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    Mayo Score / Disease Activity Index (DAI) for Ulcerative Colitis

    Assesses severity of ulcerative colitis.
    When to Use
    Why Use
    • Patients with known ulcerative colitis, particularly when considering changing, adding, or stopping a UC medication; this is not a tool to diagnose ulcerative colitis.
    • The Mayo Score is the most commonly used scoring system for UC in clinical trials and routine practice. (Paine 2014)
    • The Mayo Score for Ulcerative Colitis was developed to standardize the severity of a patient's ulcerative colitis (UC) symptoms, which is particularly helpful to assess response to treatment over time.
    • The Mayo Score for Ulcerative Colitis was originally devised in 1987 for a clinical trial for pH dependent 5-ASA (Asacol) at the Mayo Clinic.
    • Comprised of 4 parts: stool frequency, rectal bleeding, endoscopic findings and physician’s global assessment, each scored from 0-3.
    • The physician’s global assessment accounts for other signs/symptoms including abdominal pain, physical exam findings (extraintestinal manifestations, fever, tachycardia), functional status, and the patient’s overall sense of well being.
    • Total scores range from 0-12 with higher scores indicating increased severity of disease.
    • Response to therapy is defined differently in each trial, but most use a decrease of 3 or more points.
      • Remission is often defined as a total score of 2 or less with all individual categories ≤1. Occasionally, remission is defined stringently as a score of 0.
      • Most clinical trials define mucosal healing as an endoscopic score of 0 or 1, although numerous other endoscopic scoring systems exist (D’Haens 20074).
    • The “Full” or “Complete” Mayo score incorporates all 4 parts.
    • If endoscopic findings are not available, the remaining 3 categories constitute a “Modified” or “Partial” Mayo score.

    Points to keep in mind:

    • For stool frequency and rectal bleeding, the patient acts as their own point of reference (i.e. number of stools above normal) rather than the absolute number.
    • Critics point out an element of subjectivity in the Physician’s Global Assessment (sense of well being).
    • The score is not designed to predict need for admission or surgical therapy.
    • This is not a tool to diagnose ulcerative colitis, rather a tool to evaluate patients with known UC.
    • Assesses initial disease severity, change in activity over time, and response to treatment.
    • Provides a universal metric to encapsulate disease severity at a given time in a single number.

    Similar calcs:

    • Nearly identical to the UC Disease Activity Index (DAI) devised by Sutherland et al. Both scores were released in 1987 as objective measures to examine the effects of salicylates in UC. Both rely on the same 4 categories but have miniscule differences in their point assignments


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    • Not designed to predict need for admission or surgical therapy
    • However, an endoscopic score of 0 is associated with lower risk of colectomy compared to higher scores. (Manginot 2016)

    Critical Actions

    If endoscopic data are not available, the modified Mayo score performs equally well. (Lewis 2008)


    Addition of the selected points.

    Facts & Figures

    Criteria Point Value
    Stool Frequency
    Normal 0
    1–2 stools/day more than normal +1
    3–4 stools/day more than normal +2
    >4 stools/day more than normal +3
    Rectal bleeding*
    None 0
    Visible blood with stool less than half the time +1
    Visible blood with stool half of the time or more +2
    Passing blood alone +3
    Mucosal appearance at endoscopy
    Normal or inactive disease 0
    Mild disease (erythema, decreased vascular pattern, mild friability) +1
    Moderate disease (marked erythema, absent vascular pattern, friability, erosions) +2
    Severe disease (spontaneous bleeding, ulceration) +3
    Physician rating of disease activity
    Normal 0
    Mild +1
    Moderate +2
    Severe +3

    *Assigning a score of 3 requires patients to have ≥50% of bowel movement accompanied by visible blood and 1+ bowel movement with blood alone.

    Score interpretation:

    • The higher the score, the more severe the case of ulcerative colitis.
    • The highest score possible is a 12.
    • Scores should be compared to previous scores taken for a patient.
    • The mucosal appearance at endoscopy is not included in the Partial Mayo Score.

    Evidence Appraisal

    • The Mayo score was described by Schroeder et al. in 1987 as a means of assessing response to pH dependent 5-ASA therapy (Asacol) in a randomized that included 87 patients. It was designed to be simple to calculate at the bedside but does include endoscopic findings.
    • The Mayo score remains unvalidated but correlates closely with quality of life. (Irvine 1994)
    • Numerous other scoring systems for UC disease severity exist and some have been validated. (Travis 2013)
    • Despite lack of formal validation, the Mayo Score remains a common assessment tool for ulcerative colitis in current research. (Sandborn 2016)


    Other References

    Research PaperLewis JD, et. al. Use of the Non-invasive Components of the Mayo Score to Assess Clinical Response in Ulcerative Colitis. Inflamm Bowel Dis. Dec 2008; 14(12): 1660–1666. doi: 10.1002/ibd.20520.Research PaperSutherland LR, et al. 5-Aminosalicylic acid enema in the treatment of distal ulcerative colitis, proctosigmoiditis, and proctitis. Gastroenterology 92.6; 1987: 1894-1898.Research PaperPaine ER. Colonoscopic evaluation in ulcerative colitis. Gastroenterology report 2.3; 2014: 161-168.Research PaperD’Haens G, et al. A review of activity indices and efficacy end points for clinical trials of medical therapy in adults with ulcerative colitis. Gastroenterology 132.2; 2007: 763-786.Research PaperManginot C et al. An endoscopic Mayo score of 0 is associated with a lower risk of colectomy than a score of 1 in ulcerative colitis. Gut 64.7; 2015: 1181.Research PaperIrvine EJ, et al. Quality of life: a valid and reliable measure of therapeutic efficacy in the treatment of inflammatory bowel disease. Canadian Crohn's Relapse Prevention Trial Study Group. Gastroenterology 106.2; 1994: 287-296.Research PaperSandborn WJ, et al. Ozanimod Induction and Maintenance Treatment for Ulcerative Colitis. New England Journal of Medicine 374.18; 2016: 1754-1762.
    Dr. Kenneth W. Schroeder

    About the Creator

    Kenneth W. Schroeder, MD, is an associate professor of medicine, specifically in gastroenterology and hepatology the Mayo Clinic. Dr. Schroeder researches endoscopic diagnosis/treatment of GI diseases and inflammatory bowel disease.

    To view Dr. Kenneth W. Schroeder's publications, visit PubMed

    Content Contributors
    • John Vizuete, MD
    About the Creator
    Dr. Kenneth W. Schroeder
    Content Contributors
    • John Vizuete, MD