title: Low social class is linked to upper gastrointestinal symptoms in an Australian sample of urban adults.
abstract: OBJECTIVE
  The epidemiology of gastrointestinal (GI) symptoms has been described in population surveys, yet their distribution by socio-economic (social) class remains largely uninvestigated. The aim of this study was to evaluate the influence of social class on GI symptoms in an urban sample of Australian adults.
  
  
  METHODS
  The prevalence of 25 GI symptoms was determined by postal questionnaire. Five latent symptom groups were identified by a principal components analysis (PCA) (Esophageal, Dysmotility-like, Nausea/vomiting, Constipation and Diarrhea). These components were used to model the association between GI symptoms and adult social class. Social class was assigned according to a census-based measure of area disadvantage, and to highest level of completed education. Age- and sex-adjusted odds ratios - as identified by unconditional logistic regression - were used to describe the relationship between symptom groups and adult social class.
  
  
  RESULTS
  The effects of area disadvantage and education on Esophageal and Dysmotility-like symptoms were pronounced, with persistent trends for elevated symptom rates amongst the lower social classes (all p<0.01 on age- and sex-adjusted effects). When defined by area disadvantage, the odds ratios for Nausea/vomiting were significantly elevated among the lowest social class group (p=0.01), whereas the odds for Constipation were significantly elevated among the upper-middle social class when defined by education (p=0.001). Diarrhea was not associated with social class whether defined by area disadvantage or education.
  
  
  CONCLUSIONS
  Low social class is a risk factor for upper GI complaints.
authors.affiliation: School of Public Health, University of Sydney, Sydney, Australia.
authors.forename: Stuart C
authors.initials: SC
authors.lastname: Howell
authors.forename: Susan
authors.initials: S
authors.lastname: Quine
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Talley
mesh_terms: D000328:Adult; D000367:Age Factors; D001315:Australia / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D005767:Gastrointestinal Diseases / Q000453:epidemiology* / Q000209:etiology; D005769:Gastrointestinal Motility; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009325:Nausea / Q000453:epidemiology; D015995:Prevalence; D025341:Principal Component Analysis; D012307:Risk Factors; D012737:Sex Factors; D012923:Social Class; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D014505:Urban Population; D014839:Vomiting / Q000453:epidemiology