The Consistency and Construct Validity of Wolf Motor Function Test With Functional Variables and SF-36 Questionnaire in Iranian Stroke Patients

Background: One of the most important indicators for assessing the validity of a scale is the determination of the construct validity of that scale. Since no standard gold test exists to measure the upper limb function in patients with stroke, the study of the construct validity of the Wolf Motor Function Test (WMFT) is of particular importance. Objectives: To evaluate the construct validity of the scores of the Persian version of the WMFT with functional variables, as well as to verify its convergence validity with the physical component summary of the SF-36 Health Survey, and its discriminant validity with the mental component summary of SF-36 Health Survey. Materials & Methods: The tests were conducted on 56 patients with stroke, and the scores were calculated. By using this data, the construct validity of the Wolf scale and the convergence and discriminant validity of the scores derived from the Persian version of WMFT, and the physical and mental component summary of the SF-36 Health Survey were obtained. Results: There was no significant correlation between the age and duration of the stroke in patients, and the total functional score and the median time of performing the tasks of the Persian version of WMFT (P>0.05). No significant difference was seen between the sexes in terms of the total score of performing tasks, but the median time of performing the tasks was significantly different between men and women (P=0.04). There was a moderate statistical correlation between the scores of the Persian version of WMFT and the physical component summary (r=0.60, P<0.001 and r²=0.74), and the mental component summary of SF-36 Health Survey (r=0.60, P<0.001 and r²=0.82). Conclusion: The Persian version of WMFT has acceptable construct validity with functional variables and the overall score of the SF-36 questionnaire.