Evaluation of the DASH Questionnaire Factor Structure in Patients with Nerve Injury
Christine B Novak, PT, PhD1; Susan E. Mackinnon, MD2; Dimitri J Anastakis, MD1; Steven J. McCabe, MD1
1University of Toronto, Toronto, ON, Canada, 2Washington University School of Medicine, St. Louis, MO
Introduction: Standardized questionnaires are often used to evaluate upper extremity disability as a single construct and the Disabilities of the Arm, Shoulder and Hand (DASH) is one of the most widely used questionnaires. The purpose of this study was to evaluate the validity of the factor structure of the DASH questionnaire in patients with upper extremity nerve injury.
Materials & Methods: Data for this study included patients with an upper extremity nerve injury from a previous cross-sectional study. Institutional Research Board approval was obtained for secondary data analyses. Descriptive, factor analyses and ANOVA were performed.
Results: This study included 242 patients with upper extremity nerve injury; distal nerve (n = 131), brachial plexus (n = 88), single proximal nerve (n = 23). The mean DASH score was 47.3 ± 22. The internal consistency was high for the DASH (? = 0.96). A 3-factor structure had the highest variance (60.7%) and no overlap between factors. The 3-factor structure revealed domains related to: 1) light effort & dexterity tasks; 2) greater effort tasks; and 3) limitations in work/social activities & pain. There were significant differences in the overall DASH (p < 0.001) and factor (p < 0.03) scores between injured nerve groups (Figure 1). Brachial plexus injuries had significantly higher overall DASH scores compared to distal and single proximal nerve injuries. Light Effort & Dexterity Tasks factor scores were significantly lower in single proximal nerve injuries compared to brachial plexus and distal nerve injuries. With non-dominant hand compared to dominant hand involvement, there was no difference in overall DASH scores. However in the Light Effort & Dexterity Tasks factor there were significantly higher DASH scores with dominant hand involvement (p = 0.001).
Conclusions: In this sample of patients with nerve injury, the confirmatory factor analysis of the DASH questionnaire indicated a multi-factor construct related to light effort & dexterity tasks, greater effort tasks, and limitations in work/social activities & pain. These domains should be considered when utilizing the DASH questionnaire. The factor scores may be helpful in identifying levels of disability related to specific tasks in different nerve injuries and with dominant hand involvement.
Figure 1: Comparison of DASH & Factor Scores for Nerve Injured Groups
Back to 2019 Abstracts