857. Discussion and Initiation of HIV Pre-exposure Prophylaxis Were Rare Following Diagnoses of Sexually Transmitted Infections among Veterans

Background Healthcare encounters for the diagnosis and treatment of sexually transmitted infections (STIs) are common and represent a window of opportunity to discuss and initiate HIV pre-exposure prophylaxis (PrEP). Little is known about how frequently PrEP is discussed and initiated in association with encounters for STIs. Methods We conducted a retrospective cohort and nested case control study in the national Veterans Administration (VA) healthcare system to determine the frequency of PrEP discussion and initiation in association with clinical encounters for bacterial STIs (i.e. early syphilis, gonorrhea, and chlamydia). We used administrative data to identify patients with a first STI based on ICD 9 / 10 codes from January 2013–December 2018 , excluding patients with prior HIV diagnosis or PrEP use, or STI diagnosed in context of a visit to initiate PrEP (Figure 1). We used pharmacy data to determine the frequency of PrEP initiation within 90 days of the encounter for STI in this cohort. In the case control study, we matched 90 PrEP starters to 180 non-starters by day of STI diagnosis and reviewed chart notes from the STI diagnosis encounter to determine frequency of documentation of sexual history taking and PrEP discussions among subsequent PrEP initiators and non-initiators. Results We identified 23,312 patients with a first STI, of whom 90 (0.4%) started PrEP within 90 days. Adjusting for age, PrEP initiation was associated with urban residence (OR=5.0, 95Cl 1.8–13.4), White compared to Black race (OR=1.7, 95 Cl 1.1–2.8), and syphilis diagnosis (OR = 7.4, 95 Cl 4.7–11.6, table 1). Chart review revealed that discussion of PrEP was rare among people with STIs who did not subsequently start PrEP (1.1%, 95 CI 0.1–4.0, table 2). PrEP initiation was associated with documentation of any sexual history (80.0% of initiators vs. 51.0% of non-initiators, p < 0.01) and discussion of PrEP (52.2% vs. 1.1%, p < 0.01) during the initial STI diagnosis encounter. Figure 1. Study flow chart Table 1. Characteristics of patients with a first healthcare encounter with an STI diagnosis, by PrEP initiation within 90 days of encounter. N= 23,312 Table 2. Chart review findings from case control study. Ninety people who initiated PrEP (i.e., “cases”) were randomly matched to 180 who did not initiate PrEP (i.e., “controls”) by date of STI. Conclusion Discussion and initiation of PrEP were rare in association with healthcare encounters for STIs. Not all individuals with STIs will benefit from starting PrEP, but interventions are needed to improve low rates of sexual history-taking and discussion of PrEP during healthcare encounters for STIs. Disclosures Bruce Alexander, PharmD, Bruce Alexander Consulting (Independent Contractor)