A Reevaluation of the Voluntary Medical Male Circumcision Scale-Up Plan in Zimbabwe

Abstract

Background: The voluntary medical male circumcision (VMMC) program in Zimbabwe aims to circumcise 80% of males aged 13-29 by 2017. We assessed the impact of actual VMMC scale-up to date and evaluated the impact of potential alterations to the program to enhance program efficiency, through prioritization of subpopulations.

Methods and findings: We implemented a recently developed analytical approach: the age-structured mathematical (ASM) model and accompanying three-level conceptual framework to assess the impact of VMMC as an intervention. By September 2014, 364,185 males were circumcised, an initiative that is estimated to avert 40,301 HIV infections by 2025. Through age-group prioritization, the number of VMMCs needed to avert one infection (effectiveness) ranged between ten (20-24 age-group) and 53 (45-49 age-group). The cost per infection averted ranged between $811 (20-24 age-group) and $5,518 (45-49 age-group). By 2025, the largest reductions in HIV incidence rate (up to 27%) were achieved by prioritizing 10-14, 15-19, or 20-24 year old. The greatest program efficiency was achieved by prioritizing 15-24, 15-29, or 15-34 year old. Prioritizing males 13-29 year old was programmatically efficient, but slightly inferior to the 15-24, 15-29, or 15-34 age groups. Through geographic prioritization, effectiveness varied from 9-12 VMMCs per infection averted across provinces. Through risk-group prioritization, effectiveness ranged from one (highest sexual risk-group) to 60 (lowest sexual risk-group) VMMCs per infection averted.

Conclusion: The current VMMC program plan in Zimbabwe is targeting an efficient and impactful age bracket (13-29 year old), but program efficiency can be improved by prioritizing a subset of males for demand creation and service availability. The greatest program efficiency can be attained by prioritizing young sexually active males and males whose sexual behavior puts them at higher risk for acquiring HIV.

Fig 1. Projected outcomes of age-group prioritization.

A) Number of voluntary medical male circumcisions (VMMCs) needed to avert one HIV infection (effectiveness) by 2025. B) Cost per HIV infection averted by 2025 (cost-effectiveness). C) Projected incidence rate reduction throughout the years up to 2045. The results are for 80% VMMC coverage by 2017 in each of the prioritized age band.

Fig 2. Program efficiency and policy domains of age-group prioritization in the voluntary medical male circumcision (VMMC) program.

A) Expansion path curve showing the incremental change in total cost of the VMMC program (program cost) relative to the incremental change in total number of HIV infections averted (magnitude of impact) for each age group- targeted scenario. The blue line shows the expansion of the program with minimal diminishing of returns, and the red line shows the expansion of the program with considerable diminishing of returns. B) Frontier policy plot delineating the different policy domains based on the theme of maximizing program efficiency (maximizing gain while minimizing cost). Circle size represents the total number of HIV infections averted (magnitude of impact). C) Frontier policy plot delineating the different policy domains based on the theme of maximizing the total impact of the VMMC program. Circle size represents the total number of VMMCs needed. In both B and C, the orange circles represent the age brackets that fit into the optimal policy domain, the red circles represent Zimbabwe’s current targeted age group (13–29 year old males), and the blue circle represents the baseline VMMC intervention scenario. * Gain/Pain index: the proportional reduction in the total number of infections averted (Gain) over the proportional reduction in the total VMMC program cost (Pain). These proportions are assessed relative to the baseline scenario of targeting males aged 15–49 years.

Fig 3. Projected outcomes of geographic and sexual risk-group prioritization.

A) Number of voluntary medical male circumcisions (VMMCs) needed to avert one HIV infection (effectiveness) by 2025 through geographic prioritization. B) Number of VMMCs needed to avert one HIV infection by 2025 through risk-group prioritization. C) Expansion path curve showing the incremental change in total cost of the VMMC program relative to the incremental change in total number of HIV infections averted for each sexual risk-group targeted scenario. The blue line shows the expansion of the program with minimal diminishing of returns, and the red line shows the expansion of the program with considerable diminishing of returns.

Fig 4. Range of uncertainty for the number of voluntary medical male circumcisions (VMMCs) needed to avert one HIV infection by 2025 for the different prioritized age groups.

The solid red line represents the point estimate curve. The dashed lines bracket the 95% uncertainty interval of the curves generated in the uncertainty analyses.