Article type
Year
Abstract
Introduction:
Objectives: This is the first annual update of the Centers for Disease Control and Prevention's (CDC) Prevention Research Synthesis project. This project was initiated in 1996 to conduct systematic reviews to assess the effectiveness of HIV prevention interventions.
Methods: The original project report had 46 methodologically rigorous studies; another 17 were added for this update. Refinements were made such as accounting for intra-class correlations (k=18). Further, whereas the condom use outcome was measured previously, the update added three behavioral outcomes (unprotected sex, number of sex partners, sexual risk index) and one biological outcome (STD/HIV incidence). Framing the outcome with a broader construct, "sexual risk reduction," allowed selection of one outcome per study based on a pre-established hierarchy of outcomes. Summary effects, representing the difference in outcomes between the intervention and the control/comparison group, were determined with a random effects model. Stratified analyses examined factors associated with study design (e.g., random v. non-random assignment), population (e.g., age), setting (e.g., clinic v. non-clinic), and intervention factors (e.g., content and methods).
Results: Sensitivity analysis showed no significant difference in effects between the construct and three of the separate outcomes. The summary effects remained stable over time, and were positive and significant (odds ratio for sexual risk reduction: .79) (confidence interval .72, .87) (k=63). In this update, study design and population factors remained significant; also, newly coded intervention factors contributed to results.
Discussion: l)Updating an HIV intervention database contributes to the ability to observe intervention effects. 2) As more studies become available, additional variables can be considered in the analyses and thereby increase understanding of the conditions associated with effectiveness. 3) Providers of HIV prevention programs need to utilize this knowledge of conditions as the deliver prevention services.
Objectives: This is the first annual update of the Centers for Disease Control and Prevention's (CDC) Prevention Research Synthesis project. This project was initiated in 1996 to conduct systematic reviews to assess the effectiveness of HIV prevention interventions.
Methods: The original project report had 46 methodologically rigorous studies; another 17 were added for this update. Refinements were made such as accounting for intra-class correlations (k=18). Further, whereas the condom use outcome was measured previously, the update added three behavioral outcomes (unprotected sex, number of sex partners, sexual risk index) and one biological outcome (STD/HIV incidence). Framing the outcome with a broader construct, "sexual risk reduction," allowed selection of one outcome per study based on a pre-established hierarchy of outcomes. Summary effects, representing the difference in outcomes between the intervention and the control/comparison group, were determined with a random effects model. Stratified analyses examined factors associated with study design (e.g., random v. non-random assignment), population (e.g., age), setting (e.g., clinic v. non-clinic), and intervention factors (e.g., content and methods).
Results: Sensitivity analysis showed no significant difference in effects between the construct and three of the separate outcomes. The summary effects remained stable over time, and were positive and significant (odds ratio for sexual risk reduction: .79) (confidence interval .72, .87) (k=63). In this update, study design and population factors remained significant; also, newly coded intervention factors contributed to results.
Discussion: l)Updating an HIV intervention database contributes to the ability to observe intervention effects. 2) As more studies become available, additional variables can be considered in the analyses and thereby increase understanding of the conditions associated with effectiveness. 3) Providers of HIV prevention programs need to utilize this knowledge of conditions as the deliver prevention services.