Determining the sensitivity and specificity of common diagnostic tests for carpal tunnel syndrome using latent class analysis.
BACKGROUND
The accuracy of a diagnostic test used to classify a patient as having disease or being disease-free is a valuable piece of information to be used by the physician when making treatment decisions. If a standard reference test is available, determining the sensitivity and specificity of a new test is straightforward. However, if that reference test is incorrectly assumed to be perfectly sensitive and specific, the errors of the reference test can result in an underestimation of the accuracy of the test being evaluated. Latent class analysis can be applied to determine the sensitivity and specificity of a new test when no standard exists.


METHODS
Latent class analysis was used to determine the accuracy rates of three commonly used measures of carpal tunnel syndrome: Tinel's sign, Phalen's test, and the nerve conduction velocity test. Data included 162 wrists from 81 patients seeking treatment for symptoms associated with carpal tunnel syndrome.


RESULTS
Tinel's sign and Phalen's test were both highly sensitive (0.97 and 0.92, respectively) and specific (0.91 and 0.88, respectively). The sensitivity and specificity of the nerve conduction velocity test were 0.93 and 0.87, respectively.


CONCLUSIONS
Estimates of the sensitivity and specificity of these common tests for carpal tunnel syndrome support their widespread clinical use.
LaJoie
A Scott
AS
Department of Psychological and Brain Sciences, University of Louisville, School of Public Health and Information Sciences, Louisville, KY 40202, USA. lajoie@louisville.edu
McCabe
Steven J
SJ
Thomas
Binu
B
Edgell
Stephen E
SE
D000328:Adult; D000368:Aged; D002349:Carpal Tunnel Syndrome / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction; D011336:Probability; D012189:Retrospective Studies; D012680:Sensitivity and Specificity