Publications
Department of Medicine faculty members published more than 3,000 peer-reviewed articles in 2022.
2019
2019
Increasing rates of sexually transmitted infections (STIs) in the United States among men who have sex with men (MSM) have raised concerns that pre-exposure prophylaxis (PrEP) has been associated with higher engagement in condomless anal intercourse (CAI). While partnership characteristics have previously been found to influence condom use, the extent to which PrEP use may modify their effect on CAI remains unknown. A secondary analysis of 535 sexual partnerships from a cross-sectional study in San Francisco was conducted to evaluate interactions between PrEP use and partnership characteristics on CAI. Bivariate and multivariate generalized estimating equation (GEE) logistic regression models were used to estimate relative measures of association, adjusted for confounding by seroconcordance and partnership type, as well as account for repeated partnerships per respondent. Partnerships where both partners used biomedical prevention had significantly greater odds of CAI [odds ratio (OR) = 5.19, 95% confidence interval (CI): 2.27-11.9] compared to those where only one partner used biomedical prevention, while those where neither partner used biomedical prevention had significantly lower odds of CAI (OR = 0.61, 95% CI: 0.40-0.93). There was no significant association between meeting place (online vs. offline) and sexual risk taking (OR = 1.03, p = 0.894). Having one partner disclose their HIV status (compared to neither partner having disclosed) was associated with significantly higher odds of CAI among partnerships of PrEP-using MSM [adjusted OR (aOR) = 5.28, 95% CI: 1.91-14.61], while the association was not significant among the partnerships of non-PrEP-using MSM (aOR = 1.29, 95% CI: 0.75-2.21). Differences in condom use among MSM using PrEP may not be well explained by differences in the effect of partnership characteristics. MSM using PrEP appear to commonly practice biomedical matching and high engagement in CAI with other biomedical prevention users, which could indicate relatively concentrated sexual networks and partly explain their disproportionate risk for STIs. Future studies should further investigate biomedical matching to develop interventions that further promote the sexual health of those using PrEP.
View on PubMed2019
2019
Importance
Randomized clinical trials have demonstrated that patients with asymptomatic carotid stenosis are eligible for carotid endarterectomy (CEA) if the 30-day surgical complication rate is less than 3% and the patient's life expectancy is at least 5 years.
Objective
To develop a risk prediction tool to improve patient selection for CEA among patients with asymptomatic carotid stenosis.
Design, Setting, and Participants
In this cohort study, veterans 65 years and older who received both carotid imaging and CEA in the Veterans Administration between January 1, 2005, and December 31, 2009 (n = 2325) were followed up for 5 years. Data were analyzed from January 2005 to December 2015. A risk prediction tool (the Carotid Mortality Index [CMI]) based on 23 candidate variables identified in the literature was developed using Veterans Administration and Medicare data. A simpler model based on the number of 4 key comorbidities that were prevalent and strongly associated with 5-year mortality was also developed (any cancer in the past 5 years, chronic obstructive pulmonary disease, congestive heart failure, and chronic kidney disease [the 4C model]). Model performance was assessed using measures of discrimination (eg, area under the curve [AUC]) and calibration. Internal validation was performed by correcting for optimism using 500 bootstrapped samples.
Main Outcome and Measure
Five-year mortality.
Results
Among 2325 veterans, the mean (SD) age was 73.74 (5.92) years. The cohort was predominantly male (98.8%) and of white race/ethnicity (94.4%). Overall, 29.5% (n = 687) of patients died within 5 years of CEA. On the basis of a backward selection algorithm, 9 patient characteristics were selected (age, chronic kidney disease, diabetes, chronic obstructive pulmonary disease, any cancer diagnosis in the past 5 years, congestive heart failure, atrial fibrillation, remote stroke or transient ischemic attack, and body mass index) for the final logistic model, which yielded an optimism-corrected AUC of 0.687 for the CMI. The 4C model had slightly worse discrimination (AUC, 0.657) compared with the CMI model; however, the calibration curve was similar to the full model in most of the range of predicted probabilities.
Conclusions and Relevance
According to results of this study, use of the CMI or the simpler 4C model may improve patient selection for CEA among patients with asymptomatic carotid stenosis.
View on PubMed2019
Current strategies to prevent sexually transmitted infections (STIs) are not controlling the epidemic. The efficacy of doxycycline STI postexposure prophylaxis shows promise in pilot studies, but wider acceptability is unknown. A majority (84%) of diverse individuals using a gay social networking application were interested in doxycycline STI postexposure prophylaxis. Doxycycline STI postexposure prophylaxis should be examined in larger trials.
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