Background
In 2024, San Francisco Department of Public Health released updated recommendations for prescribing doxycycline post-exposure prophylaxis (doxy-PEP). These matched CDC guidance and additionally encouraged shared decision-making between providers and patients with at least 2 sex partners in the last year who were assigned male sex at birth. San Francisco AIDS Foundation’s Magnet Clinic, a large, community-based clinic in San Francisco’s Castro neighborhood, provides doxy-PEP in line with these recommendations. We used Magnet Clinic patient data to define and produce population estimates for a doxy-PEP continuum among patients with indication for doxy-PEP overall and stratified by select demographics. At each stage of the continuum, we assessed whether characteristics were associated with drop-off.
Methods
Among patients seen from December 2022-December 2024, we restricted to those with (1) a doxy-PEP indication. We then estimated the proportion who (2) received a doxy-PEP prescription; (3) initiated (i.e. self-reported ever taking) doxy-PEP; and (4) adhered to doxy-PEP (i.e. self-reported consistent use within 72 hours after sexual exposures since their last clinic visit). We stratified these analyses by several sociodemographic and health characteristics. We conducted one-tailed tests of equal proportions in each stratified analysis, where the referent was the group most likely to reach a given stage in the continuum conditional on reaching the prior stage.
Results
In the study period, 7,436 patients with indication for doxy-PEP were seen at the Magnet Clinic. Among them, 4,369 (60%) were prescribed doxy-PEP. Among those prescribed, 2,651 (61%) reported using it at least once. Among those who used doxy-PEP, 1,627 (61%) reported high adherence at their most recent clinic visit (Figure). Among patients with indications, transgender women were more likely to be prescribed doxy-PEP compared with other gender identities. At each stage of the continuum, patients living with HIV had higher drop-off rates compared to HIV-negative patients.
Conclusions
Although doxy-PEP is a safe, low-cost biomedical intervention for bacterial sexually transmitted infections, only 36% of Magnet Clinic patients with indication ever used it, and less than 25% were adherent. To maximize the impact of doxy-PEP, clinicians should encourage increased uptake and adherence among those with indication.