Construct validity of the quality of upper extremity skills test for children with cerebral palsy

Aim: To investigate Quality of Upper Extremity Skills Test (QUEST) construct validity for children with cerebral palsy (CP). Method: 170 QUEST assessments from a convenience sample of 94 children with CP involved in clinical and research treatment programs (2 to 16 years; 54 male, 40 female; mean age 6 years 10 months, SD 2 years 11 months; GMFCS I-V). Results: The QUEST was not unidimensional; many items demonstrated poor fit when total scores were analyzed; goodness of fit improved when domains were considered independently and limbs separately examined. QUEST items involving elbow flexion and/or forearm in pronation were easily achieved thus reducing test sensitivity. Postures items in the grasp domain behaved erratically with little total score relationship. Implications: Calculating total scores is discouraged. Reporting QUEST results separately for domains and each limb is recommended. Posture items in the grasp domain had little relationship with total score and it is recommended that they be removed from the test.