The minimal important change for the DASH 7 questionnaire – assessing shoulder function in patients with subacromial pain

Abstract

Abstract Background The DASH 7 is a recently published activity related seven-item short form of the Disability of the arm, shoulder, and hand questionnaire (DASH) developed to measure shoulder function in patients with subacromial pain. Before implementation in both intervention studies and in clinical practice it is essential to evaluate its responsiveness. Objective: To determine the minimal important change (MIC) in the DASH 7 questionnaire for patients with subacromial pain after a three months exercise intervention in a primary care context. Design A psychometric study, using the anchor-based MIC-distribution method to establish the MIC. Setting and patients: Data from a clinical implementation study, aimed to implement a specific exercise strategy for patients with subacromial pain among physiotherapists in primary care, was used. Data from seventy patients was included in the analyses. Measure ments: The DASH 7 questionnaire, and as external criterion the Patient Global Impression of Change (PGIC) was used. Results The correlation coefficient between PGIC and the DASH 7 score change was 0.67 and the area under the curve (AUC) was 0.94 (95% CI: 0.88-1.0). The MICROC for improvement was detected at a mean change in 6.5 points with the sensitivity at 0.98 (98%) and the specificity at 0.78 (78%) and the MIC95% limit for improvement was detected at a mean change of 25.7 points. There were 77% of the patients that reached at least this MICROC and 51% who reached at least the MIC95% limit after three months of exercise intervention. Conclusion The DASH 7 is responsive to change over time and can discriminate between patients considered to be improved and patients considered not improved. These MIC-values for patients with subacromial pain in the primary care setting can be used in clinical practice and in intervention studies as an indication on the patients clinically important level of score change for improvement. Level of evidence Basic Science Study; Validation of Outcome Instruments