The prevalence of HIV pre-exposure prophylaxis (HIV-PrEP) use and HIV-PrEP-to-need ratio in nine Canadian provinces, 2018-2021.

Background: Measuring trends in HIV pre-exposure prophylaxis (HIV-PrEP) uptake is important to inform planning for prevention programs and policies. The HIV-PrEP-to-need ratio (PnR) is a construct used by public health organizations to explore disparities in the provision of HIV-PrEP across geographic areas and demographic categories (e.g., age, sex).

Methods: This is a retrospective database review study using administrative pharmacy data, containing limited demographic information, from nine Canadian provinces. Annual estimates of persons taking HIV-PrEP and PnR were generated using data from the company IQVIA and the BC Centre for Excellence on HIV/AIDS. Data on new HIV diagnoses were obtained from the National HIV Surveillance System. The PnR was defined as the number of HIV-PrEP users divided by the number of new HIV diagnoses annually and is interpreted as the number of HIV-negative people using HIV-PrEP each year for every person newly diagnosed with HIV.

Results: In 2021, an estimated 23,644 individuals were prescribed HIV-PrEP, corresponding to an HIV-PrEP prevalence of 66.9 per 100,000 persons. This represents a 1.8-fold increase since 2018. The overall PnR was 16.8, meaning that for every person newly diagnosed with HIV, 17 HIV-negative individuals were taking HIV-PrEP. There were disparities between provinces (PnR range: 1.5/100,000-37.7/100,000) and between males and females (PnR 22.6 and 1.2, respectively). Females, individuals aged 0-19 years, and those in Manitoba, Saskatchewan and Prince Edward Island, had lower levels of HIV-PrEP use relative to epidemic need.

Conclusion: In Canada, the use of HIV-PrEP increased from 2018 to 2021 and uptake varied by age, sex and province. HIV-PrEP-to-need ratio is a useful measure to assess uptake of HIV-PrEP as a prevention strategy and could be used to explore disparities in provision across provinces and available demographic categories. However, PnR could be improved with more information on key populations and other attributes, such as race/ethnicity, socioeconomic status and residence of city/rural area.