Contributions of underlying factors and programs to the HIV decline in Zimbabwe.

Form(s) of evidence supporting conclusion: M, epidemiological modeling; QN, survey or other quantitative data; P, program data; QL, qualitative data. See Text S1 for details.aExtent to which change in the factor concerned is likely to effect behavior change, and thereby reduce HIV transmission at the population level.bExtent to which the intervention was scaled-up during the period of most rapid reduction in risk as determined by the epidemiological modeling assessment (i.e., about 1999–2003).cBehavior change programs as a whole probably contributed to reducing HIV risk but, given the limitations in the available data, it was not possible to isolate the contributions (if any) of each individual program area.“?” indicates greater uncertainty.