Construct validity and test-retest reliability of the revised Upper Extremity Work Demands (UEWD-R) Scale

Background: The revised Upper Extremity Work Demand (UEWD-R) Scale is a six-item self-report questionnaire to measure the workload of the upper limbs. UEWD-R consists of a force/posture scale and a repetition scale. Psychometric properties are unknown so far.

Purpose: Assess the construct validity and the testretest reliability of UEWD-R.

Method: Participants from different levels of physical work demands (based on the Dictionary of Occupational Titles (DOT) categories) were included. Construct validity was determined by testing 11 predefined hypotheses regarding UEWD-R related to other constructs, including a workplace observation using the Rapid Upper Limb Assessment (RULA). Correlations between these measures were calculated using Spearman correlation coefficients. Test-retest reliability was determined using the intraclass correlation coefficient (ICC) for agreement. The smallest detectable change (SDC) was calculated.

Results: Fifty-four participants participated (63% men, mean age 39.4 years). The four DOT categories were equally represented. Nine out of 11 predefined correlations were confirmed (82%), indicating good construct validity. Strong expected correlations of UEWDR-total versus RULA-C (r=0.69) and UEWD-R-repetition versus RULA-muscle (r=0.12) were not confirmed. The test-retest reliability was good (ICC agreement=0.79). The SDC was 4.85.

Conclusion: Construct validity and the test-retest reliability of UEWD-R were good. UEWD-R can be used to evaluate the workload of the upper extremities. However, further research is advised to assess the validity of the UEWD-R not only by testing associations with RULA, but also with other observational measures.