interrupted time-series design was used examining whether laws criminalizing non-disclosure of HIV-positive status affect HIV testing rates and incidence. Totals of monthly HIV tests, incidence, and at-risk/no-risk tests were collected in states with (California, New Jersey) and without criminal laws (control states). Aggregated totals from control states were used as successful control variables in MARIMA analyses. No changes were found in California. In New Jersey, total monthly tests increased by 530 (t = 2.360, p = .020) in the month of enactment of the law. Incidence decreased by 21 cases (t = -2.772, p = .007) at 6 month, and by 18 cases (t = -2.460, p = .016) at 12 months following enactment of the law. Monthly tests for no-risk persons decreased by 30 tests (t = -2.113, p = .037) on month of enactment, by 38 tests (t = -2.994, p = .004) at 6 month, and 41 tests (t = -3.422, p = .001) at 12 months following enactment of the law. Models had adjusted- R²'s of .472 to .874, graphically fit the data well, and yielded white noise residuals. These findings indicate that while more people are being tested, fewer people actually participating in risk behavior are testing. Also, fewer individuals at no-risk are being tested. Overall, people may become more cautious about learning their HIV-status following the passage of the law. Uniform collection, management, and accessibility of HIV testing data are prerequisite to more comprehensive studies of effects of law and policy on testing.