Truelove and Witts Severity Index for Ulcerative Colitis
The Truelove and Witts Severity Index is the foundational clinical tool used to assess the severity of an acute flare of Ulcerative Colitis (UC). First published in 1955 by Sidney Truelove and Leslie Witts, it remains the “gold standard” in clinical practice for identifying patients who require hospitalization and intensive corticosteroid therapy.
Unlike more modern scores that require endoscopy (like the Mayo Score), the Truelove and Witts criteria rely entirely on bedside clinical parameters and basic blood tests.
1. The Scoring Criteria
The index categorizes a patient’s condition into three levels: Mild, Moderate, and Severe. A “Severe” classification is often referred to as Acute Severe Ulcerative Colitis (ASUC), which is a medical emergency.
| Variable | Mild | Moderate | Severe (ASUC) |
| Bowel Movements (per day) | < 4 | 4 – 6 | ≥ 6 |
| Blood in Stool | Trace/None | Between Mild/Severe | Visible/Massive |
| Temperature (Pyrexia) | Normal | Intermediate | > 37.5°C (mean) |
| Pulse Rate (Tachycardia) | Normal | Intermediate | > 90 bpm |
| Hemoglobin (Anemia) | Normal | > 75% of normal | < 75% of normal |
| ESR (Inflammation) | < 30 mm/hr | Intermediate | > 30 mm/hr |
2. Clinical Application and “The Rule of 6”
In modern gastroenterology, the “Severe” category is the most critical for decision-making. Physicians often look for the “Rule of 6”:
- 6 or more bloody stools per day * PLUS at least one marker of systemic toxicity (fever, tachycardia, anemia, or high ESR/CRP).
Why it matters:
Patients meeting the “Severe” criteria have a high risk of toxic megacolon or bowel perforation. According to the original study and subsequent validations, these patients should be:
- Admitted to the hospital immediately.
- Started on intravenous (IV) corticosteroids.
- Monitored closely for “rescue therapy” (e.g., Infliximab or Cyclosporine) if they don’t respond within 3 days.
3. Strengths and Limitations
Strengths
- Speed: No need to wait for a colonoscopy or biopsy.
- Prognostic Value: Accurately predicts the likelihood of needing a colectomy (surgical removal of the colon).
- Timelessness: Despite being 70 years old, it correlates highly with modern biomarkers like C-Reactive Protein (CRP) and Fecal Calprotectin.
Limitations
- Subjectivity: The “Moderate” category is poorly defined and often used as a “catch-all” for patients who don’t fit Mild or Severe.
- Lack of Endoscopy: It does not account for mucosal healing, which is the current long-term goal of UC treatment.
4. Modern Adaptations: The Travis Criteria
While Truelove and Witts identify the flare at admission, the Oxford (Travis) Criteria are used on Day 3 of treatment to predict failure. If a patient still has > 8 stools/day or 3–8 stools/day with a CRP > 45 mg/L, there is an 85% chance they will require a colectomy during that admission.
5. References and Resources
Primary Reference
- Truelove SC, Witts LJ. (1955). Cortisone in ulcerative colitis; final report on a therapeutic trial. British Medical Journal, 2(4947), 1041–1048. View via PubMed
Clinical Guidelines
- British Society of Gastroenterology (BSG): Guidelines for the management of inflammatory bowel disease in adults
- European Crohn’s and Colitis Organisation (ECCO): Direct access to UC Guidelines
