An ecological analysis of legal policy environments and reported pre exposure prophylaxis availability for key populations in Asia Pacific countries

This study aims to assess how national laws and policies affecting key populations relate to Pre-Exposure Prophylaxis (PrEP) availability across 40 Asia‑Pacific countries. We use a cross‑national ecological design and secondary UNAIDS data to quantify legal vulnerability and its association with PrEP programme presence and scale. A quantitative ecological analysis was conducted using secondary data submitted by 40 Asia–Pacific countries to UNAIDS. Country-level indicators related to laws, legal protection rights, and participation of KPs in the development of HIV-related policies were extracted. Twenty-two indicators across four key populations—People Who inject Drugs (PWID: 7), female sex workers (FSWs: 4), transgender people (transgender people: 6), and men who have sex with men (MSM: 5)—were used to generate cumulative legal–policy scores for each country. Countries were categorised by reported PrEP availability (available, not available, or not reported). One-way analysis of variance (ANOVA) assessed differences in mean scores across groups, with Bonferroni post-hoc tests. Among the 40 countries, 12 reported PrEP availability, 14 reported non-availability, and 14 did not report PrEP status. Mean cumulative legal–policy scores (maximum = 22) were 8.92, 10.07, and 1.71, respectively. ANOVA showed statistically significant differences across groups, driven primarily by countries with non-reported PrEP data. This ecological analysis suggests that non-reporting of PrEP and legal–policy indicators emerged as a structurally suggestive signal, pointing to possible links with unfavourable legal contexts and limited prevention readiness rather than neutral data gaps.