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Leenesh Khadilkar, BPTh, MSc. Candidate (Health and Rehabilitation Sciences - Physical Therapy Field),
University of Western Ontario, London, Canada.
Validity of the Quick DASH in Patients undergoing Total Shoulder Arthroplasty
Khadilkar LC, Macdermid JC, Brimingham TB, Athwal GS
Study Design: Validity Study
Objective:: To examine the validity of the Quick DASH in patients undergoing total shoulder arthroplasty and to compare it to the full length DASH.
Summary and Background: Shoulder diseases are the third most common musculoskeletal disorders. The prevalence of shoulder pain increases with age and accounts for 26% in geriatric population. The DASH outcome measure is most commonly used for measuring upper extremity disabilities. The DASH outcome measure is associated with high Cronbach alpha (r = 0.97) which indicates item redundancy. Hence, a shorter version of DASH, the Quick DASH, was created. Limited studies have been completed examining the validity of the Quick DASH in assessing shoulder disorders. The few studies available have reported conflicting results.
Method and Materials: Patients undergoing total shoulder arthroplasty (N = 132) were assessed at baseline and at 3 and 6 months intervals after surgery. The patients completed the DASH, American Shoulder and Elbow Surgeon self report section (ASES), Short Form - 12 (SF-12) and underwent physical assessments consisting of range of motion (ROM) and isometric strength testing. The content validity of the full length and Quick DASH was assessed by performing ranked item analysis to assess the distribution of difficulty. The correlation of the impairment and disability measures were used to assess criterion, convergent and construct validity. Altman and Bland analysis detailed differences in the standard and Quick DASH scores across the scale range. Known group validity compared scores on subgroups based upon ability to work. Responsiveness was assessed by calculating a standardised response mean.
Results: The Quick DASH items were spread evenly throughout the levels of difficulties on the full length DASH, item most difficult to perform were higher level recreational activities (4.40 ± 0.98 to 3.47 ± 1.44). The Quick DASH correlation was excellent with the DASH (r = 0.94 to 0.98), moderate to good with ASES (r = 0.55 to 0.85) and low to moderate with impairment measures (ROM - r = 0.24 to 0.45, Isometric strength r = 0.15 to 0.49). Correlations with impairment and disability measures were similar across DASH versions. The Quick DASH was able to discriminate patients based on ability to perform routine work (49.63 vs. 61.51; p<0.011 at baseline, 27.25 vs. 46.52; p<0.00 at 3 months, 24.34 vs. 46.77; p<0.00 at 6 months). The Quick DASH and DASH showed similar responsiveness (SRM = 0.84 vs. 0.82 after 3 months and 1.06 vs. 1.07 after 6 months). Altman and Bland Analysis indicated small version differences (mean of 1.28, 2sd of 11.72 at baseline, mean of 1.29, 2sd of 8.96 at 3 months, mean of 0.98, 2sd of 8.88 at 6 months).