Development of a computerized adaptive testing system of the Fugl-Meyer motor scale in stroke patients

Objective: To develop a computerized adaptive testing system of the Fugl-Meyer motor scale (CAT-FM) to efficiently and reliably assess motor function in patients with stroke. Design: First, a simulation study was used to develop and examine the psychometric properties of the CAT-FM. Second, a field study was employed to determine the administration efficiency of the CAT-FM. Setting: One medical center and 1 teaching hospital. Participants: Patients' responses (n=301) were used for the simulation study; 49 patients participated in the field study. Interventions: Not applicable. Main Outcome Measures: The 2 CAT-FM item banks (upper extremity and lower extremity) include 37 items from the original Fugl-Meyer scale. The reliability, validity, and responsiveness of the CAT-FM were determined by the simulation study. Results: Two stopping rules (reliability <0.9 or an increase of reliability <.01 after testing an item) were used. The simulation study showed that the CAT-FM had high reliability (<.93 for upper-extremity and lower-extremity subscales) and concurrent validity (Pearson r<.91 for the upper-extremity and lower-extremity subscales and motor scale). The responsiveness was moderate (standardized response mean for the upper extremity=.67, lower extremity=.79, and motor=.77) for the 226 patients who completed both assessments at 14 and 90 days after stroke. The field study found that, on average, the time needed to administer the CAT-FM was 242 seconds with 4.7 items. Conclusions: The CAT-FM is an efficient, reliable, valid, and responsive clinical tool for assessing motor function in patients with stroke.