title: Socioeconomic Factors Explain Racial Disparities in Invasive Community-Associated Methicillin-Resistant Staphylococcus aureus Disease Rates.
abstract: Invasive community-associated methicillin-resistant Staphylococcus aureus (MRSA) incidence in the United States is higher among black persons than white persons. We explored the extent to which socioeconomic factors might explain this racial disparity.
  
  
  
  A retrospective cohort was based on the Centers for Disease Control and Prevention's Emerging Infections Program surveillance data for invasive community-associated MRSA cases (isolated from a normally sterile site of an outpatient or on hospital admission day ≤3 in a patient without specified major healthcare exposures) from 2009 to 2011 in 33 counties of 9 states. We used generalized estimating equations to determine census tract-level factors associated with differences in MRSA incidence and inverse odds ratio-weighted mediation analysis to determine the proportion of racial disparity mediated by socioeconomic factors.
  
  
  
  Annual invasive community-associated MRSA incidence was 4.59 per 100000 among whites and 7.60 per 100000 among blacks (rate ratio [RR], 1.66; 95% confidence interval [CI], 1.52-1.80). In the mediation analysis, after accounting for census tract-level measures of federally designated medically underserved areas, education, income, housing value, and rural status, 91% of the original racial disparity was explained; no significant association of black race with community-associated MRSA remained (RR, 1.05; 95% CI, .92-1.20).
  
  
  
  The racial disparity in invasive community-associated MRSA rates was largely explained by socioeconomic factors. The specific factors that underlie the association between census tract-level socioeconomic measures and MRSA incidence, which may include modifiable social (eg, poverty, crowding) and biological factors (not explored in this analysis), should be elucidated to define strategies for reducing racial disparities in community-associated MRSA rates.
authors.affiliation: Division of Healthcare Quality Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Isaac
authors.initials: I
authors.lastname: See
authors.affiliation: Division of Epidemiology, School of Public Health, University of California, Berkeley, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Wesson
authors.affiliation: Division of Healthcare Quality Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Nicole
authors.initials: N
authors.lastname: Gualandi
authors.affiliation: University of Rochester Medical Center, Rochester, New York, USA.
authors.forename: Ghinwa
authors.initials: G
authors.lastname: Dumyati
authors.affiliation: Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
authors.forename: Lee H
authors.initials: LH
authors.lastname: Harrison
authors.affiliation: Minnesota Department of Health, St Paul, Minnesota, USA.
authors.forename: Lindsey
authors.initials: L
authors.lastname: Lesher
authors.affiliation: California Emerging Infections Program, Oakland, USA.
authors.forename: Joelle
authors.initials: J
authors.lastname: Nadle
authors.affiliation: Connecticut Department of Public Health, Hartford, USA.
authors.forename: Susan
authors.initials: S
authors.lastname: Petit
authors.affiliation: Colorado Department of Public Health and Environment, Denver, USA.
authors.forename: Claire
authors.initials: C
authors.lastname: Reisenauer
authors.affiliation: Vanderbilt University Medical Center, Nashville, Tennessee, USA.
authors.forename: William
authors.initials: W
authors.lastname: Schaffner
authors.affiliation: Georgia Emerging Infections Program, Atlanta, USA.
authors.forename: Amy
authors.initials: A
authors.lastname: Tunali
authors.affiliation: Division of Healthcare Quality Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Mu
authors.affiliation: Division of Epidemiology, School of Public Health, University of California, Berkeley, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Ahern
mesh_terms: D000328:Adult; D000368:Aged; D017714:Community-Acquired Infections / Q000453:epidemiology* / Q000382:microbiology; D015897:Comorbidity; D005006:Ethnicity; D005260:Female; D054625:Healthcare Disparities; D006801:Humans; D015994:Incidence; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus; D008875:Middle Aged; D012959:Socioeconomic Factors; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D014481:United States / Q000453:epidemiology
keywords: antibiotic resistance; methicillin-resistant Staphylococcus aureus; racial disparities; social determinants of health