title: Comparing administrative and survey data for ascertaining cases of irritable bowel syndrome: a population-based investigation.
abstract: BACKGROUND
  Administrative and survey data are two key data sources for population-based research about chronic disease. The objectives of this methodological paper are to: (1) estimate agreement between the two data sources for irritable bowel syndrome (IBS) and compare the results to those for inflammatory bowel disease (IBD); (2) compare the frequency of IBS-related diagnoses in administrative data for survey respondents with and without self-reported IBS, and (3) estimate IBS prevalence from both sources.
  
  
  METHODS
  This retrospective cohort study used linked administrative and health survey data for 5,134 adults from the province of Manitoba, Canada. Diagnoses in hospital and physician administrative data were investigated for respondents with self-reported IBS, IBD, and no bowel disorder. Agreement between survey and administrative data was estimated using the kappa statistic. The chi2 statistic tested the association between the frequency of IBS-related diagnoses and self-reported IBS. Crude, sex-specific, and age-specific IBS prevalence estimates were calculated from both sources.
  
  
  RESULTS
  Overall, 3.0% of the cohort had self-reported IBS, 0.8% had self-reported IBD, and 95.3% reported no bowel disorder. Agreement was poor to fair for IBS and substantially higher for IBD. The most frequent IBS-related diagnoses among the cohort were anxiety disorders (34.4%), symptoms of the abdomen and pelvis (26.9%), and diverticulitis of the intestine (10.6%). Crude IBS prevalence estimates from both sources were lower than those reported previously.
  
  
  CONCLUSIONS
  Poor agreement between administrative and survey data for IBS may account for differences in the results of health services and outcomes research using these sources. Further research is needed to identify the optimal method(s) to ascertain IBS cases in both data sources.
authors.affiliation: School of Public Health, University of Saskatchewan, Saskatoon, Canada. lisa.lix@usask.ca
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Lix
authors.forename: Marina S
authors.initials: MS
authors.lastname: Yogendran
authors.forename: Souradet Y
authors.initials: SY
authors.lastname: Shaw
authors.forename: Laura E
authors.initials: LE
authors.lastname: Targownick
authors.forename: Jennifer
authors.initials: J
authors.lastname: Jones
authors.forename: Osama
authors.initials: O
authors.lastname: Bataineh
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003627:Data Interpretation, Statistical; D005260:Female; D006306:Health Surveys; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000453:epidemiology*; D008297:Male; D008350:Manitoba / Q000453:epidemiology; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D012959:Socioeconomic Factors; D014505:Urban Population