SELF-ADMINISTERED OUTCOME INSTRUMENT IN CARPAL-TUNNEL SYNDROME - RELIABILITY, VALIDITY AND RESPONSIVENESS EVALUATED IN 102 PATIENTS

We evaluated a Swedish version of a self-administered disease-specific outcome questionnaire for carpal tunnel syndrome regarding reliabilit y, validity and responsiveness to clinical change. It consists of mult i-item scales assessing symptom severity, function, patient satisfacti on and quality of life. It was given to 102 patients before and 3 mont hs after carpal tunnel release. Test-retest reliability, studied in a subsample of 22 patients on two occasions with a 1-3-week interval, sh owed good agreement between the scores. Internal consistency of the sc ales was high (Cronbach alpha 0.80-0.95). Validity of the scales was e valuated using the SF-36 general health questionnaire in a subgroup of 48 patients as well as items concerning patient satisfaction, showing the expected relationships between these measures. Responsiveness of the scales to clinical change, estimated by the effect size and standa rdized response mean, was large (0.94-1.7). We conclude that this ques tionnaire can provide a standardized measure of symptom severity and f unctional status, as well as patient satisfaction and quality of life in the carpal tunnel syndrome.