Characterization of HIV Preexposure Prophylaxis Use Behaviors and HIV Incidence Among US Adults in an Integrated Health Care System.

Importance: Long-term follow-up is needed to evaluate gaps in HIV preexposure prophylaxis (PrEP) care delivery and to identify individuals at risk for falling out of care. Objective: To characterize the PrEP continuum of care, including prescription, initiation, discontinuation, and reinitiation, and evaluate incident HIV infections. Design, Setting, and Participants: This retrospective cohort study used data from the electronic health records (EHR) at Kaiser Permanente Northern California to identify individuals aged 18 years and older who received PrEP care between July 2012 and March 2019. Individuals were followed up from date of linkage (defined as a PrEP referral or PrEP-coded encounter) until March 2019, HIV diagnosis, discontinuation of health plan membership, or death. Data were analyzed from December 2019 to January 2021. Exposures: Sociodemographic factors included age, sex, race and ethnicity, and neighborhood deprivation index, and clinical characteristics were extracted from the EHR. Main Outcomes and Measures: The primary outcomes were attrition at each step of the PrEP continuum of care and incident HIV infections. Results: Among 13 906 individuals linked to PrEP care, the median (interquartile range [IQR]) age was 33 (27-43) years, 6771 individuals (48.7%) were White, and 13 227 (95.1%) were men. Total follow-up was 26 210 person-years (median [IQR], 1.6 [0.7-2.8] years). Of individuals linked to PrEP care, 88.1% (95% CI, 86.1%-89.9%) were prescribed PrEP and of these, 98.2% (95% CI, 97.2%-98.8%) initiated PrEP. After PrEP initiation, 52.2% (95% CI, 48.9%-55.7%) discontinued PrEP at least once during the study period, and 60.2% (95% CI, 52.2%-68.3%) of these individuals subsequently reinitiated. Compared with individuals aged 18 to 25 years, older individuals were more likely to receive a PrEP prescription (eg, age >45 years: hazard ratio [HR], 1.21 [95% CI, 1.14-1.29]) and initiate PrEP (eg, age >45 years: HR, 1.09 [95% CI, 1.02-1.16]) and less likely to discontinue (eg, age >45 years: HR, 0.46 [95% CI, 0.42-0.52]). Compared with White patients, African American and Latinx individuals were less likely to receive a PrEP prescription (African American: HR, 0.74 [95% CI, 0.69-0.81]; Latinx: HR, 0.88 [95% CI, 0.84-0.93]) and initiate PrEP (African American: HR, 0.87 [95% CI, 0.80-0.95]; Latinx: HR, 0.90 [95% CI, 0.86-0.95]) and more likely to discontinue (African American: HR, 1.36 [95% CI, 1.17-1.57]; Latinx: 1.33 [95% CI, 1.22-1.46]). Similarly, women, individuals with lower neighborhood-level socioeconomic status (SES), and persons with a substance use disorder (SUD) were less likely to be prescribed (women: HR, 0.56 [95% CI, 0.50-0.62]; lowest SES: HR, 0.72 [95% CI, 0.68-0.76]; SUD: HR, 0.88 [95% CI, 0.82-0.94]) and initiate PrEP (women: HR, 0.71 [95% CI, 0.64-0.80]; lower SES: HR, 0.93 [95% CI, 0.87-.0.99]; SUD: HR, 0.88 [95% CI, 0.81-0.95]) and more likely to discontinue (women: HR, 1.99 [95% CI, 1.67-2.38]); lower SES: HR, 1.40 [95% CI, 1.26-1.57]; SUD: HR, 1.23 [95% CI, 1.09-1.39]). HIV incidence was highest among individuals who discontinued PrEP and did not reinitiate PrEP (1.28 [95% CI, 0.93-1.76] infections per 100 person-years). Conclusions and Relevance: These findings suggest that gaps in the PrEP care continuum were concentrated in populations disproportionately impacted by HIV, including African American individuals, Latinx individuals, young adults (aged 18-25 years), and individuals with SUD. Comprehensive strategies to improve PrEP continuum outcomes are needed to maximize PrEP impact and equity.

Use of electronic health record data and machine learning to identify candidates for HIV pre-exposure prophylaxis: a modelling study.

