Clinical diagnosis of carpal tunnel syndrome: a systematic review

The purposes of this systematic review were to examine the properties of clinical tests used in the diagnosis of carpal tunnel syndrome (CTS) and to provide estimates of their sensitivity and specificity. A literature search was conducted using two databases-PubMed and the Cumulative Index to Nursing and Allied Health Literature (CINAHL)-from 1986 to June 2003, and hand-searching reference lists of retrieved articles. Two reviewers evaluated the papers for quality using an evaluation tool developed by one of the authors. Estimates of sensitivity and specificity were determined by averaging values across studies weighted by sample size. Although 60 studies were reviewed in detail, many were of poor quality (mean quality score was 6.6 of 12, with only 15 of 60 obtaining a score of 8 or greater). The most frequently studied test was Phalen's, with an overall estimate of 68% sensitivity and 73% specificity. Next was Tinel's, with estimates of 50% and 77%, and then carpal compression, with estimates of 64% and 83% for sensitivity and specificity, respectively. Two-point discrimination and testing of atrophy or strength of the abductor pollicis brevis proved to be specific but not very sensitive. The estimates determined in this review should help therapists choose clinical tests with the appropriate balance of sensitivity and specificity required for diagnosing carpal tunnel syndrome in their specific clinical environments.