Optimization of a Scoring System to Predict Microscopic Colitis in a Cohort of Patients With Chronic Diarrhea

Thomas G. Cotter, Moritz Binder, Eugene P. Harper, Thomas C. Smyrk, Darrell S. Pardi

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


Goals: Our aim was to develop a scoring system to predict risk of microscopic colitis (MC), to identify patients at low risk, potentially avoiding unnecessary biopsies. Background: Patients with chronic diarrhea often undergo colonoscopy with biopsy, but few have histologic abnormalities. Study: We conducted a retrospective study of patients with chronic diarrhea and a macroscopically normal colonoscopy at our institution over a 9-month period. Multivariable logistic regression assessed the association between predictors and the presence of biopsy-proven MC. Results: The derivation cohort included 617 patients. Median age was 55.1 (39.6 to 68.1) years; 397 (64.3%) were female and 81 (13.1%) had MC. Age ≥55 years, duration of diarrhea ≤6 months, ≥5 bowel movements per day, body mass index <30 kg/m2, current smoking, and current use of selective serotonin reuptake inhibitors/serotonin-norepinephrine reuptake inhibitorss and non-steroidal anti-inflammatory drugs were independently associated with MC. A score of ≥10 points in our scoring system, yielded an area under the ROC curve (AUC) of 0.83 with a sensitivity of 93% and specificity of 49% in predicting which patients have MC. The negative predictive value (NPV) was 97.8% (95.0% to 99.1%). In the validation cohort, the scoring system performed similarly (AUC 0.79, sensitivity 91%, specificity 49%, NPV 97%). By avoiding biopsies in patients at low risk of having MC, costs associated with colon biopsies could be reduced by almost 43%. Conclusion: This scoring system including 7 clinical variables was able to identify patients unlikely to have MC, with excellent sensitivity, reasonable specificity, and a high NPV, translating into important potential cost savings.

Original languageEnglish (US)
Pages (from-to)228-234
Number of pages7
JournalJournal of Clinical Gastroenterology
Issue number3
StatePublished - 2017
Externally publishedYes


  • collagenous colitis
  • lymphocytic colitis
  • random biopsies
  • scoring system

ASJC Scopus subject areas

  • Gastroenterology


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