Partial Mayo Score Calculator
Partial Mayo Score Calculator
The three non-endoscopic Mayo items, 0 to 9, for the visits where no endoscopy is done. It is a strict subset of the full score, not a substitute for it, and three different remission thresholds are in print.
Partial Mayo score
3 subscores → 0–93 to 4 stools more than normal (2), streaks of blood less than half the time (1), moderate global assessment (2)
Scoring
Full Mayo = partial Mayo + endoscopic subscore (0–3)
Remission: 2 or less (commonest) · under 1 (ECCO-ESGAR) · 2 or less with no subscore above 1 and rectal bleeding 0 (tofacitinib stable-remission protocol)
- a strict subset, by construction
- the full Mayo score is exactly this score plus the endoscopic subscore. So the partial score can never exceed the full one and the two differ by between 0 and 3 points. The arithmetic is trivial; the consequence is not, because the 3 points it omits are the only ones that measure the mucosa
- three remission thresholds in print
- 2 or less is the commonest and the one validated against endoscopy in 171 patients. ECCO-ESGAR writes “under 1”. The tofacitinib stable-remission protocol requires 2 or less plus no subscore above 1 plus rectal bleeding of 0. They are not small differences: a patient scoring 2 is in remission under the first and not under the other two
- NOT the modified Mayo
- the modified Mayo score also runs 0–9 but drops the physician’s global assessment and KEEPS the endoscopy — the opposite trade. LUCENT 1 uses a modified score of 4 to 9 for entry. A “9-point Mayo” is ambiguous without saying which item was removed
- it cannot measure mucosal healing
- mucosal healing is defined on the endoscopic subscore, which is the one item this score does not contain. Against a subscore of 0 the partial score reached an area under the curve of 0.823, and against 0 or 1, 0.927, in 171 prospectively studied patients
Worked example
3 to 4 stools more than normal (2), streaks of blood less than half the time (1), moderate global assessment (2)
2 + 1 + 2 = 5 points
5 is above the remission threshold on all three definitions in print
If this patient's endoscopic subscore were 2, the full Mayo score would be 5 + 2 = 7 — the partial score is always the full one minus the endoscopic subscore, so it can understate by up to 3 points
Those 3 points are the only ones in the full score that measure the mucosa, which is why the two are not interchangeable even though one contains the other
A fall to 2 would meet the commonest remission threshold but would still carry a rectal bleeding subscore unless the bleeding had stopped, and several protocols require that subscore to be 0
The three remission thresholds in print
| Threshold | Source | What it admits |
|---|---|---|
| Total 2 or less | The commonest; used in the 171-patient prospective study of partial Mayo against endoscopy | A patient with any combination summing to 2, including a global assessment of 2 alone. |
| Total under 1 | ECCO-ESGAR 2018 | Effectively a total of 0. The strictest of the three by a wide margin. |
| Total 2 or less, no subscore above 1, rectal bleeding 0 | Tofacitinib stable-remission protocol (NCT03281304), inclusion criterion 2a | Excludes any patient still passing blood, whatever the total. |
| Response: fall of 3 or more points and 30% or more | Trial convention for the total Mayo, applied to the partial score as well | Needs a baseline, so it says nothing about a single visit. |
What the partial score predicts about the mucosa
| Endpoint | Area under the curve | Cohort |
|---|---|---|
| Mayo endoscopic subscore of 0 | 0.823 | 171 consecutive patients, prospective |
| Mayo endoscopic subscore of 0 or 1 | 0.927 | The same 171 patients |
| Baron score of 0 | 0.788 | The same 171 patients |
| Baron score of 0 or 1 | 0.902 | The same 171 patients |
The score for the visit with no endoscopy
Most ulcerative colitis visits do not include an endoscopy, and the full Mayo score cannot be completed without one. The partial Mayo score is the obvious answer: keep the three items a clinic can gather — stool frequency against the patient’s own normal, rectal bleeding, and the physician’s global assessment — and drop the fourth. The arithmetic is a strict subset of the full Mayo score, so the partial score is always the full score minus the endoscopic subscore, and the two differ by between 0 and 3 points.
That subset relationship is why the two scores are not interchangeable, and the reason is not about magnitude. The 3 points the partial score omits are the only points in the whole instrument that measure the mucosa. A patient can score 1 on the partial Mayo with an endoscopic subscore of 3, and the trial endpoint everyone cares about — mucosal healing — is defined on that subscore alone. So the partial score answers “how is this patient” and the Mayo endoscopic subscore interpreter answers “what does the bowel look like”, and they can disagree.
