LONG-ACTING REVERSIBLE CONTRACEPTIVES AND THE RISK OF SEXUALLY TRANSMITTED BLOOD-BORNE INFECTIONS AMONG CANADIANS UNDER 25 YEARS OF AGE

Abstract

The incidence of sexually transmitted blood-borne infections (STBBIs), specifically chlamydia and gonorrhea, is surging across Canada. Prevention efforts for STBBIs center on the use of barrier methods (e.g., condoms). However, barrier methods are prone to user error and have high failure rates of preventing pregnancy compared to long-acting reversible contraceptives (LARC) such as intrauterine devices (IUDs). Yet, LARC methods do not offer any protection against STBBIs. Given their effectiveness as a contraceptive, use of LARC methods is increasingly recommended by providers for young women. Young women are also disproportionately impacted by rising chlamydia and gonorrhea rates. There is currently little research on the association between increased LARC use and the increase of STBBIs within Canada, which ultimately translates to an important knowledge gap. First, I conducted a policy scan to document provincial variation in LARC coverage across Canada. Second, I assessed the population-level impact of expanded LARC access on chlamydia/gonorrhea incidence among people 15-24 years old. I used a policy that expanded LARC access at the population level in Ontario (known as OHIP+) as a proxy for increased use of LARCs (through increased access). I then estimated the population-level impact of expanded LARC access on chlamydia/gonorrhea incidence using difference-in-differences (DiD) approach and a negative binomial regression analysis. Ontario was selected as the exposed group, and British Columbia (where no change in access occurred) as the unexposed. The outcome of interest was chlamydia/gonorrhea incidence among people aged 15-24 years old and data was provided by Public Health Ontario and The BC Centre for Disease Control. The policy scan found that all provinces had some level of LARC coverage for targeted sub-populations such as low-income families with strict eligibility guidelines. Prior to 2023, few provinces had broad coverage plans with minimal eligibility criteria like OHIP+. The policy scan also confirmed BC was an adequate comparator group for the DiD analysis. I found following the OHIP+ policy change there was an increase in total and female chlamydia cases however, the incidence rate ratio (IRR) was not statistically significant (IRR: 1.04, 95% CI: 0.91, 1.19), while total gonorrhea cases did increase significantly (IRR: 1.30, 95% CI: 1.11, 1.46). These findings suggest that expanded LARC access may be associated with an increase in disease incidence which provides valuable information for clinical and public health practice.