Measurement Properties of Streamlined Wolf Motor Function Test in Patients at Subacute to Chronic Stages After Stroke

Background. Previous research using the streamlined Wolf Motor Function Test (SWMFT) has focused either on the 3- to 9-month period or on the >12-month period after stroke and lacked the information for those at 9 to 12 months. Whether SWMFT scores reflect motor deficit and recovery from early to late stages after stroke remains unclear. Objective. A retrospective study using the Functional Ability Scale (FAS) was conducted to evaluate whether all SWMFTs items measure the poststroke recovery of upper extremity (UE) motor function and if they could be used for patients within 9 to 12 months after a stroke. Methods. Rasch analysis was conducted, and data were drawn from patients 3 months to years after a stroke. Results. The continuum of UE motor function in SWMFT-FAS was supported. Subacute patients had the best motor function, followed by the 9- to 12-month group, and then chronic patients. Variation in UE motor function was large (2.35-2.72 logits), and motor abilities of these 3 groups overlapped. The 8 SWMFT items could target a broad range of UE motor function, from -8.28 to 7.80 logits. The average difficulty of these 8 items also matched the UE motor ability of the subgroup at 9 to 12 months after stroke, and individual versions of the SWMFT performed well to assess the motor ability of this group. Conclusions. The SWMFTs had sound hierarchical properties. The SWMFT-Chronic or the SWMFT-Subacute could be used to evaluate UE function of this subgroup at 9 to 12 months after stroke.