Study design: A prospective, criterion-based validity study.
Objectives: To assess the diagnostic properties of the carpal compression test (CCT) when performed with the Durkan carpal tunnel syndrome (CTS) gauge, and to determine the measurement validity of the gauge.
Background: The CCT has been reported to be highly sensitive (.87-.89) and specific (.93-1.0) in the diagnosis of CTS when it is done with thumb pressure. The accuracy of measurements with the Durkan CTS gauge, however, has not been established and the diagnostic sensitivity and specificity of the CCT when the gauge is used has not been independently confirmed.
Methods and measures: The study sample included 33 women and 19 men, aged 18 to 85 years (45.7 +/- 13.5 years). The accuracy of the gauge was determined with a force dynamometer and holding frame. Standard nerve conduction studies (NCS) and the CCT were performed on the symptomatic extremity of all subjects. A compatible history and the NCS results were used to confirm CTS.
Results: The Durkan gauge registered pressures of 11.94 psi and 15.25 psi at the 12 and 15 psi gauge marks, respectively. Test sensitivity and specificity were .36 (95% CI = .17-.54) and .57 (95% CI = .39-.74), respectively.
Conclusions: Pressure measurements obtained with the Durkan CTS gauge were accurate. The CCT when performed with the Durkan gauge, however, was neither sensitive or specific for the diagnosis of CTS.