Novel metric for evaluating pre-exposure prophylaxis programme effectiveness in real-world settings.

Area of Science:

• Public Health
• Epidemiology
• HIV Prevention

Background:

• Large-scale provision of HIV pre-exposure prophylaxis (PrEP) is expanding globally.
• Current methods for evaluating PrEP scale-up effectiveness rely on clinical trials or models, lacking real-world applicability.
• A systematic approach is needed to compare diverse PrEP implementation strategies.

Purpose of the Study:

• To propose a novel, pragmatic metric for evaluating and comparing PrEP program effectiveness using routine implementation data.
• To demonstrate the application of this metric using South African and Zambian PrEP guidelines.
• To establish a consistent method for measuring PrEP program success in real-world settings.

Main Methods:

• Developed a metric incorporating HIV seroconversion, variable HIV risk (seasons of risk), and PrEP use persistence.
• Defined success criteria: no seroconversion, limited high-risk periods off PrEP, and consistent healthcare engagement or informed discontinuation.
• Calculated a PrEP success ratio by comparing successful outcomes to total initiators.

Main Results:

• The proposed metric provides a consistent way to measure PrEP program effectiveness with routinely collected data.
• Examples from South Africa and Zambia illustrate the metric's practical application.
• The success ratio is an easily interpretable measure for monitoring and comparing PrEP programs.

Conclusions:

• The novel metric enables effective evaluation and comparison of PrEP scale-up strategies using routine data.
• This approach can inform cost-effectiveness analyses and guide improvements in PrEP service delivery.
• Widespread adoption will facilitate comparative studies of different PrEP program models.