The Boston Questionnaire for Carpal Tunnel

What is the Boston Carpal Tunnel Questionnaire?

It is a self-administered questionnaire published in 1993 and known by several names — the Boston Carpal Tunnel Questionnaire, the Levine-Katz questionnaire, or the Brigham and Women's Carpal Tunnel Questionnaire. All three refer to one instrument. It carries two scales that are scored independently of one another: a Symptom Severity Scale and a Functional Status Scale 1Ref 1Levine DW, Simmons BP, Koris MJ, et al. (1993).A self-administered questionnaire for the assessment of severity of symptoms and functional status in carpal tunnel syndrome.The Boston Carpal Tunnel Questionnaire's construction, structure, scoring and original psychometrics: a self-administered instrument with two independently scored scales, a Symptom Severity Scale and a Functional Status Scale, each item carrying five ordered responses and each scale scored as the mean of its items to give a 1-5 range in which 1 is the best outcome and 5 the worst; reproducibility of 0.91 and 0.93 and internal consistency of 0.89 and 0.91; validity established as positive but modest-to-weak correlations with conventional clinical and electrodiagnostic measures, with the authors concluding that the scales capture outcome dimensions not reflected by traditional clinical measurements; responsiveness in 38 post-operative patients reassessed at about 14 months, symptom severity moving 3.4 to 1.9 and functional status 3 to 2; and the absence in this paper of any MCID, MDC, diagnostic cutoff or severity band..

The separation is deliberate. How much a hand bothers someone and how much it stops them doing things are related but not the same, and in carpal tunnel syndrome they often come apart. A hand can wake its owner three times a night and still manage a full working day. Another can be quiet until it drops a coffee cup.

Self-administered means the score comes entirely from the person's own answers, with nobody measuring anything. No part of these two numbers is produced by an examiner, which is what distinguishes the form from the nerve tests and grip measurements that sit alongside it in a hand clinic.

The questionnaire is the property of its developers, so the wording of its items is not reproduced here. What matters for reading a result is not the exact phrasing of the questions but the shape of the scoring, which is unusually simple and unusually easy to misread.

How the two numbers are worked out

Every item on the form offers five ordered responses, and each scale is scored as the mean of its own items. That puts both scales on the same 1-to-5 range regardless of how many questions each one contains. The direction is stated plainly in the original paper: 1 is the best outcome and 5 is the worst, so a higher number means worse symptoms or worse function 1Ref 1Levine DW, Simmons BP, Koris MJ, et al. (1993).A self-administered questionnaire for the assessment of severity of symptoms and functional status in carpal tunnel syndrome.The Boston Carpal Tunnel Questionnaire's construction, structure, scoring and original psychometrics: a self-administered instrument with two independently scored scales, a Symptom Severity Scale and a Functional Status Scale, each item carrying five ordered responses and each scale scored as the mean of its items to give a 1-5 range in which 1 is the best outcome and 5 the worst; reproducibility of 0.91 and 0.93 and internal consistency of 0.89 and 0.91; validity established as positive but modest-to-weak correlations with conventional clinical and electrodiagnostic measures, with the authors concluding that the scales capture outcome dimensions not reflected by traditional clinical measurements; responsiveness in 38 post-operative patients reassessed at about 14 months, symptom severity moving 3.4 to 1.9 and functional status 3 to 2; and the absence in this paper of any MCID, MDC, diagnostic cutoff or severity band..

On this form the low number is the good one — the opposite of most scores people are used to.

Using a mean rather than a total has a quiet advantage. A questionnaire scored by adding items up changes its range whenever an item is skipped or added; a questionnaire scored by averaging does not. The two scales stay comparable with each other and across studies that use slightly different versions.

It also compresses everything into four points of room. The distance between a 2.4 and a 2.9 looks trivial written down, and on a scale that only runs from 1 to 5 it is not trivial at all. Small decimal movements deserve more attention here than the same decimals would earn on a scale that runs to 100.

