Assessment of construct validity of the Finnish versions of the Disabilities of Arm, Shoulder and Hand Instrument and the Michigan Hand Outcomes Questionnaire.

ABSTRACT

STUDY DESIGN: Cross-sectional study. INTRODUCTION: There is a lack of information on the measurement properties of patient-reported upper extremity instruments and their association to health-related quality of life (HRQoL). PURPOSE OF THE STUDY This study aimed to examine and compare the measurement properties and construct validity of the Disabilities of Arm, Shoulder, and Hand (DASH) Instrument and the Michigan Hand Questionnaire (MHQ) using a heterogeneous sample of patients with hand and wrist problems. METHODS: Two hundred fifty consecutive patients visiting a general orthopedic outpatient clinic due to various hand/wrist problems were invited to participate in the study. A total of 193 (77%) participants provided sufficient patient-reported outcome data and were included in the analysis. Participants completed the DASH, the MHQ, the EQ-5D-3L, and pain on a visual analog scale instruments. Grip and key pinch forces were measured. Scale targeting, relatedness of demographics, and construct validity of the DASH and the MHQ were assessed. RESULTS: Both the DASH and the MHQ had good targeting, but the DASH had wider coverage. The convergence between the DASH and the MHQ was high. The DASH was more closely related to HRQoL than the MHQ in terms of EQ-5D scores. DISCUSSION: The DASH instrument appeared to measure hand function and disability from a perspective of HRQoL superior to the MHQ among patients with heterogeneous hand and wrist complaints. CONCLUSION: The DASH performs well in measuring the HRQoL-related hand outcomes while the MHQ might be more specific for the affected hand.