The Global Rating of Change, a One-Question Check
SaveThere is no single GROC. The number of answer options — three, seven, eleven, fifteen — is chosen by whoever wrote the form, and every interpretation threshold moves with it. A rating of 2 counts as meaningful improvement on an eleven-point version and falls short on a fifteen-point one. The first question worth asking about a global rating is which scale it was written on.
Last updated: July 2026
What does the global rating of change ask?
It asks one question. The global rating of change is a single-item transition question: the patient compares their current state with a named baseline and rates the difference 1Ref 1Kamper SJ, Maher CG, Mackay G. (2009).Global Rating of Change Scales: A Review of Strengths and Weaknesses and Considerations for Design.That the GROC is a single-item transition question comparing current state with a named baseline; that its response format is not fixed (3-, 7-, 11- and 15-point versions, with the 3-point form flagged as problematic and 7 to 11 points described as the best compromise); its signed direction (negative = deterioration, 0 = no change, positive = improvement); and its format-specific thresholds — MDC 0.45 and minimal clinically important change of 2 or more points on an 11-point scale, ≥5/≤−5 on the 15-point scale, ≥6 on the 7-point scale — together with the caution that these are largely musculoskeletal and low-back-pain derived and should not be generalised.. The item count is one, which makes it short enough to ask out loud at the end of a visit, with no form and no scoring arithmetic afterwards.
Its direction is signed and runs both ways. Below zero is deterioration, zero is no change, above zero is improvement 1Ref 1Kamper SJ, Maher CG, Mackay G. (2009).Global Rating of Change Scales: A Review of Strengths and Weaknesses and Considerations for Design.That the GROC is a single-item transition question comparing current state with a named baseline; that its response format is not fixed (3-, 7-, 11- and 15-point versions, with the 3-point form flagged as problematic and 7 to 11 points described as the best compromise); its signed direction (negative = deterioration, 0 = no change, positive = improvement); and its format-specific thresholds — MDC 0.45 and minimal clinically important change of 2 or more points on an 11-point scale, ≥5/≤−5 on the 15-point scale, ≥6 on the 7-point scale — together with the caution that these are largely musculoskeletal and low-back-pain derived and should not be generalised.. That two-sidedness is unusual. Most questionnaires measure a state, and change has to be worked out by subtracting one visit's score from another's; the global rating skips the subtraction and asks the patient to make the comparison directly.
A transition question is one that asks about the difference between two points in time rather than about how things are right now. The comparison point is part of the question, which is why "compared with when you started physical therapy" and "compared with last week" are two different questions wearing the same answer options.
Why there is no single GROC scale
How many answer choices a form offers is not settled by the instrument, and this is the most important thing to know about it. The review that defines the measure covers 3-point versions (better, same, worse), 7-point versions, 11-point versions, and 15-point versions running from −7 to +7 1Ref 1Kamper SJ, Maher CG, Mackay G. (2009).Global Rating of Change Scales: A Review of Strengths and Weaknesses and Considerations for Design.That the GROC is a single-item transition question comparing current state with a named baseline; that its response format is not fixed (3-, 7-, 11- and 15-point versions, with the 3-point form flagged as problematic and 7 to 11 points described as the best compromise); its signed direction (negative = deterioration, 0 = no change, positive = improvement); and its format-specific thresholds — MDC 0.45 and minimal clinically important change of 2 or more points on an 11-point scale, ≥5/≤−5 on the 15-point scale, ≥6 on the 7-point scale — together with the caution that these are largely musculoskeletal and low-back-pain derived and should not be generalised.. All of them are global ratings of change. None of them is the global rating of change.
The review is not neutral between those formats. It flags the 3-point version as problematic, and finds that versions offering between seven and eleven points strike the best available balance between what patients prefer and how the scale performs as a measurement 1Ref 1Kamper SJ, Maher CG, Mackay G. (2009).Global Rating of Change Scales: A Review of Strengths and Weaknesses and Considerations for Design.That the GROC is a single-item transition question comparing current state with a named baseline; that its response format is not fixed (3-, 7-, 11- and 15-point versions, with the 3-point form flagged as problematic and 7 to 11 points described as the best compromise); its signed direction (negative = deterioration, 0 = no change, positive = improvement); and its format-specific thresholds — MDC 0.45 and minimal clinically important change of 2 or more points on an 11-point scale, ≥5/≤−5 on the 15-point scale, ≥6 on the 7-point scale — together with the caution that these are largely musculoskeletal and low-back-pain derived and should not be generalised..
