Oxford Day-3 Criteria Interpreter for Severe Colitis
Oxford Day-3 Criteria Interpreter for Severe Colitis
Two numbers on the third day of intravenous corticosteroid — the stool count and the CRP — that identified a group of whom 85% came to colectomy in the 51 Oxford episodes they were derived in.
Oxford day-3 criteria
Day-3 stools + CRP → readingSix stools in the 24 hours of day 3 of intravenous corticosteroid, CRP 60 mg/L
The two arms
stool frequency more than 8 in 24 h
OR
stool frequency 3 to 8 in 24 h AND CRP above 45 mg/L
85% of patients meeting either arm underwent colectomy during that admission — 51 consecutive episodes in 49 patients, John Radcliffe Hospital, Oxford
- day 3, and only day 3
- the criteria were derived on the third day of intravenous treatment of an attack that met Truelove and Witts on admission. The paper reports that stool frequency and CRP discriminated outcomes over the first five days, but the thresholds above belong to day 3. Reading them on day 1 or day 6 is using them outside their derivation
- the CRP only matters in one arm
- above 8 stools the count satisfies the index by itself. Below 3 stools neither arm applies. The CRP threshold of 45 mg/L does its work in the 3-to-8 window, which is exactly the patient who looks to be improving
- two of 36 variables
- the study monitored 36 clinical, laboratory and radiographic variables and only stool frequency and CRP distinguished the outcome groups, at p below 0.00625 after correction for multiple comparisons. That is the strongest thing about the index and the reason it is still used
- 51 episodes, one centre, pre-biologic
- the 85% figure comes from 51 consecutive episodes in 49 patients at a single hospital, at a time when the only rescue therapy available was cyclosporine, given in 14 of the 51. Four of those 14 avoided colectomy. A modern cohort with infliximab available is not the cohort this figure describes
- it predicts; it does not prescribe
- the criteria identify a group at high risk of colectomy during that admission. What follows is a decision about rescue therapy and surgical timing that belongs to the team and the patient, and this page does not make it
Worked example
Six stools in the 24 hours of day 3 of intravenous corticosteroid, CRP 60 mg/L
Six stools is not more than 8, so the first arm is not satisfied
Six is inside the 3-to-8 window and the CRP of 60 mg/L is above 45 → the second arm is satisfied
In the 51 Oxford episodes, 85% of patients meeting either arm came to colectomy during that admission
This is the arm that matters clinically: the stool count has halved from the admission criterion and looks like improvement, and the CRP says otherwise. A stool count alone would have called this patient better
If the same CRP of 60 mg/L were entered as 6 with the unit left on mg/dL, it would read as 6 mg/L and the criteria would appear unmet — which is why the unit is an explicit choice on this page
The derivation cohort and what happened in it
| Group | Episodes | Outcome |
|---|---|---|
| Meeting either day-3 criterion | Not separately reported | 85% underwent colectomy during that admission. |
| Complete response by day 7 (3 or fewer stools, no visible blood) | 21 of 51 | Median nine months of remission; about 5% chance of colectomy. |
| Incomplete response by day 7 (more than 3 stools or visible blood, no colectomy) | 15 of 51 | 60% chance of continuing symptoms; 40% chance of colectomy. |
| Colectomy during that admission | 15 of 51 | About 29% of all episodes. |
| Given cyclosporine | 14 of 51 | 4 avoided colectomy; 2 continued to have symptoms. The paper says its role remained to be defined. |
What each arm catches
| Day-3 stool count | CRP at or below 45 mg/L | CRP above 45 mg/L |
|---|---|---|
| More than 8 | Criteria met (stool arm) | Criteria met (stool arm) |
| 3 to 8 | Criteria not met | Criteria met (stool-and-CRP arm) |
| Fewer than 3 | Outside the derivation range | Outside the derivation range — the CRP arm requires 3 to 8 stools alongside it |
Day 3 is the question the admission criteria cannot answer
Meeting the Truelove and Witts criteria criteria starts intravenous corticosteroid. It says nothing about whether that treatment will work, and about a quarter of patients admitted with an acute severe attack come to colectomy during the admission. The clinically useful calculation in acute severe colitis is therefore not the one made on admission but the one made on the third day, and Travis and colleagues published it in Gut in 1996.
