title: Factor analysis of the clinical characteristics of primary Sjogren syndrome.
abstract: OBJECTIVE
  The purpose of this study was to use factor analysis to analyze 90 clinical characteristics of a cohort of 231 patients with primary Sjogren syndrome (pSS).
  
  
  METHODS
  The records of all patients seen at the University Health Network Sjogren Syndrome Clinic from October 1992 to July 2006 were reviewed and documented. Those diagnosed as pSS by the American European Consensus Criteria of 2002 were included. The 90 clinical variables, including health history, blood analysis, symptoms of dry eye and dry mouth, salivary flow and biopsy, tear flow and staining, were analyzed by factor analysis.
  
  
  RESULTS
  Two hundred thirty-one patients with pSS charts were reviewed, and 90 variables were recorded. Factor analysis resulted in three factors: factor 1: ocular surface staining, factor 2: antimicrosomal antibodies and antithyroid antibodies, and factor 3: serum anti-Ro and anti-La.
  
  
  CONCLUSIONS
  Ocular surface staining accounted for the greatest variance in this population of patients with pSS.
authors.affiliation: School of Optometry, University of Waterloo, Waterloo, Ontario, Canada. barbaracafferyeyes@yahoo.ca
authors.forename: Barbara
authors.initials: B
authors.lastname: Caffery
authors.forename: Trefford
authors.initials: T
authors.lastname: Simpson
authors.forename: Sunny
authors.initials: S
authors.lastname: Wang
authors.forename: Denis
authors.initials: D
authors.lastname: Bailey
authors.forename: John
authors.initials: J
authors.lastname: McComb
authors.forename: John
authors.initials: J
authors.lastname: Rutka
authors.forename: Allan
authors.initials: A
authors.lastname: Slomovic
authors.forename: Arthur
authors.initials: A
authors.lastname: Bookman
mesh_terms: D001706:Biopsy; D005123:Eye / Q000473:pathology*; D005163:Factor Analysis, Statistical; D006801:Humans; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012859:Sjogren's Syndrome / Q000175:diagnosis*; D013194:Staining and Labeling / Q000379:methods*; D013666:Tears