Because the range is chosen by whoever designs the form, no interpretation of a GROC number survives being carried across to a different version. A clinic switching forms between two visits has, in effect, changed instruments.
How much change counts as meaningful?
Thresholds do exist, and they belong to the format rather than the instrument. An 11-point version needs 2 points or more before a change counts as clinically important, and its minimal detectable change — the movement exceeding measurement error — is 0.45 points, computed from chronic low back pain data. On a 15-point scale, 5 or more marks meaningful improvement and −5 or lower meaningful deterioration. On a 7-point scale, it is 6 or more 1Ref 1Kamper SJ, Maher CG, Mackay G. (2009).Global Rating of Change Scales: A Review of Strengths and Weaknesses and Considerations for Design.That the GROC is a single-item transition question comparing current state with a named baseline; that its response format is not fixed (3-, 7-, 11- and 15-point versions, with the 3-point form flagged as problematic and 7 to 11 points described as the best compromise); its signed direction (negative = deterioration, 0 = no change, positive = improvement); and its format-specific thresholds — MDC 0.45 and minimal clinically important change of 2 or more points on an 11-point scale, ≥5/≤−5 on the 15-point scale, ≥6 on the 7-point scale — together with the caution that these are largely musculoskeletal and low-back-pain derived and should not be generalised..
| Scale format | What counts as meaningful |
|---|---|
| 7-point | 6 or more, for improvement |
| 11-point | 2 points or more |
| 15-point (−7 to +7) | 5 or more improved; −5 or lower deteriorated |
The minimal detectable change on an 11-point global rating is 0.45 points, far below the 2 points patients call meaningful 1Ref 1Kamper SJ, Maher CG, Mackay G. (2009).Global Rating of Change Scales: A Review of Strengths and Weaknesses and Considerations for Design.That the GROC is a single-item transition question comparing current state with a named baseline; that its response format is not fixed (3-, 7-, 11- and 15-point versions, with the 3-point form flagged as problematic and 7 to 11 points described as the best compromise); its signed direction (negative = deterioration, 0 = no change, positive = improvement); and its format-specific thresholds — MDC 0.45 and minimal clinically important change of 2 or more points on an 11-point scale, ≥5/≤−5 on the 15-point scale, ≥6 on the 7-point scale — together with the caution that these are largely musculoskeletal and low-back-pain derived and should not be generalised.. The gap between those two numbers is the interesting part. This scale can register movement smaller than the movement anyone would care about, which is the reverse of the problem most questionnaires have, where the smallest reliable change is larger than the change that matters.
How the points are labelled also varies between versions 1Ref 1Kamper SJ, Maher CG, Mackay G. (2009).Global Rating of Change Scales: A Review of Strengths and Weaknesses and Considerations for Design.That the GROC is a single-item transition question comparing current state with a named baseline; that its response format is not fixed (3-, 7-, 11- and 15-point versions, with the 3-point form flagged as problematic and 7 to 11 points described as the best compromise); its signed direction (negative = deterioration, 0 = no change, positive = improvement); and its format-specific thresholds — MDC 0.45 and minimal clinically important change of 2 or more points on an 11-point scale, ≥5/≤−5 on the 15-point scale, ≥6 on the 7-point scale — together with the caution that these are largely musculoskeletal and low-back-pain derived and should not be generalised., so the same numeral written on two different forms is not the same rating.
The one question that calibrates the other scales
Its most common job is not measuring the patient. It is measuring the other questionnaires. To establish how many points of change on a longer instrument amount to real improvement, researchers need a reference outside that instrument, and a global rating is usually what they reach for.
The numeric pain rating scale is the clearest case. Its change thresholds in low back pain — 2.2 points at one week and 1.5 points at four weeks — were anchored on a global rating of change, and what the authors took from that is that a 2-point move both clears measurement error and amounts to clinically meaningful improvement 2Ref 2Childs JD, Piva SR, Fritz JM (2005).Responsiveness of the numeric pain rating scale in patients with low back pain.That the numeric pain rating scale's change thresholds in low back pain (2.2 points at one week, 1.5 points at four weeks) were anchored on a global rating of change, and that a 2-point change represents clinically meaningful improvement exceeding measurement error.. The patient-specific functional scale was built on the same footing: the yardstick used to judge whether it moved was a global rating averaged across the patient's view and the clinician's 3Ref 3Stratford P, Gill C, Westaway M, Binkley J. (1995).Assessing Disability and Change on Individual Patients: A Report of a Patient Specific Measure.That the Patient-Specific Functional Scale's sensitivity to change was assessed against an averaged patient and clinician global rating of change in its original validation..
