Measuring outcome

When evaluating the overall success of treatment from the patient’s point of view we usually ask them to rate the outcome on the following scale, which has been chosen so that most patients will agree on what the divisions mean:

- Worse - The hand is more of a problem after treatment than it was before - whether or not the symptoms have changed in character

- Unchanged - Symptoms after treatment are about as much of a nuisance as they were beforehand

- Slightly better - There has been an improvement, but there are still symptoms which are a significant nuisance and which the patient would prefer to be without given the choice. This grade implies that one would seek treatment for this if it was available.

- Much better - The hand is satisfactory to the extent that no further treatment would be sought even if available, but the patient can still detect that it is not quite as it was before the development of CTS.- 

- Complete cure - the hand has returned to exactly the state it was in before it ever had CTS with the exception (in the case of surgical treatment) of the presence of a visible scar which is unavoidable. In all other respects, a hand graded like this is ‘as good as new’.

If you are creating your own record of your CTS in this site and there is space to record an overall opinion on the effect of your treatment you should use this scale where possible.

A more formal way of measuring the subjective severity of CTS is to use a questionnaire in which the patient is asked to rate the severity of a selection of symptoms and the answers are then turned into a numerical score. Several symptom questionnaires have been used in studies of CTS, some of them designed specifically for CTS symptoms and others which were originally devised as more general measures of upper limb function. The most widely used of these tools for CTS is a questionnaire published by Levine et al in 1993. This has been shown to be a good indicator of the subjective severity of CTS symptoms and to be responsive to changes as a result of treatment. It is this questionnaire which is incorporated into this website as a part of our larger symptom survey. Thus, if you complete the CTS questionnaire on this site you will not only get an indicator of the probability that you have CTS but also the subjective severity scores derived from Dr Levine's questionnaires. This severity questionnaire does not have a universally accepted name but is variously referred to as the 'Boston' or 'Levine' questionnaire, the CTS severity instrument or as the CTS SSS and FSS - SSS standing for symptom severity scale and FSS for functional severity scale. The SSS and FSS are two subscale scores, the SSS indicating how bad the symptoms feel to the patient and the FSS indicating how much interference the symptoms cause with activities of daily living. The original publication was a little vague about exactly how the questionnaire should be answered by patients who had symptoms of differing severity in their right and left hands and various approaches to this have been adopted by other investigators who have used it. So far as I am aware the Boston group themselves now ask patients to answer the SSS questions separately for each hand but the FSS questions just once for both hands together. The approach adopted here is to ask for a complete set of answers for each hand - further details are shown on the relevant questionnaire pages. Once you have completed the entire symptom questionnaire on this site once you can complete the SSS and FSS repeatedly without doing the rest of the questionnaire in order to track changes in your symptoms over time.

Dr Atroshi has just published a revised version of the Levine/Boston instrument designed to tackle some of the oddities and redundancies in the original questionnaire (Atroshi 2011), but it remains to be seen whether this will be widely adopted. For the present we are continuing to use the original version in the interests of compatibility with all our existing data.

Many studies of treatment for CTS include outcome measures which are less dependent on reporting by the patient - change in measured grip strenth, two point discrimination, and change in nerve conduction study measurements are all popular though none of them correlate very well with subjective success or failure. There is starting to be some early data on how ultrasound imaging of the nerve changes with treatment, at least with surgery. In the case of both ultrasound and nerve conduction studies it appears that many patients continue to show residual abnormalities after surgery even when symptoms and signs have entirely resolved.

Revision date - 4th October 2011

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