The minimal important change for the seven-item disability of the arm, shoulder, and hand (DASH 7) questionnaire – Assessing shoulder function in patients with subacromial pain

BACKGROUND: The DASH 7 is a recently published activity-related 7-item short form of the disability of the arm, shoulder, and hand (DASH) questionnaire developed to assess shoulder function in patients with subacromial pain. Before implementation in both intervention studies and in clinical practice, it is essential to evaluate its responsiveness. The objective of this study was to determine the minimal important change (MIC) in the DASH 7 questionnaire for patients with subacromial pain after a 3 months exercise intervention in a primary care context. METHODS: In this psychometric study the anchor-based MIC-distribution method was used to establish the MIC. The Patient Global Impression of Change (PGIC) was used as external criterion. Data from a clinical implementation study, aimed to implement a specific exercise strategy for patients with subacromial pain among physiotherapists in primary care, were used. Data from 70 patients were included in the analyses. RESULTS: The correlation coefficient between Patient Global Impression of Change and the DASH 7 score change was 0.67 and the area under the curve was 0.94 (95% confidence interval: 0.88-1.0). The MIC(ROC) 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 MIC(95% limit) for improvement was detected at a mean change of 25.7 points. There were 77% of the patients who reached at least this MIC(ROC) and 51% who reached at least the MIC(95% limit) after 3 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.