How well does it predict the mucosa? In 171 consecutive patients studied prospectively, a partial Mayo of 2 or less predicted an endoscopic subscore of 0 with an area under the curve of 0.823, and a subscore of 0 or 1 with 0.927. Against the Baron score the figures were 0.788 and 0.902. The pattern matters more than the numbers: the partial score tracks the looser definition of healing well and the stricter one noticeably less well, which is exactly what a symptom score should do, because symptoms settle before the mucosa does.
Three remission thresholds are in print and they are not minor variants of each other. Two or less is the commonest and the one tested in that 171-patient study. ECCO-ESGAR writes that a partial Mayo score under 1 indicates remission, which is effectively a total of 0. The tofacitinib stable-remission protocol requires 2 or less together with no individual subscore above 1 and a rectal bleeding subscore of 0. A patient scoring exactly 2 is in remission under the first and not under either of the others. One more naming trap: the MODIFIED Mayo score also runs 0 to 9, but it drops the global assessment and keeps the endoscopy — the opposite trade to this one — so “a Mayo score of 6 out of 9” does not identify a patient. This index scores symptoms, not inflammation. It can be high with a normal mucosa — bile-acid diarrhoea, a stricture, bacterial overgrowth, coexisting irritable bowel syndrome — and low with active endoscopic disease. That mismatch is why treat-to-target moved off symptom indices and onto objective markers. The faecal calprotectin interpreter and the CRP unit converter are what to add at a visit with no endoscopy. 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 is the difference between the partial and the full Mayo score?
The partial score is the full score minus the endoscopic subscore. It runs 0 to 9 rather than 0 to 12 and uses stool frequency, rectal bleeding and the physician’s global assessment. Because the omitted 3 points are the only ones that measure the mucosa, the two are not interchangeable: a patient can be at 1 on the partial score with an endoscopic subscore of 3.
What partial Mayo score counts as remission?
Three thresholds are in print. Two or less is the commonest and the one tested against endoscopy in 171 patients. ECCO-ESGAR writes “under 1”. The tofacitinib stable-remission protocol requires 2 or less plus no subscore above 1 plus a rectal bleeding subscore of 0. A patient scoring 2 is in remission under the first and not under the others, so say which you are using.
Is the partial Mayo score the same as the modified Mayo score?
No, although both run 0 to 9. The partial score drops the endoscopy; the modified score drops the physician’s global assessment and keeps the endoscopy. LUCENT 1 uses a modified score of 4 to 9 for entry. A 9-point Mayo score quoted without saying which item was removed cannot be interpreted.
Can a partial Mayo score tell me whether the mucosa has healed?
Only probabilistically, and it is better at the looser definition than the stricter one. A partial Mayo of 2 or less predicted an endoscopic subscore of 0 with an area under the curve of 0.823 and a subscore of 0 or 1 with 0.927 in 171 prospectively studied patients. Mucosal healing itself is defined on the endoscopic subscore, which this score does not contain.
How is stool frequency scored?
Against the patient’s own normal daily number, not an absolute count: 1 to 2 more than normal scores 1, 3 to 4 more scores 2, and 5 or more scores 3. In the trials it is the average over the three days before the visit, rounded, minus the patient’s reported normal. Scoring it absolutely misclassifies anyone whose baseline was not one or two stools a day.
Related calculators
References
- Pfizer. Statistical Analysis Plan, A3921139 (OCTAVE Open), Appendix 2.1: Mayo scoring system. NCT01470612, clinicaltrials.gov.
- ECCO congress abstract P364. Patient-reported outcomes, partial Mayo score and SCCAI are equally accurate in predicting mucosal healing in UC: final results from a prospective study. ecco-ibd.eu.
- 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
- Boehringer Ingelheim. A Phase II study in patients with moderate to severe active ulcerative colitis — protocol, Sections 1.4.1 and 7.2.5: full, partial and modified Mayo scores. NCT03675477, clinicaltrials.gov.
- Takeda. Clinical Study Protocol MLN0002-3026 (VARSITY), Sections 5.2.1, 5.2.2 and 9.1.6. NCT02497469, clinicaltrials.gov.
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/