Occupation-based evaluation and intervention : validity of the assessment of motor and process skills when used with persons with mental retardation

Sammanfattning: The ability to perform everyday life occupations is a critical component in both evaluation and intervention for persons with mental retardation (MR). While the ability to perform personal and instrumental activities of daily living (ADL) has always been important for occupational therapy (OT) practice, there is an absence in OT literature and research with a focus on ADL and persons with MR. The overall aim of this thesis was to evaluate the validity of the Assessment of Motor and Process Skills (AMPS) for evaluation and intervention of ADL ability for persons with MR.In order to evaluate the evidence of validity of the AMPS ability measures based on relation to level of MR, two groups of participants with MR were evaluated with the AMPS (,#=22; #= 39). The results indicated expected moderate relationships between ADL motor and ADL process ability measures and level of MR, despite different methods used for evaluating level of MR. The results also indicated that the results of the AMPS evaluation could be used to directly describe and measure the consequences in performance of ADL tasks for persons with different levels of MR.The evidence of validity of the AMPS was further examined in a study including participants with different types of developmental disabilities (e.g., MR, cerebral palsy, spina bifida) (#=1724). An application of many-faceted Rasch analysis was used to examine goodness-of-fit of the responses for the tasks, skill items, and participants included in the study. All tasks and all items except one demonstrated acceptable goodness-of-fit to the model on the ADL motor and ADL process scales. An expected proportion of participants demonstrated acceptable goodness-of-fit on the ADL motor scale. On the ADL process scale, a slightly lower proportion of participants than expected demonstrated acceptable goodness-of-fit. The results indicated further that persons with more severe levels of MR and persons with more limited ADL process abilities demonstrated different response patterns across tasks and possibly items.The evidence of validity of the internal structure of the AMPS scales was also evaluated between persons with mild and moderate MR (#=178; #=170). Group specific ADL motor and ADL process skill item hierarchies were generated using many-faceted Rasch analyses and compared. The hierarchies of ADL motor and ADL process skill items remained stable across groups, indicating evidence of validity of the AMPS scales when used to evaluate persons with MR. The results also indicated that although participants with moderate MR demonstrated overall lower mean ADL motor and ADL process ability, they did perform some specific ADL motor and ADL process skills at a similar level as persons with mild MR.Finally, the utility of the AMPS ability measures for detecting change were examined in an intervention study including three female participants with moderate MR. The study was based on a single case design and evaluated the effectiveness of a structured occupational therapy intervention program. Improvements were found for the participants in relation to the implementation of the program, but the pattern of changes were different between the participants and across the dependent variables. ADL process ability was the only variable that improved across all participants. The results supported the ADL process abilities as sensitive measures for detecting changes in ADL ability of persons with MR.In conclusion, the results of these studies contribute to the evidence of validity of the AMPS ability measures and scales, specifically in relation to the evaluation of persons with MR. The finding that an OT program resulted in improved ADL process ability also suggest that the results of the AMPS can be used to plan as well as evaluate outcomes of OT practice. Further research is also suggested in order to improve validity evidence and utility of the AMPS when used with persons with MR.