title: An empiric risk scoring tool for identifying high-risk heterosexual HIV-1-serodiscordant couples for targeted HIV-1 prevention.
abstract: OBJECTIVE
  Heterosexual HIV-1-serodiscordant couples are increasingly recognized as an important source of new HIV-1 infections in sub-Saharan Africa. A simple risk assessment tool could be useful for identifying couples at highest risk for HIV-1 transmission.
  
  
  METHODS
  Using data from 3 prospective studies of HIV-1-serodiscordant couples from 7 African countries and standard methods for development of clinical prediction rules, the authors derived and validated a risk scoring tool developed from multivariate modeling and composed of key predictors for HIV-1 risk that could be measured in standard research and clinical settings.
  
  
  RESULTS
  The final risk score included age of the HIV-1-uninfected partner, married and/or cohabiting partnership, number of children, unprotected sex, uncircumcised male HIV-1-uninfected partner, and plasma HIV-1 RNA in the HIV-1-infected partner. The maximum risk score was 12, scores ≥5 were associated with an annual HIV-1 incidence of >3%, and couples with a score ≥6 accounted for only 28% of the population but 67% of HIV-1 transmissions. The area under the curve for predictive ability of the score was 0.74 (95% confidence interval: 0.70 to 0.78). Internal and external validation showed similar predictive ability of the risk score, even when plasma viral load was excluded from the risk score.
  
  
  CONCLUSIONS
  A discrete combination of clinical and behavioral characteristics defines highest risk HIV-1-serodiscordant couples. Discriminating highest risk couples for HIV-1 prevention programs and clinical trials using a validated risk score could improve research efficiency and maximize the impact of prevention strategies for reducing HIV-1 transmission.
authors.affiliation: Department of Epidemiology, University of Washington, Seattle, WA 98104, USA. ekahle@u.washington.edu
authors.forename: Erin M
authors.initials: EM
authors.lastname: Kahle
authors.forename: James P
authors.initials: JP
authors.lastname: Hughes
authors.forename: Jairam R
authors.initials: JR
authors.lastname: Lingappa
authors.forename: Grace
authors.initials: G
authors.lastname: John-Stewart
authors.forename: Connie
authors.initials: C
authors.lastname: Celum
authors.forename: Edith
authors.initials: E
authors.lastname: Nakku-Joloba
authors.forename: Stella
authors.initials: S
authors.lastname: Njuguna
authors.forename: Nelly
authors.initials: N
authors.lastname: Mugo
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Bukusi
authors.forename: Rachel
authors.initials: R
authors.lastname: Manongi
authors.forename: Jared M
authors.initials: JM
authors.lastname: Baeten
mesh_terms: D000328:Adult; D015331:Cohort Studies; D036262:Empirical Research; D005260:Female; D015658:HIV Infections / Q000517:prevention & control*; D006679:HIV Seropositivity / Q000175:diagnosis*; D059147:HIV Serosorting; D015497:HIV-1; D020010:Heterosexuality; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012747:Sexual Partners