Convergent Validity of Thoracic Outlet Syndrome Index (TOSI)

Abstract

<p>No disease-specific evaluation score for thoracic outlet syndrome (TOS) patients was available prior to the presentation of the Thoracic Outlet Syndrome Index (TOSI) score. Our aim was to assess the convergent validity of the TOSI when compared with the short form of Disabilities of the Arm, Shoulder and Hand (QDASH), the Cervical Brachial Symptom Questionnaire (CBSQ), and pain numeric rating scale (painNRS) after supraclavicular rib-sparing decompression for neurogenic TOS. The TOSI takes into account five domains important to TOS patients with 15 questions, whereas QDASH considers only four domains, and CBSQ and painNRS each has only one domain. Our 67 TOS patients, mean age 36.5 years at surgery, were evaluated clinically for a mean 13.2 years after rib-sparing surgery. They completed the QDASH, the CBSQ, the pain NRS, and the TOSI questionnaires. Correlations between TOSI total score and QDASH, CBSQ total scores, and the painNRS were strong: 0.67 for TOSI vs. QDASH; 0.75 for TOSI vs. CBSQ; and 0.65 for TOSI vs. painNRS. The TOSI demonstrated good convergent validity. It may thus become a valuable addition among tools for assessing the quality of life and functioning of those with neurogenic thoracic outlet syndrome as well as for improving comparability of results across varying settings in this field.<br></p>