Why the score and the nerve test often disagree

Because they are measuring different things, and the original study said so. When the developers checked their new scales against conventional clinical and electrodiagnostic measures, the correlations were positive but modest to weak 1Ref 1Levine DW, Simmons BP, Koris MJ, et al. (1993).A self-administered questionnaire for the assessment of severity of symptoms and functional status in carpal tunnel syndrome.The Boston Carpal Tunnel Questionnaire's construction, structure, scoring and original psychometrics: a self-administered instrument with two independently scored scales, a Symptom Severity Scale and a Functional Status Scale, each item carrying five ordered responses and each scale scored as the mean of its items to give a 1-5 range in which 1 is the best outcome and 5 the worst; reproducibility of 0.91 and 0.93 and internal consistency of 0.89 and 0.91; validity established as positive but modest-to-weak correlations with conventional clinical and electrodiagnostic measures, with the authors concluding that the scales capture outcome dimensions not reflected by traditional clinical measurements; responsiveness in 38 post-operative patients reassessed at about 14 months, symptom severity moving 3.4 to 1.9 and functional status 3 to 2; and the absence in this paper of any MCID, MDC, diagnostic cutoff or severity band.. Their conclusion was not that the questionnaire had failed: it was that these scales capture dimensions of outcome that the traditional measurements do not reflect 1Ref 1Levine DW, Simmons BP, Koris MJ, et al. (1993).A self-administered questionnaire for the assessment of severity of symptoms and functional status in carpal tunnel syndrome.The Boston Carpal Tunnel Questionnaire's construction, structure, scoring and original psychometrics: a self-administered instrument with two independently scored scales, a Symptom Severity Scale and a Functional Status Scale, each item carrying five ordered responses and each scale scored as the mean of its items to give a 1-5 range in which 1 is the best outcome and 5 the worst; reproducibility of 0.91 and 0.93 and internal consistency of 0.89 and 0.91; validity established as positive but modest-to-weak correlations with conventional clinical and electrodiagnostic measures, with the authors concluding that the scales capture outcome dimensions not reflected by traditional clinical measurements; responsiveness in 38 post-operative patients reassessed at about 14 months, symptom severity moving 3.4 to 1.9 and functional status 3 to 2; and the absence in this paper of any MCID, MDC, diagnostic cutoff or severity band..

An electrodiagnostic test measures how well and how fast the median nerve conducts a signal across the wrist. The questionnaire measures what the hand is doing to a person's nights and days. Carpal tunnel syndrome arises when that nerve is compressed at the wrist, producing numbness, tingling and weakness 2Ref 2American Academy of Orthopaedic Surgeons (OrthoInfo) (2024).Carpal Tunnel Syndrome.That carpal tunnel syndrome results from compression of the median nerve at the wrist, producing numbness, tingling and weakness, and that nonsurgical management includes splinting and injections with carpal tunnel release reserved for persistent cases. — and how much a given amount of compression costs a given person is not fixed.

So a mildly abnormal nerve study alongside a badly disrupted hand is not a contradiction, and neither is the reverse. Both findings are real. A clinician holding both is better informed than one holding either.

The form is meanwhile consistent with itself. Reproducibility was 0.91 for symptom severity and 0.93 for functional status, with internal consistency of 0.89 and 0.91 1Ref 1Levine DW, Simmons BP, Koris MJ, et al. (1993).A self-administered questionnaire for the assessment of severity of symptoms and functional status in carpal tunnel syndrome.The Boston Carpal Tunnel Questionnaire's construction, structure, scoring and original psychometrics: a self-administered instrument with two independently scored scales, a Symptom Severity Scale and a Functional Status Scale, each item carrying five ordered responses and each scale scored as the mean of its items to give a 1-5 range in which 1 is the best outcome and 5 the worst; reproducibility of 0.91 and 0.93 and internal consistency of 0.89 and 0.91; validity established as positive but modest-to-weak correlations with conventional clinical and electrodiagnostic measures, with the authors concluding that the scales capture outcome dimensions not reflected by traditional clinical measurements; responsiveness in 38 post-operative patients reassessed at about 14 months, symptom severity moving 3.4 to 1.9 and functional status 3 to 2; and the absence in this paper of any MCID, MDC, diagnostic cutoff or severity band.. Those are strong figures. The disagreement with nerve testing is not noise in the questionnaire; it is a difference in what is being counted.

What the questionnaire cannot do

It cannot diagnose. The paper that defines the instrument establishes no diagnostic cutoffs and no severity bands, because the form was built as a measure of symptom burden and outcome rather than as a screening test. Nothing in it separates people who have the condition from people who do not 1Ref 1Levine DW, Simmons BP, Koris MJ, et al. (1993).A self-administered questionnaire for the assessment of severity of symptoms and functional status in carpal tunnel syndrome.The Boston Carpal Tunnel Questionnaire's construction, structure, scoring and original psychometrics: a self-administered instrument with two independently scored scales, a Symptom Severity Scale and a Functional Status Scale, each item carrying five ordered responses and each scale scored as the mean of its items to give a 1-5 range in which 1 is the best outcome and 5 the worst; reproducibility of 0.91 and 0.93 and internal consistency of 0.89 and 0.91; validity established as positive but modest-to-weak correlations with conventional clinical and electrodiagnostic measures, with the authors concluding that the scales capture outcome dimensions not reflected by traditional clinical measurements; responsiveness in 38 post-operative patients reassessed at about 14 months, symptom severity moving 3.4 to 1.9 and functional status 3 to 2; and the absence in this paper of any MCID, MDC, diagnostic cutoff or severity band..

