AIM: To determine the relationship between the Assisting Hand Assessment (AHA), valid for children aged 18 months to 18 years with unilateral cerebral palsy (CP), and the Mini-Assisting Hand Assessment (Mini-AHA), valid for children aged 8 months to 18 months, so results from the two tests can be compared.
METHOD: This psychometric study used AHA data from 157 children and Mini-AHA data from 86 children. In addition, data from children who had undertaken both the AHA and Mini-AHA assessments within a fixed time frame were sought. A Rasch measurement model analysis was conducted using a concurrent test linking technique when both tests have been undertaken by the same (common) persons.
RESULTS: Data from 23 children who completed both assessments were added to previous AHA and Mini-AHA data. Using the combined data, the common person test linking Rasch analysis showed the AHA and Mini-AHA test results were not equivalent and a conversion table of Mini-AHA units to AHA units was needed.
INTERPRETATION: Information from the conversion table will allow clinicians and researchers to measure changes in use of the affected hand during bimanual performance in children with unilateral CP from 8 months to 18 years.