title: Structural factor analyses for medically unexplained somatic symptoms of somatization disorder in the Epidemiologic Catchment Area study.
abstract: BACKGROUND
  Assess the latent structure of the DSM-III somatization symptoms and the stability of symptom patterns over time.
  
  
  METHODS
  Cross-sectional and longitudinal covariation of symptoms of somatization disorder were investigated using structural equation models in a population-based data set from the Epidemiologic Catchment Area study.
  
  
  RESULTS
  Medically unexplained physical complaints were discovered to cluster into three separate factors, consistent with the DSM-IV definition of somatization disorder, but one dominant general factor was defined, consistent with the DSM-III conceptualization. Individual symptom prevalences and factor structures were different for men and women. The factor structures remained stable at 1 year follow-up. Variations in the threshold of number of somatization symptoms required for diagnosis affected prevalence, sex ratio and temporal stability of the diagnosis.
  
  
  CONCLUSIONS
  These population-based results support dimensional models of somatization. Implications for changing the threshold of the categorical diagnosis of somatization disorder and providing better care for these patients are given.
authors.affiliation: Department of Biostatistics, Johns Hopkins Hospital, Baltimore, MD 21287-5371, USA.
authors.forename: G
authors.initials: G
authors.lastname: Liu
authors.forename: M R
authors.initials: MR
authors.lastname: Clark
authors.forename: W W
authors.initials: WW
authors.lastname: Eaton
mesh_terms: D000328:Adult; D002908:Chronic Disease; D003291:Conversion Disorder / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005163:Factor Analysis, Statistical; D005260:Female; D006306:Health Surveys; D006801:Humans; D016018:Least-Squares Analysis; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D016017:Odds Ratio; D010146:Pain / Q000453:epidemiology / Q000523:psychology; D015995:Prevalence; D012016:Reference Values; D017678:Sex Distribution; D013001:Somatoform Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D014481:United States / Q000453:epidemiology