BACKGROUND: The limitations of existing HIV risk prediction tools are a barrier to implementation of pre-exposure prophylaxis (PrEP). We developed and validated an HIV prediction model to identify potential PrEP candidates in a large health-care system. METHODS: Our study population was HIV-uninfected adult members of Kaiser Permanente Northern California, a large integrated health-care system, who were not yet using PrEP and had at least 2 years of previous health plan enrolment with at least one outpatient visit from Jan 1, 2007, to Dec 31, 2017. Using 81 electronic health record (EHR) variables, we applied least absolute shrinkage and selection operator (LASSO) regression to predict incident HIV diagnosis within 3 years on a subset of patients who entered the cohort in 2007-14 (development dataset), assessing ten-fold cross-validated area under the receiver operating characteristic curve (AUC) and 95% CIs. We compared the full model to simpler models including only men who have sex with men (MSM) status and sexually transmitted infection (STI) positivity, testing, and treatment. Models were validated prospectively with data from an independent set of patients who entered the cohort in 2015-17. We computed predicted probabilities of incident HIV diagnosis within 3 years (risk scores), categorised as low risk (<0·05%), moderate risk (0·05% to <0·20%), high risk (0·20% to <1·0%), and very high risk (≥1·0%), for all patients in the validation dataset. FINDINGS: Of 3 750 664 patients in 2007-17 (3 143 963 in the development dataset and 606 701 in the validation dataset), there were 784 incident HIV cases within 3 years of baseline. The LASSO procedure retained 44 predictors in the full model, with an AUC of 0·86 (95% CI 0·85-0·87) for incident HIV cases in 2007-14. Model performance remained high in the validation dataset (AUC 0·84, 0·80-0·89). The full model outperformed simpler models including only MSM status and STI positivity. For the full model, flagging 13 463 (2·2%) patients with high or very high HIV risk scores in the validation dataset identified 32 (38·6%) of the 83 incident HIV cases, including 32 (46·4%) of 69 male cases and none of the 14 female cases. The full model had equivalent sensitivity by race whereas simpler models identified fewer black than white HIV cases. INTERPRETATION: Prediction models using EHR data can identify patients at high risk of HIV acquisition who could benefit from PrEP. Future studies should optimise EHR-based HIV risk prediction tools and evaluate their effect on prescription of PrEP. FUNDING: Kaiser Permanente Community Benefit Research Program and the US National Institutes of Health.

Risk Perception, Sexual Behaviors, and PrEP Adherence Among Substance-Using Men Who Have Sex with Men: a Qualitative Study.

The antiretroviral drug combination emtricitabine and tenofovir disoproxil fumarate (TDF/FTC) taken as pre-exposure prophylaxis (PrEP) is effective in preventing HIV infection, yet it also requires adherence and potentially decreases condom use. This study sought to examine these issues among a key population at risk of HIV infection, substance-using men who have sex with men (MSM). We conducted semi-structured interviews with an ethnically diverse sample of 30 young (aged 20-35) MSM prescribed PrEP within a large integrated healthcare system in San Francisco, who had reported recent drug use or hazardous drinking and one or more missed doses of PrEP. We explored participants' risk perception and sexual risk behavior, drug and alcohol use, and PrEP adherence in the context of substance use. Interviews were transcribed and coded using a directed content analysis approach to identify key categories and commonalities, and differences across participants. Salient subcategories included positive psychological effects of being on PrEP (e.g., decreased anxiety, feelings of empowerment), social effects (e.g., reduced HIV stigma), and reduction in overall perceptions of HIV risk. While overall reported use of condoms went down and many reported a brief period of increased condomless sex following PrEP initiation, others continued condom use with most of their sexual partners. Contextual factors influencing their decision to engage in condomless sex included how well they knew the partner and whether the partner was on PrEP or HIV antiretroviral treatment. Factors associated with poor adherence included disruptions in daily routine and use of alcohol and methamphetamine. PrEP-prescribing clinicians should support their patients in making informed decisions about condom use and identifying strategies to maximize adherence in the context of substance use.

Preexposure Prophylaxis for HIV Prevention in a Large Integrated Health Care System: Adherence, Renal Safety, and Discontinuation.

BACKGROUND: Placebo-controlled and open-label studies have demonstrated the safety and efficacy of daily oral preexposure prophylaxis (PrEP) in preventing HIV infection, but data are limited on real-world PrEP use. METHODS: We conducted a cohort study from July 2012 through June 2015 of Kaiser Permanente Northern California members initiating PrEP. We assessed pharmacy refill adherence and discontinuation, decreases in estimated glomerular filtration rate (eGFR), and sexually transmitted infection (STI)/HIV incidence. RESULTS: Overall, 972 individuals initiated PrEP, accumulating 850 person-years of PrEP use. Mean adherence was 92% overall. Black race/ethnicity [adjusted risk ratio (aRR) 3.0; 95% confidence interval: 1.7 to 5.1, P < 0.001], higher copayments (aRR 2.0; 1.2 to 3.3, P = 0.005), and smoking (aRR 1.6; 1.1 to 2.3, P = 0.025) were associated with <80% adherence. PrEP was discontinued by 219 (22.5%); female sex (aRR 2.6; 1.5 to 4.6, P < 0.001) and drug/alcohol abuse (aRR 1.8; 1.3 to 2.6, P = 0.002) were associated with discontinuation. Among 909 with follow-up creatinine testing, 141 (15.5%) had an eGFR <70 mL·min·1.73 m and 5 (0.6%) stopped PrEP because of low eGFR. Quarterly STI positivity was high and increased over time for rectal chlamydia (P < 0.001) and urethral gonorrhea (P = 0.012). No HIV seroconversions occurred during PrEP use; however, 2 occurred in individuals who discontinued PrEP after losing insurance coverage. CONCLUSIONS: PrEP adherence was high in clinical practice, consistent with the lack of HIV seroconversions during PrEP use. Discontinuation because of renal toxicity was rare. STI screening every 6 months, as recommended by current guidelines, may be inadequate. Strategies are needed to increase PrEP access during gaps in insurance coverage.