IMPACT AND COST-EFFECTIVENESS OF DOXYCYCLINE POST-EXPOSURE PROPHYLAXIS FOR SEXUALLY TRANSMITTED INFECTIONS IN AUSTRALIAN MEN WHO HAVE SEX WITH MEN
Author(s)
Hao Lai, MPH1, Mingwang Shen, PhD1, Lei Zhang, PhD2.
1Xi'an Jiaotong University, Xi'an, China, 2Professor, Monash University, Melbourne, Australia.
1Xi'an Jiaotong University, Xi'an, China, 2Professor, Monash University, Melbourne, Australia.
OBJECTIVES: The World Health Organization (WHO) aims to reduce gonorrhoea and syphilis incidence by 90% and chlamydia by 50% by 2030 (compared to 2020). Doxycycline post-exposure prophylaxis (doxy-PEP) can reduce sexually transmitted infections (STIs) incidence, but potential antimicrobial resistance (AMR) raises concerns.
METHODS: We developed an individual-based stochastic network model simulating the transmission, progression, and treatment of gonorrhoea, chlamydia, and syphilis among an initial 10,000 men who have sex with men in Australia, incorporating demographic and behavioural factors, and AMR. Model calibration utilized annual STI incidence rates (2012-2022) from the Australian Collaboration for Coordinated Enhanced Sentinel Surveillance network and AMR trends (2015-2022) from the Melbourne Sexual Health Centre. A base case (no doxy-PEP) was compared to five doxy-PEP strategies (eligibility based on HIV/PrEP status and STI history) per Australian recommendations. Key outcomes included incidence of STI and gonorrhoea with high-level tetracycline resistance, quality-adjusted life-years gained, incremental cost-effectiveness ratios, and benefit-cost ratios. Strategies were also compared using a multi-criteria ranking framework.
RESULTS: We developed an individual-based model, calibrated to Australian national data, to compare five targeted doxy-PEP strategies with a base case from 2025 to 2034, using a multi-criteria ranking framework to evaluate their epidemiological, resistance, and economic outcomes. All evaluated strategies reduced STIs by 13.0% to 47.8% and were cost-saving. However, compared to the high 73.5% baseline projection for high-level tetracycline resistance by 2034, all strategies yielded higher proportions. This proportion was highest (97.4%) when targeting all HIV pre-exposure prophylaxis users, and lowest (81.2%) for the syphilis diagnosis strategy. This syphilis-focused strategy reduced overall STIs by 16.4%, had the highest benefit-cost ratio (9.2), and ranked highest in 9 of 11 evaluation frameworks.
CONCLUSIONS: Doxy-PEP is an effective, cost-saving intervention, with the syphilis diagnosis strategy representing the most recommended approach to optimally balance benefits and risks.
METHODS: We developed an individual-based stochastic network model simulating the transmission, progression, and treatment of gonorrhoea, chlamydia, and syphilis among an initial 10,000 men who have sex with men in Australia, incorporating demographic and behavioural factors, and AMR. Model calibration utilized annual STI incidence rates (2012-2022) from the Australian Collaboration for Coordinated Enhanced Sentinel Surveillance network and AMR trends (2015-2022) from the Melbourne Sexual Health Centre. A base case (no doxy-PEP) was compared to five doxy-PEP strategies (eligibility based on HIV/PrEP status and STI history) per Australian recommendations. Key outcomes included incidence of STI and gonorrhoea with high-level tetracycline resistance, quality-adjusted life-years gained, incremental cost-effectiveness ratios, and benefit-cost ratios. Strategies were also compared using a multi-criteria ranking framework.
RESULTS: We developed an individual-based model, calibrated to Australian national data, to compare five targeted doxy-PEP strategies with a base case from 2025 to 2034, using a multi-criteria ranking framework to evaluate their epidemiological, resistance, and economic outcomes. All evaluated strategies reduced STIs by 13.0% to 47.8% and were cost-saving. However, compared to the high 73.5% baseline projection for high-level tetracycline resistance by 2034, all strategies yielded higher proportions. This proportion was highest (97.4%) when targeting all HIV pre-exposure prophylaxis users, and lowest (81.2%) for the syphilis diagnosis strategy. This syphilis-focused strategy reduced overall STIs by 16.4%, had the highest benefit-cost ratio (9.2), and ranked highest in 9 of 11 evaluation frameworks.
CONCLUSIONS: Doxy-PEP is an effective, cost-saving intervention, with the syphilis diagnosis strategy representing the most recommended approach to optimally balance benefits and risks.
Conference/Value in Health Info
2026-09, ISPOR Asia Pacific 2026, Bangkok, Thailand
Value in Health, Volume 55, Issue S1
Code
EE66
Topic
Economic Evaluation
Disease
SDC: Infectious Disease (non-vaccine), SDC: Reproductive & Sexual Health