How four outcome questionnaires get scored, and when the score should not be trusted
Published · 6 min read
A rehabilitation programme that captures patient reported outcomes has to answer two questions that pull against each other. How often do you ask, and when is the answer solid enough to show somebody.
The ACL programme we publish carries four instruments across 42 days and 101 check-ins. How they are spaced is a design decision, and it is visible in the published data.
The four, and what each is for
| Instrument | What it measures | Burden on the patient |
|---|---|---|
| EQ-5D-5L | Health related quality of life, general | Moderate |
| KOOS | Knee injury and osteoarthritis outcome | High |
| IKDC | Subjective knee function | High |
| VAS | Pain, right now | Very low |
The first three are established instruments with their own scoring rules. VAS is a single number between 0 and 10.
Why three of them appear once and one appears daily
On day 1 of the programme, all four are captured. That is the baseline.
From day 11 onward the sample days carry VAS alone, once at the start of the day and once at the end. None of KOOS, IKDC and EQ-5D-5L appears on the published sample days from the middle of the programme.
This is deliberate and it is about response quality, not convenience. KOOS is a long form. Asked daily, completion collapses and the answers that do arrive get worse, because a patient filling in the same long form for the eleventh time is pattern matching rather than reporting. Asked twice, before and after, it produces a comparison people will actually trust.
VAS survives daily use because it is one question. That makes it the only instrument in the set that can carry a trend line rather than two endpoints.
Twice a day, not once
The sample days open and close with VAS. Pain measured in the morning and pain measured after the session are different numbers, and the difference between them is more informative than either alone.
A pain score that rises across a session is a different signal from one that is simply high.
Blending them into one number, carefully
The programme level recovery score runs 0 to 100 and blends its components into one figure.
Each component is reported with its own raw start and end values beside the blended figure. A single number is useful at a glance and dangerous on its own, so the parts stay visible.
When the number should not be shown
This is the part that matters more than the scoring formula.
Every score carries a confidence margin and a data sufficiency flag. When the underlying data is thin, the score is labelled as limited or preliminary, and the category that is missing is named.
The reason is simple. An average built on three answers looks exactly like an average built on three hundred, and a clinician reading it has no way to tell which one they are looking at unless the system says so. A confident wrong number is worse than a gap, because a gap prompts a question and a wrong number ends one.
So the rule in the platform is that a number is shown when the data supports it, and labelled when it does not. We would rather show a clinician a gap than a confident average built on three answers.
What this does not do
Scoring is not interpretation. The platform computes, flags and reports. Whether a score means a patient should progress, repeat a day or stop is a clinical judgement, and it belongs to the clinician responsible for that patient.
The system's job is to make sure that judgement is made against honest numbers.
Where it lives
Outcome capture is part of the rehabilitation module, and the same questionnaire engine drives the surveys and PROMs module on the platform outside rehabilitation.
To see the reporting against your own outcome measures, request a demo.
Programme content is written and assigned by the treating hospital or clinic. Ormeda provides the platform and the content library. Clinical decisions, including whether a programme suits a patient, are made by the clinician responsible for that patient.