HIV / STI
Assessing the link between long-acting contraception and risk of sexually transmitted blood-borne infections Haylie Simmons* Nichole Austin Farhan Khandahar
Background: Chlamydia and gonorrhea rates are surging across Canada, and people under 25 (particularly adolescent girls/ young women) are at increased risk. As disease incidence climbs, so does the promotion of long-acting reversible contraception (LARC) like intrauterine devices (IUDs). LARCs do not protect against sexually transmitted blood-borne infections (STBBIs), and LARC users are less likely to use secondary forms of contraception (e.g., barrier methods). This may put LARC users at increased risk of STBBIs.
Methods: We conducted a systematic review of evidence on LARC use and incident STBBIs (as defined by the Public Health Agency of Canada). Search engines included Medline, Embase, and CINAHL. We produced a narrative synthesis and a random effects meta-analysis (in progress) to summarize our findings; publication bias and study heterogeneity were assessed using funnel plots and I2 values. We adhered to PRISMA 2020 reporting guidelines. This review was preregistered in Prospero.
Results: Our initial search yielded 898 studies, 45 of which met our inclusion criteria. Approximately 44% focused primarily on chlamydia and/or gonorrhea; the remaining 56% assessed incident HIV (26%), HPV (18%), and other /aggregated STBBIs (12%). Sub-Saharan Africa was the most common location (~38%); there were no Canadian studies. Designs were mainly observational with very few (n=2) examining LARC/STBBI associations specifically among adolescents/young adults. Evidence on the association between LARC use and STBBI risk was strikingly contradictory, with roughly half reporting increased STBBI risk among LARC users and half pointing toward a null or protective association.
Conclusions: Our findings underscore the need for additional high-quality research on LARC use and STBBI risk given contemporary trends in contraception, particularly among younger people. Differences in study design and analysis likely obscure the true relationship between LARCs and STBBI risk.