A PROM is the instrument, usually a questionnaire or scale, that records a health outcome directly from the patient, with no interpretation by a clinician or anyone else. The outcome it captures is called a PRO.
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Patient-reported outcome measure
noun · clinical research
An instrument that measures a patient-reported outcome: a report on a health condition that comes directly from the patient, without interpretation by a clinician or anyone else.
Related terms
In short
Explained
The vocabulary around patient-reported data causes more confusion than the concepts. A patient-reported outcome (PRO) is a fact about a person's health as reported by that person: how bad the pain is, how far they can walk, how well they slept. A patient-reported outcome measure (PROM) is the specific questionnaire, scale or diary item used to get that report in a standard, scoreable way. Many people use the two interchangeably, which is harmless in conversation but matters in a protocol.
Contrast this with other types of outcome assessment. A clinician-reported outcome depends on a trained observer's judgement, such as a rater scoring a depression interview. A performance outcome is a task the participant carries out, such as a timed walk. An observer-reported outcome comes from a caregiver. Our page on ClinRO, ObsRO, PerfO and PRO sets the four types side by side.
Generic PROMs measure aspects of health that apply across conditions, such as general quality of life or physical function. Condition-specific PROMs target a disease: a migraine impact scale, an asthma control questionnaire or a symptom diary for a particular cancer treatment. Studies often pair one generic and one specific measure so that results can be compared across populations while still capturing what matters in the condition.
Before choosing, ask five questions. Has it been validated in people like those in the study? What is the recall period (today, past week, past month)? How is it scored and what is the range? Is there an established minimal clinically important difference? And who owns the instrument, because many validated PROMs are copyrighted and need permission or a licence for trial use. Capture does not supply licensed instruments or verify licences; the study team handles permission and keeps the licence with the study documents.
Paper diaries are prone to back-filling, where answers are written in bulk just before a visit. Electronic collection time-stamps each response and can limit the window in which a questionnaire can be completed, which improves confidence in the data. The comparison in paper versus digital PRO goes through the trade-offs.
Daily pain diary on a phone (demo)
Participant 003 · Day 14
Pain at its worst in the last 24 hours
How much did pain interfere with sleep?
Anything else to tell your study team?
Compared
| Type | Reported by | Example |
|---|---|---|
| PRO / PROM | The patient, unaltered | Pain rating, fatigue diary, quality-of-life questionnaire |
| ClinRO | A trained clinician | Rater-administered symptom scale, physician global assessment |
| ObsRO | A parent, partner or carer | Observer diary of seizures or sleep in a child |
| PerfO | Measured from a task performed by the participant | Timed walk, cognitive test |
| PREM | The patient, about the care experience | Questionnaire on communication and waiting |
Instruments in any of these categories may be licensed. Check each rights holder's terms before use.
In Capture
Capture's ePRO module builds diaries and questionnaires with ten question types, including linear scales, sliders, single and multiple choice and free text. Participants complete them on their own device through a link, with no app to install, and the study team can schedule tasks and reminders. Pre-built diary templates (pain, sleep, mood, fatigue and others) are in the template library. Each questionnaire can carry licence details such as number, holder and expiry, which Capture stores but does not verify.
Evening diary
Question 3 of 8
How would you rate your fatigue today?
0 = no fatigue, 10 = worst imaginable
Create the diary, preview it as the participant sees it and test skip logic with sample responses. Free sandbox, every feature, no credit card.
Checklist
Look for validation in the same condition, age group and language. Do not assume a translation exists.
A 7-day recall instrument filled in monthly measures only the last week, not the month.
Write it into the statistical analysis plan before data is collected.
Contact the rights holder, record the terms and keep them in the study documents.
Define how late a response may be and what happens to missing assessments.
Decide how much change counts as important to patients, not only statistically significant.
Patient-reported outcome measure. It is the questionnaire or scale that records an outcome directly from the patient.
The PRO is the outcome being reported, such as pain intensity. The PROM is the instrument used to measure and score it, such as a numeric rating scale.
A PROM measures health status, symptoms or function. A PREM measures the patient's experience of receiving care, such as communication or waiting times. They are not the same, and a PREM is not a satisfaction survey.
Yes. They are common as primary or secondary endpoints, especially where the outcome is how a person feels or functions, such as pain, fatigue or quality of life.
Often yes. Many validated instruments are copyrighted and need permission or a fee for use in trials. Check the rights holder's terms before you build the questionnaire.
Yes. ePRO collection time-stamps each response, limits late completion and removes manual transcription. The instrument's owner may have rules about electronic versions, so check them.
The minimal clinically important difference is the smallest change in score that patients regard as meaningful. It helps judge whether a statistically significant change matters.
Keep exploring
Build, preview and test your questionnaire in the free sandbox. No credit card.