Discriminative validity and test-retest reliability of the Dellon-modified Moberg pick-up test in carpal tunnel syndrome patients

There is a scarcity of validated hand performance tests with proven reliability for quantifying functional deficits in patients with carpal tunnel syndrome (CTS). The Dellon-modified Moberg pick-up test (DMMPUT), composed of commonly used daily objects, is potentially well suited for that purpose. This study was designed to evaluate the test-retest reliability and discriminative validity of the DMMPUT in CTS patients. We compared 162 CTS patients with 116 age-matched controls. CTS severity was determined based on electrophysiological parameters and Levine's Self-Assessment Questionnaire. The mean time to complete each subset of the DMMPUT by the CTS patients was compared with that by the healthy subjects. Test-retest reliability was examined in 46 CTS patients. Discriminative validity was demonstrated through a significant difference in test completion time between the CTS subjects and their age-matched controls. With few exceptions, the test scores declined with increasing severity of electrophysiological abnormalities and subjective symptom severity. Test-retest reliability of the DMMPUT was high with an intra-class correlation coefficient of 0.91. The DMMPUT has discriminative validity and high test-retest reliability in patients with CTS. It can be a useful standardized outcome measure to gauge disease severity.