title: Performance of an electronic health record-based phenotype algorithm to identify community associated methicillin-resistant Staphylococcus aureus cases and controls for genetic association studies.
abstract: Community associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is one of the most common causes of skin and soft tissue infections in the United States, and a variety of genetic host factors are suspected to be risk factors for recurrent infection. Based on the CDC definition, we have developed and validated an electronic health record (EHR) based CA-MRSA phenotype algorithm utilizing both structured and unstructured data.
  
  
  
  The algorithm was validated at three eMERGE consortium sites, and positive predictive value, negative predictive value and sensitivity, were calculated. The algorithm was then run and data collected across seven total sites. The resulting data was used in GWAS analysis.
  
  
  
  Across seven sites, the CA-MRSA phenotype algorithm identified a total of 349 cases and 7761 controls among the genotyped European and African American biobank populations. PPV ranged from 68 to 100% for cases and 96 to 100% for controls; sensitivity ranged from 94 to 100% for cases and 75 to 100% for controls. Frequency of cases in the populations varied widely by site. There were no plausible GWAS-significant (p < 5 E -8) findings.
  
  
  
  Differences in EHR data representation and screening patterns across sites may have affected identification of cases and controls and accounted for varying frequencies across sites. Future work identifying these patterns is necessary.
authors.affiliation: Feinberg School of Medicine, Northwestern University, Chicago, IL, USA. kathryn.jackson1@northwestern.edu.
authors.forename: Kathryn L
authors.initials: KL
authors.lastname: Jackson
authors.affiliation: Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Mbagwu
authors.affiliation: Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Pacheco
authors.affiliation: Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: Abigail S
authors.initials: AS
authors.lastname: Baldridge
authors.affiliation: Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.|Emory University School of Medicine, Atlanta, GA, USA.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Viox
authors.affiliation: Biomedical Informatics Research Center, Marshfield Clinic Research Foundation, Marshfield, WI, USA.
authors.forename: James G
authors.initials: JG
authors.lastname: Linneman
authors.affiliation: Marshfield Clinic Research Foundation, Marshfield, WI, USA.
authors.forename: Sanjay K
authors.initials: SK
authors.lastname: Shukla
authors.affiliation: Biomedical Informatics Research Center, Marshfield Clinic Research Foundation, Marshfield, WI, USA.
authors.forename: Peggy L
authors.initials: PL
authors.lastname: Peissig
authors.affiliation: Geisinger Health System, Danville, PA, USA.
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Borthwick
authors.affiliation: Group Health Research Institute, Group Health Cooperative, Seattle, WA, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Carrell
authors.affiliation: Mayo Clinic, Rochester, MN, USA.
authors.forename: Suzette J
authors.initials: SJ
authors.lastname: Bielinski
authors.affiliation: Department of Biomedical Informatics, Vanderbilt University, Nashville, TN, USA.
authors.forename: Jacqueline C
authors.initials: JC
authors.lastname: Kirby
authors.affiliation: Department of Biomedical Informatics, Vanderbilt University, Nashville, TN, USA.
authors.forename: Joshua C
authors.initials: JC
authors.lastname: Denny
authors.affiliation: The Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Frank D
authors.initials: FD
authors.lastname: Mentch
authors.affiliation: The Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Lyam M
authors.initials: LM
authors.lastname: Vazquez
authors.affiliation: Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Rasmussen-Torvik
authors.affiliation: Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: Abel N
authors.initials: AN
authors.lastname: Kho
mesh_terms: D000328:Adult; D000465:Algorithms; D016022:Case-Control Studies; D017714:Community-Acquired Infections / Q000175:diagnosis / Q000235:genetics; D057286:Electronic Health Records; D005260:Female; D020022:Genetic Predisposition to Disease; D055106:Genome-Wide Association Study / Q000379:methods*; D006801:Humans; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus; D010641:Phenotype; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000175:diagnosis* / Q000235:genetics; D014481:United States
keywords: Electronic Health Record; GWAS; Phenotyping; ca-MRSA Phenotype; ca_MRSA