Not every instrument has been through that process. On the Lower Extremity Functional Scale, both figures land on the same value of 9 scale points — the change patients call important, and the change that clears measurement error 4Ref 4Binkley JM, Stratford PW, Lott SA, Riddle DL (1999).The Lower Extremity Functional Scale (LEFS): Scale Development, Measurement Properties, and Clinical Application.That the Lower Extremity Functional Scale reports a minimal clinically important difference and a minimal detectable change of 9 scale points.. The Quebec Back Pain Disability Scale's founding validation, by contrast, demonstrated responsiveness — it detected change over time and separated groups expected to change in opposite directions — without deriving any threshold value at all 5Ref 5Kopec JA, Esdaile JM, Abrahamowicz M, et al. (1995).The Quebec Back Pain Disability Scale. Measurement properties.That the Quebec Back Pain Disability Scale's validation demonstrated responsiveness — detecting change in disability over time and distinguishing groups expected to change in different directions — without establishing any minimal-change threshold.. Where a threshold is quoted for an instrument whose original paper set none, it came from later work, and that work usually leaned on an anchor like this one.
Where a global rating falls short
The published thresholds come from a narrow place. Most were derived in musculoskeletal and low-back-pain samples, and the review is explicit that they should not be quietly carried across to other conditions 1Ref 1Kamper SJ, Maher CG, Mackay G. (2009).Global Rating of Change Scales: A Review of Strengths and Weaknesses and Considerations for Design.That the GROC is a single-item transition question comparing current state with a named baseline; that its response format is not fixed (3-, 7-, 11- and 15-point versions, with the 3-point form flagged as problematic and 7 to 11 points described as the best compromise); its signed direction (negative = deterioration, 0 = no change, positive = improvement); and its format-specific thresholds — MDC 0.45 and minimal clinically important change of 2 or more points on an 11-point scale, ≥5/≤−5 on the 15-point scale, ≥6 on the 7-point scale — together with the caution that these are largely musculoskeletal and low-back-pain derived and should not be generalised.. A cutoff established in chronic low back pain is not automatically the cutoff for recovery after shoulder surgery, or for a condition that behaves nothing like back pain.
The single-item design also carries no detail. A rating of +3 says a person is somewhat better without saying what improved — pain, sleep, walking distance, confidence at work — which is why it sits beside a condition-specific questionnaire rather than in place of one.
Brevity is not the same as crudeness. The tegner activity scale is also a single item, grading work and sport activity on a 0-to-10 gradient where higher means more active 6Ref 6Tegner Y, Lysholm J. (1985).Rating systems in the evaluation of knee ligament injuries.That the Tegner Activity Scale is a single-item grading of work and sport activity on a 0-10 gradient in which higher scores denote higher activity.. One well-built question can carry real information. What no single question can carry is more than one thing at a time.
Reading your own rating, and what a clinic does with it
Answering it is not a test, and there is no score to fail. Zero is a legitimate answer and so is a negative one — a scale deliberately built to run in both directions is a scale that expects some people to be worse. The least useful answer anyone gives is the polite one: a small positive rating offered because the clinician has worked hard and the appointment is nearly over.
Two things make the answer worth more. The first is knowing the comparison point, because "since the injury" and "since last month" pull genuinely different ratings out of the same person. The second is knowing which version of the scale is on the page, since the same numeral means different things across the 7-, 11-, and 15-point forms 1Ref 1Kamper SJ, Maher CG, Mackay G. (2009).Global Rating of Change Scales: A Review of Strengths and Weaknesses and Considerations for Design.That the GROC is a single-item transition question comparing current state with a named baseline; that its response format is not fixed (3-, 7-, 11- and 15-point versions, with the 3-point form flagged as problematic and 7 to 11 points described as the best compromise); its signed direction (negative = deterioration, 0 = no change, positive = improvement); and its format-specific thresholds — MDC 0.45 and minimal clinically important change of 2 or more points on an 11-point scale, ≥5/≤−5 on the 15-point scale, ≥6 on the 7-point scale — together with the caution that these are largely musculoskeletal and low-back-pain derived and should not be generalised..