That rules out a whole category of question. A score does not settle tendonitis vs carpal tunnel. It cannot say which fingers carpal tunnel affects, or whether the pattern of numbness follows the median nerve distribution, because a number between 1 and 5 carries no map of the hand. Nor can it distinguish a nerve compressed at the wrist from one irritated further up the arm or in the neck. Those are questions for a history, an examination and, when the picture is unclear, nerve testing — the territory the orthopaedic guideline covers alongside its treatment recommendations 3Ref 3American Academy of Orthopaedic Surgeons (AAOS) (2016).Management of Carpal Tunnel Syndrome — Evidence-Based Clinical Practice Guideline.That an orthopaedic-society evidence-based guideline addresses both the diagnosis and the treatment of carpal tunnel syndrome, with splinting and corticosteroid injection among the nonsurgical recommendations and surgical release for appropriate patients..

There is a second absence worth naming. The defining paper reports no minimal clinically important difference and no minimal detectable change 1Ref 1Levine DW, Simmons BP, Koris MJ, et al. (1993).A self-administered questionnaire for the assessment of severity of symptoms and functional status in carpal tunnel syndrome.The Boston Carpal Tunnel Questionnaire's construction, structure, scoring and original psychometrics: a self-administered instrument with two independently scored scales, a Symptom Severity Scale and a Functional Status Scale, each item carrying five ordered responses and each scale scored as the mean of its items to give a 1-5 range in which 1 is the best outcome and 5 the worst; reproducibility of 0.91 and 0.93 and internal consistency of 0.89 and 0.91; validity established as positive but modest-to-weak correlations with conventional clinical and electrodiagnostic measures, with the authors concluding that the scales capture outcome dimensions not reflected by traditional clinical measurements; responsiveness in 38 post-operative patients reassessed at about 14 months, symptom severity moving 3.4 to 1.9 and functional status 3 to 2; and the absence in this paper of any MCID, MDC, diagnostic cutoff or severity band., so it does not say how large a shift in either number counts as real rather than as ordinary variation. Figures of that kind come from later research, and they vary by population and treatment.

What happened to the scores after surgery in the original study

The 1993 paper tested whether the scales respond to change, using 38 patients reassessed roughly fourteen months after an operation. Symptom severity scores fell from 3.4 to 1.9 and functional status scores from 3 to 2 1Ref 1Levine DW, Simmons BP, Koris MJ, et al. (1993).A self-administered questionnaire for the assessment of severity of symptoms and functional status in carpal tunnel syndrome.The Boston Carpal Tunnel Questionnaire's construction, structure, scoring and original psychometrics: a self-administered instrument with two independently scored scales, a Symptom Severity Scale and a Functional Status Scale, each item carrying five ordered responses and each scale scored as the mean of its items to give a 1-5 range in which 1 is the best outcome and 5 the worst; reproducibility of 0.91 and 0.93 and internal consistency of 0.89 and 0.91; validity established as positive but modest-to-weak correlations with conventional clinical and electrodiagnostic measures, with the authors concluding that the scales capture outcome dimensions not reflected by traditional clinical measurements; responsiveness in 38 post-operative patients reassessed at about 14 months, symptom severity moving 3.4 to 1.9 and functional status 3 to 2; and the absence in this paper of any MCID, MDC, diagnostic cutoff or severity band.. That is what responsiveness evidence looks like: it demonstrates that the instrument registers change when people change.

It is worth being precise about what that does not establish. Thirty-eight people is a small group. There was no comparison group left untreated, so the movement in the numbers cannot be separated from time, care and expectation. Everyone in it had surgery. The finding answers a question about the questionnaire, not a question about any individual hand.

A responsiveness study shows that the instrument detects change. It does not forecast what one person's hand will do.

This distinction matters more here than it might elsewhere, because these particular numbers are easy to read as a promise. They are a property of a measuring tool. The same two numbers, recorded before an operation and again afterwards, are what make carpal tunnel release recovery legible rather than remembered — which is a real and modest use, and the one the form was designed for.

Where the two numbers fit in a treatment conversation

Alongside everything else, and beneath most of it. The orthopaedic evidence-based guideline for this condition addresses both diagnosis and treatment, with splinting and corticosteroid injection among the nonsurgical options and surgical release for appropriate patients 3Ref 3American Academy of Orthopaedic Surgeons (AAOS) (2016).Management of Carpal Tunnel Syndrome — Evidence-Based Clinical Practice Guideline.That an orthopaedic-society evidence-based guideline addresses both the diagnosis and the treatment of carpal tunnel syndrome, with splinting and corticosteroid injection among the nonsurgical recommendations and surgical release for appropriate patients.. Patient-facing guidance from the same body describes the same shape: splinting and injections first, with release for cases that persist 2Ref 2American Academy of Orthopaedic Surgeons (OrthoInfo) (2024).Carpal Tunnel Syndrome.That carpal tunnel syndrome results from compression of the median nerve at the wrist, producing numbness, tingling and weakness, and that nonsurgical management includes splinting and injections with carpal tunnel release reserved for persistent cases..

