title: Acute colonic diverticulitis: diagnostic evidence, demographic and clinical features in three practice settings.
abstract: OBJECTIVE
  Diverticulitis is often diagnosed in outpatients, yet little evidence exists on diagnostic evidence and demographic/clinical features in various practice settings. We assessed variation in clinical characteristics and diagnostic evidence in inpatients, outpatients, and emergency department cases and effects of demographic and clinical variables on presentation features.
  
  
  METHODS
  In a retrospective cohort study of 1749 patients in an integrated health care system, we compared presenting features and computed tomography findings by practice setting and assessed independent effects of demographic and clinical factors on presenting features.
  
  
  RESULTS
  Inpatients were older and more often underweight/normal weight and lacked a diverticulitis past history and had more comorbidities than other patients. Outpatients were most often Hispanic/Latino. The classical triad (abdominal pain, fever, leukocytosis) occurred in 78 (38.6%) inpatients, 29 (5.2%) outpatients and 34 (10.7%) emergency department cases. Computed tomography was performed on 196 (94.4%) inpatients, 110 (9.2%) outpatients and 296 (87.6%) emergency department cases and was diagnostic in 153 (78.6%) inpatients, 62 (56.4%) outpatients and 243 (82.1%) emergency department cases. Multiple variables affected presenting features. Notably, female sex had lower odds for the presence of the triad features (odds ratio [95% CI], 0.65 [0.45-0.94], P<0.05) and increased odds of vomiting (1.78 [1.26-2.53], P<0.01). Patients in age group 56 to 65 and 66 or older had decreased odds of fever (0.67 [0.46-0.98], P<0.05) and 0.46 [0.26-0.81], P<0.01), respectively, while > / =1 co-morbidity increased the odds of observing the triad (1.88 [1.26-2.81], P<0.01).
  
  
  CONCLUSIONS
  There was little objective evidence for physician-diagnosed diverticulitis in most outpatients. Demographic and clinical characteristics vary among settings and independently affect presenting features.
authors.affiliation: Department of Research and Evaluation Kaiser Permanente Southern California, Pasadena, CA, USA.
authors.forename: Rajan
authors.initials: R
authors.lastname: Iyer
authors.affiliation: Department of Research and Evaluation Kaiser Permanente Southern California, Pasadena, CA, USA.
authors.forename: George F
authors.initials: GF
authors.lastname: Longstreth
authors.affiliation: Department of Research and Evaluation Kaiser Permanente Southern California, Pasadena, CA, USA.
authors.forename: Li-Hao
authors.initials: LH
authors.lastname: Chu
authors.affiliation: Department of Research and Evaluation Kaiser Permanente Southern California, Pasadena, CA, USA.
authors.forename: Wansu
authors.initials: W
authors.lastname: Chen
authors.affiliation: Global Health Economics and Outcomes Research Shire Development LLC, Wayne, PA, USA.
authors.forename: Linnette
authors.initials: L
authors.lastname: Yen
authors.affiliation: Global Health Economics and Outcomes Research Shire Development LLC, Wayne, PA, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Hodgkins
authors.affiliation: Department of Research and Evaluation Kaiser Permanente Southern California, Pasadena, CA, USA. Aniket.A.Kawatkar@kp.org.
authors.forename: Aniket A
authors.initials: AA
authors.lastname: Kawatkar
mesh_terms: D015746:Abdominal Pain / Q000175:diagnosis / Q000453:epidemiology; D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000553:Ambulatory Care; D002140:California / Q000453:epidemiology; D015897:Comorbidity; D019033:Delivery of Health Care, Integrated; D004239:Diverticulitis, Colonic / Q000175:diagnosis* / Q000453:epidemiology*; D004636:Emergency Service, Hospital; D005260:Female; D005334:Fever / Q000175:diagnosis / Q000453:epidemiology; D006801:Humans; D007297:Inpatients; D007964:Leukocytosis / Q000175:diagnosis / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008329:Managed Care Programs; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D010045:Outpatients; D011237:Predictive Value of Tests; D011379:Prognosis; D044469:Racial Groups; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D014057:Tomography, X-Ray Computed; D055815:Young Adult