Many clinics treat the rating as a trigger rather than a grade. A rating that has not moved across several visits is a prompt to examine again, change the plan, or revisit the working diagnosis — which is close to the most a single question can reasonably be asked to do.
Common questions
Related
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How Much Score Change Actually Counts as BetterMuscle, joint & pain
The Patient-Specific Functional Scale: Define Your Own GoalsMuscle, joint & pain
The Upper Extremity Functional Index, Explained
Say it back
How would you explain this to someone you love?
Two or three sentences, just as you’d say it. Gale reflects back what you focused on — a mirror, not a quiz.
Changes that need a clinician rather than a follow-up rating
- —New weakness in a limb — a foot that drags or catches when walking, or a hand that drops objects
- —Numbness in the groin or inner thighs, or new difficulty controlling the bladder or bowels, alongside back pain
- —Pain that has become constant, wakes you every night, and is worsening despite rest, particularly with unexplained weight loss or fever
- —A joint that turns hot, red and swollen over a matter of hours, with fever or chills
Numbness in the groin area or new loss of bladder or bowel control alongside back pain is an emergency — go to the emergency department, and call 911 if leg weakness makes travelling there unsafe.
This page explains how a rating scale works. It is health information, not medical advice. A rating is a report, not an examination, and what it means for you belongs to a clinician who can assess you directly.
References
- 1.Kamper SJ, Maher CG, Mackay G. (2009). Global Rating of Change Scales: A Review of Strengths and Weaknesses and Considerations for Design. The Journal of Manual & Manipulative Therapy, 17(3), 163–170. doi:10.1179/jmt.2009.17.3.163 ✓That the GROC is a single-item transition question comparing current state with a named baseline; that its response format is not fixed (3-, 7-, 11- and 15-point versions, with the 3-point form flagged as problematic and 7 to 11 points described as the best compromise); its signed direction (negative = deterioration, 0 = no change, positive = improvement); and its format-specific thresholds — MDC 0.45 and minimal clinically important change of 2 or more points on an 11-point scale, ≥5/≤−5 on the 15-point scale, ≥6 on the 7-point scale — together with the caution that these are largely musculoskeletal and low-back-pain derived and should not be generalised.
- 2.Childs JD, Piva SR, Fritz JM (2005). Responsiveness of the numeric pain rating scale in patients with low back pain. Spine (Phila Pa 1976). 2005;30(11):1331-4. doi:10.1097/01.brs.0000164099.92112.29 ✓That the numeric pain rating scale's change thresholds in low back pain (2.2 points at one week, 1.5 points at four weeks) were anchored on a global rating of change, and that a 2-point change represents clinically meaningful improvement exceeding measurement error.
- 3.Stratford P, Gill C, Westaway M, Binkley J. (1995). Assessing Disability and Change on Individual Patients: A Report of a Patient Specific Measure. Physiotherapy Canada 47(4):258–263. doi:10.3138/ptc.47.4.258That the Patient-Specific Functional Scale's sensitivity to change was assessed against an averaged patient and clinician global rating of change in its original validation.
- 4.Binkley JM, Stratford PW, Lott SA, Riddle DL (1999). The Lower Extremity Functional Scale (LEFS): Scale Development, Measurement Properties, and Clinical Application. Physical Therapy, 79(4), 371-383. doi:10.1093/ptj/79.4.371 ✓That the Lower Extremity Functional Scale reports a minimal clinically important difference and a minimal detectable change of 9 scale points.
- 5.Kopec JA, Esdaile JM, Abrahamowicz M, et al. (1995). The Quebec Back Pain Disability Scale. Measurement properties. Spine (Phila Pa 1976). 1995;20(3):341-52. doi:10.1097/00007632-199502000-00016 ✓That the Quebec Back Pain Disability Scale's validation demonstrated responsiveness — detecting change in disability over time and distinguishing groups expected to change in different directions — without establishing any minimal-change threshold.
- 6.Tegner Y, Lysholm J. (1985). Rating systems in the evaluation of knee ligament injuries. Clinical Orthopaedics and Related Research, September 1985, issue 198, pages 43-49. doi:10.1097/00003086-198509000-00007 ✓That the Tegner Activity Scale is a single-item grading of work and sport activity on a 0-10 gradient in which higher scores denote higher activity.
6 sources, numbered by first appearance. General health information, not medical advice. AI-assisted editorial content — citations link their sources. Editorial policy