A questionnaire score contributes a record to that conversation. It is not one of the carpal tunnel surgery indications, and no threshold on it triggers an operation. What it does supply is a consistent account of how the hand has behaved over weeks, which is exactly the thing that is hardest to reconstruct accurately in a ten-minute appointment.

The carpal tunnel release decision turns on the diagnosis, on what the nerve testing showed, on how the hand responded to splinting or injection, and on what the person needs their hand to do. A symptom score informs each of those and settles none of them.

The most common missed opportunity is simple: no baseline. A score recorded once, after treatment has already started, has nothing to be compared with. Two scores taken at the same clinic on the same form are worth more than any single number, however carefully it was collected.

A condition-specific form and a universal one

The Boston questionnaire asks about one condition, which makes it sensitive to that condition and unusable for anything else. The opposite approach also exists, and a person who has been through a hospital system in the last decade has probably met it. The PROMIS Physical Function item bank holds 124 calibrated items spanning upper-extremity, central and lower-extremity function together with instrumental activities of daily living 4Ref 4Rose M, Bjorner JB, Gandek B, Bruce B, Fries JF, Ware JE Jr. (2014).The PROMIS Physical Function item bank was calibrated to a standardized metric and shown to improve measurement efficiency.That the PROMIS Physical Function item bank comprises 124 calibrated items spanning upper-extremity, central and lower-extremity function plus instrumental activities of daily living; that its scores are reported on a standardized metric normed to a mean of 50 and standard deviation of 10 in a US general population sample with higher scores indicating better physical function; that a simulated ten-item computer-adaptive version eliminated floor effects, reduced ceiling effects and achieved higher precision than comparable-length static tools while discriminating age and disease groups better than legacy instruments; and that the paper establishes no cutoffs or severity bands..

Its scores are not a raw total. They are reported on a standardized metric normed to a mean of 50 and a standard deviation of 10 in a United States general population sample, with higher scores indicating better physical function 4Ref 4Rose M, Bjorner JB, Gandek B, Bruce B, Fries JF, Ware JE Jr. (2014).The PROMIS Physical Function item bank was calibrated to a standardized metric and shown to improve measurement efficiency.That the PROMIS Physical Function item bank comprises 124 calibrated items spanning upper-extremity, central and lower-extremity function plus instrumental activities of daily living; that its scores are reported on a standardized metric normed to a mean of 50 and standard deviation of 10 in a US general population sample with higher scores indicating better physical function; that a simulated ten-item computer-adaptive version eliminated floor effects, reduced ceiling effects and achieved higher precision than comparable-length static tools while discriminating age and disease groups better than legacy instruments; and that the paper establishes no cutoffs or severity bands. — the reverse of the Boston direction. A simulated ten-item adaptive version of that bank eliminated floor effects, reduced ceiling effects and achieved higher precision than any static tool of comparable length, discriminating between age and disease groups better than the older instruments it was tested against 4Ref 4Rose M, Bjorner JB, Gandek B, Bruce B, Fries JF, Ware JE Jr. (2014).The PROMIS Physical Function item bank was calibrated to a standardized metric and shown to improve measurement efficiency.That the PROMIS Physical Function item bank comprises 124 calibrated items spanning upper-extremity, central and lower-extremity function plus instrumental activities of daily living; that its scores are reported on a standardized metric normed to a mean of 50 and standard deviation of 10 in a US general population sample with higher scores indicating better physical function; that a simulated ten-item computer-adaptive version eliminated floor effects, reduced ceiling effects and achieved higher precision than comparable-length static tools while discriminating age and disease groups better than legacy instruments; and that the paper establishes no cutoffs or severity bands..

The trade is straightforward. A universal measure places someone against the general population and lets a hand clinic's numbers sit beside a knee clinic's. A condition-specific measure asks about the thing that is actually wrong. Neither converts into the other, and PROMIS carries no cutoffs or severity bands either 4Ref 4Rose M, Bjorner JB, Gandek B, Bruce B, Fries JF, Ware JE Jr. (2014).The PROMIS Physical Function item bank was calibrated to a standardized metric and shown to improve measurement efficiency.That the PROMIS Physical Function item bank comprises 124 calibrated items spanning upper-extremity, central and lower-extremity function plus instrumental activities of daily living; that its scores are reported on a standardized metric normed to a mean of 50 and standard deviation of 10 in a US general population sample with higher scores indicating better physical function; that a simulated ten-item computer-adaptive version eliminated floor effects, reduced ceiling effects and achieved higher precision than comparable-length static tools while discriminating age and disease groups better than legacy instruments; and that the paper establishes no cutoffs or severity bands.. Both are records rather than verdicts.