title: Disassortative Age-Mixing Does Not Explain Differences in HIV Prevalence between Young White and Black MSM: Findings from Four Studies.
abstract: OBJECTIVE
  Age disassortativity is one hypothesis for HIV disparities between Black and White MSM. We examined differences in age mixing by race and the effect of partner age difference on the association between race and HIV status.
  
  
  METHODS
  We used data from four studies of MSM. Participants reported information about recent sexual partners, including age, race, and sexual behavior. Two studies were online with a US sample and two focused on MSM in Atlanta.
  
  
  METHODS
  We computed concordance correlation coefficients (CCCs) by race across strata of partner type, participant HIV status, condom use, and number of partners. We used Wilcoxon rank-sum tests to compare Black and White MSM on partner age differences across five age groups. Finally, we used logistic regression models using race, age, and partner age difference to determine the odds ratio of HIV-positive serostatus.
  
  
  RESULTS
  Of 48 CCC comparisons, Black MSM were more age-disassortative than White MSM in only two. Furthermore, of 20 comparisons of median partner age, Black and White MSM differed in two age groups. One indicated larger age gaps among the Black MSM (18-19). Prevalent HIV infection was associated with race and age. Including partner age difference in the model resulted in a 2% change in the relative odds of infection among Black MSM.
  
  
  CONCLUSIONS
  Partner age disassortativity and partner age differences do not differ by race. Partner age difference offers little predictive value in understanding prevalent HIV infection among Black and White MSM, including diagnosis of HIV-positive status among self-reported HIV-negative individuals.
authors.affiliation: Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America.
authors.forename: Jeremy Alexander
authors.initials: JA
authors.lastname: Grey
authors.affiliation: Institute of Public Health, Georgia State University, Atlanta, Georgia, United States of America.
authors.forename: Richard B
authors.initials: RB
authors.lastname: Rothenberg
authors.affiliation: Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America.
authors.forename: Patrick Sean
authors.initials: PS
authors.lastname: Sullivan
authors.affiliation: Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America.
authors.forename: Eli Samuel
authors.initials: ES
authors.lastname: Rosenberg
mesh_terms: D000293:Adolescent; D000328:Adult; D044383:Black People; D003430:Cross-Sectional Studies; D005260:Female; D005845:Georgia / Q000453:epidemiology; D015658:HIV Infections / Q000453:epidemiology* / Q000821:virology; D018451:Homosexuality, Male; D006801:Humans; D020407:Internet; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011159:Population Surveillance; D015995:Prevalence; D012725:Sexual Behavior; D012747:Sexual Partners; D011795:Surveys and Questionnaires; D044465:White People; D055815:Young Adult; D001741:Black or African American