Structural barriers to social protection and HIV prevention services for sex workers in Southeast Asia: a fixed-effects panel data analysis, 2018-2025

IntroductionEmpirical evidence linking specific national structural policies to the provision of key HIV services in low- and middle-income settings remains scarce. This study addresses the research gap by quantifying the within-country relationships between six national structural policy indicators and the presence of the HIV prevention service component targeted at sex workers in Southeast Asia. MethodsWe constructed a balanced panel dataset covering eight Southeast Asian countries from 2018 to 2025 from the UNAIDS Global AIDS Monitoring (GAM) framework. We used Fixed-Effects (FE) and Random-Effects (RE) models to analyse the relationships, with the FE model selected as the more statistically appropriate estimator. We enhanced robustness by using clustered standard errors and one-period lagged explanatory variables. ResultsThe primary finding from the FE model indicated a statistically significant and positive contemporaneous association between the existence of legal or administrative barriers to social protection (barriers_spi,t) and the presence of HIV prevention services for sex workers ({beta} = 0.8531; p< 0.001). However, the robustness check revealed a statistically significant negative association between the two when using the lagged barrier variable (barriers_spi,t-1), suggesting a decline in HIV prevention service availability over time ({beta} = -0.3540; p < 0.05). We did not find any other policy variables coefficient to be statistically significant in the FE models. ConclusionsWhile the immediate recognition (contemporaneous effect) of structural barriers to access social protection may occur alongside prioritised HIV prevention service provision, the sustained presence of these impediments acts as a long-term constraint that undermines the effectiveness and sustainability of targeted HIV programmes. National HIV programmes must urgently prioritise the removal of structural barriers to ensure long-term service stability for key populations. Key MessagesO_LIWhat is already known on this topic: The global HIV response requires addressing structural determinants, such as legal barriers to social protection, to achieve epidemic control. However, there is a lack of robust empirical evidence linking the adoption of specific national structural policies to the actual availability of essential HIV services for key populations in low- and middle-income settings. C_LIO_LIWhat this study adds: This study provides the first evidence using FE panel data that the existence of national policy barriers to social protection is initially associated with a higher likelihood of having an HIV prevention service component for sex workers. The study also demonstrates that this positive association is short-lived, with the sustained presence of the barrier negatively impacting HIV prevention service availability for sex workers in the subsequent year. C_LIO_LIHow this study might affect research, practice or policy: Policymakers should recognise that simply identifying and reporting structural barriers, while perhaps coinciding with initial HIV prevention service investment, is insufficient for sustained policy intervention effectiveness. Policy should focus not just on the adoption of targeted programmes but on the urgent removal of structural barriers to ensure the long-term sustainability and success of prevention services for key populations. C_LI