Evaluating PrEP equity in Wales, UK, using triangulation of routine data sources

Unlike other key populations, gay, bisexual and other men who have sex with men (GBMSM) in Wales show a high uptake of HIV pre-exposure prophylaxis (PrEP), reflecting trends seen in countries where HIV incidence has historically been highest among GBMSM. Pragmatic solutions to evaluate inequity of uptake include the PrEP-to-need ratio (PnR), which was applied via the method and data triangulation approach to evaluate equity of PrEP uptake in Wales, 2023, using routine data.

PnR is redefined as the number of PrEP users divided by 'PrEP need'. Epidemiological PrEP need (represented by new HIV diagnoses) is compared with PrEP candidacy PrEP need (represented by the number of PrEP candidates among service users). PrEP candidates were retrospectively identified from the sexual health clinic (SHC) and online STI self-sampling request (Test and Post (T&P)) service users. PnRs were calculated across sociodemographic groups in Wales, 2023, and inequity ratios (magnitude of difference between two PnRs) were compared across methods.

In 2023, 2191 people were prescribed PrEP and 76 people received a 'first new HIV diagnosis'. Of 62 711 SHC users and 71 872 T&P users, 7% and 14%-28% were identified as PrEP candidates, respectively. Relative to PrEP need, there were 2-58 times more men than women and 2-35 times more people of White than Black ethnicity prescribed PrEP (ranges reflect variation across triangulated PrEP need denominators). Smaller inequities in uptake were identified, favouring people aged 55+ and those in urban and less deprived settings. SHC data generate smaller PrEP-candidacy rates than T&P, most notably for women and people of Black ethnicity, for whom estimates differ by a magnitude of up to 72 and 10, respectively.

This study identifies inequities in PrEP uptake across gender, ethnicity, age group, rural/urban classification and deprivation. Disparate estimates of equity gaps, most notably across gender and ethnicity, emphasise the limitations of routine data to evaluate equity of uptake. Data and method triangulation strengthen characterisation of PrEP-uptake inequities in low-incidence settings.