They followed 51 consecutive episodes of severe colitis in 49 patients at the John Radcliffe Hospital, all admitted on Truelove and Witts criteria, and monitored 36 clinical, laboratory and radiographic variables. Only two discriminated between the outcome groups over the first five days: the stool frequency and the CRP, at p below 0.00625 after correction for multiple comparisons. On day 3, either more than 8 stools, or a stool frequency of 3 to 8 together with a CRP above 45 mg/L, identified a group of whom 85% underwent colectomy during that admission.
The second arm is the one that earns the index its place. A patient admitted with ten bloody stools a day who is down to six on day 3 looks like a responder on the stool chart alone — and if the CRP is still 60 mg/L, that appearance is wrong. The whole value of the rule is that it refuses to read a halved stool count as improvement while the inflammatory marker says otherwise, and the CRP unit converter matters here because 45 mg/L is 4.5 mg/dL and a laboratory reporting mg/dL will print a number nine times smaller than the threshold expects.
Three limits to hold on to. First, the cohort is 51 episodes at one hospital, and the only rescue therapy available was cyclosporine, given in 14 of the 51, of whom 4 avoided colectomy — so the 85% describes a natural history that was already being modified and that modern rescue therapy modifies further. Second, the thresholds belong to day 3: the paper’s day-7 response definitions are different numbers describing different groups, and of the 51 episodes, 21 complete responders by day 7 had a median nine months of remission and about a 5% colectomy risk while 15 incomplete responders faced 40% colectomy and 60% continuing symptoms. Third, the criteria predict; they do not prescribe. This page computes the reading and names the cohort, and the decision about rescue therapy or surgical timing is not a calculation. Outside an acute attack the Mayo score is the instrument the trial literature uses, and the faecal calprotectin interpreter is what tracks inflammation between endoscopies. A score is not a diagnosis and a figure from a cohort is not a probability for one patient. This states what the number meant in a named study; the clinician in front of the patient decides what follows. Thresholds here are the published ones; reference intervals and assay units are method- and laboratory-dependent and your own laboratory’s interval takes precedence.
Frequently asked questions
What are the Oxford day-3 criteria?
On the third day of intravenous corticosteroid for an acute severe attack: more than 8 stools in 24 hours, or a stool frequency of 3 to 8 together with a CRP above 45 mg/L. In the derivation cohort of 51 consecutive episodes at the John Radcliffe Hospital, 85% of patients meeting either arm underwent colectomy during that admission.
Why does the CRP only appear in one arm?
Because above 8 stools the stool count satisfies the index by itself and the CRP adds nothing, and below 3 stools neither arm applies. The CRP threshold does its work in the 3-to-8 window — the patient whose stool frequency has improved into single figures while the inflammation has not settled, who a stool chart alone would call a responder.
Can I apply these criteria on day 2 or day 5?
Not as published. They were derived on day 3, and although the paper reports that stool frequency and CRP discriminated outcomes over the first five days, the thresholds above belong to day 3. The paper’s day-7 figures are different numbers for a different question: complete response at day 7 was 3 or fewer stools with no visible blood.
Is the 85% figure still accurate?
Treat it as the figure from its own cohort. It comes from 51 episodes at a single centre in which the only rescue therapy was cyclosporine, given in 14 episodes, 4 of which avoided colectomy. A contemporary unit with infliximab available is not the population the number was measured in, and a risk from a cohort is not a probability for one patient.
Does meeting the criteria mean rescue therapy or surgery?
This page does not answer that, and no calculation does. What the criteria establish is that the patient belongs to a group with a high rate of colectomy during that admission in the cohort they were derived in. The decision, its timing and the choice between options belong to the gastroenterology and colorectal team and the patient.
Related calculators
References
- Travis SPL, Farrant JM, Ricketts C, et al. Predicting outcome in severe ulcerative colitis. Gut. 1996;38(6):905–10 (abstract).
- NHS Borders. Acute severe colitis — gastroenterology clinical guideline. rightdecisions.scot.nhs.uk.
- Jain S, Kedia S, Bopanna S, et al. Are Truelove and Witts criteria for diagnosing acute severe colitis relevant for the Indian population? A prospective study. Intest Res. 2018;16(1):69–74.
- Sturm A, Maaser C, Calabrese E, et al. ECCO-ESGAR guideline for diagnostic assessment in IBD part 2: IBD scores and general principles and technical aspects. J Crohns Colitis. 2019;13(3):273–84. doi:10.1093/ecco-jcc/jjy114
Not medical advice. For healthcare professionals and education. Reference intervals vary by laboratory and assay — always use your own laboratory's. Never base a dose or a treatment decision on this page alone. Full disclaimer at calcengines.com/disclaimer/