title: Sexual risk trajectories among MSM in the United States: implications for pre-exposure prophylaxis delivery.
abstract: BACKGROUND
  Despite evidence supporting pre-exposure prophylaxis (PrEP) efficacy, there are concerns regarding the feasibility of widespread PrEP implementation among men who have sex with men (MSM). To inform the development of targeted PrEP delivery guidelines, sexual risk trajectories among HIV-negative MSM were characterized.
  
  
  METHODS
  At semiannual visits from 2003 to 2011, HIV-negative MSM (N = 419) participating in the Multicenter AIDS Cohort Study provided data on sexual risk behaviors (SRBs) since their last visit. Based on their reported behaviors, participants were assigned a SRB score at each visit as follows: 0 = no insertive or receptive anal intercourse, 1 = no unprotected insertive or receptive anal intercourse, 2 = only unprotected insertive anal intercourse, 3 = unprotected receptive anal intercourse with 1 HIV-negative partner, 4 = condom serosorting, 5 = condom seropositioning, and 6 = no seroadaptive behaviors. Group-based trajectory modeling was used to examine SRB scores (<4 vs. ≥4) and identify groups with distinct sexual risk trajectories.
  
  
  RESULTS
  Three sexual risk trajectory groups were identified: low-risk (n = 264; 63.0%), moderate-risk (n = 96; 22.9%; mean duration of consecutive high-risk intervals ∼1 year), and high-risk (n = 59; 14.1%; mean duration of consecutive high-risk intervals ∼2 years). Compared to low-risk group membership, high-risk group membership was associated with younger age (in years) [adjusted odds ratio (AOR) = 0.92, 95% confidence interval (CI): 0.88 to 0.96], being White (AOR = 3.67, 95% CI: 1.48 to 9.11), earning an income ≥$20,000 (AOR = 4.98, 95% CI: 2.13 to 11.64), distress/depression symptoms (Center for Epidemiologic Studies Depression Scale ≥ 16) (AOR = 2.36, 95% CI: 1.14 to 4.92), and substance use (AOR = 2.00, 95% CI: 1.01 to 3.97).
  
  
  CONCLUSIONS
  Screening for the sociodemographic and behavioral factors described above may facilitate targeted PrEP delivery during high-risk periods among MSM.
authors.affiliation: Departments of *Epidemiology; †Biostatistics, Fielding School of Public Health, University of California, Los Angeles, CA; Departments of ‡Family Medicine; §Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, CA; ‖Center for Clinical AIDS Research & Education, David Geffen School of Medicine, University of California, Los Angeles, CA; ¶David Ostrow & Associates, LLC Chicago, IL; #The Chicago MACS, Northwestern University, Evanston, IL; **Department of Behavioral and Community Health Sciences, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA; and ††Department of Medicine, Georgetown University Medical Center, Washington, DC.
authors.forename: Heather A
authors.initials: HA
authors.lastname: Pines
authors.forename: Pamina M
authors.initials: PM
authors.lastname: Gorbach
authors.forename: Robert E
authors.initials: RE
authors.lastname: Weiss
authors.forename: Steve
authors.initials: S
authors.lastname: Shoptaw
authors.forename: Raphael J
authors.initials: RJ
authors.lastname: Landovitz
authors.forename: Marjan
authors.initials: M
authors.lastname: Javanbakht
authors.forename: David G
authors.initials: DG
authors.lastname: Ostrow
authors.forename: Ron D
authors.initials: RD
authors.lastname: Stall
authors.forename: Michael
authors.initials: M
authors.lastname: Plankey
mesh_terms: D000328:Adult; D018890:Chemoprevention / Q000379:methods*; D015658:HIV Infections / Q000517:prevention & control*; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012309:Risk-Taking; D013997:Time Factors; D014481:United States