Rasch analysis of the Rivermead Mobility Index: a study using mobility measures of first- XXXX inpatients.

@entity1 @entity64
OBJECTIVE: To evaluate the validity and item unidimensionality of the Rivermead Mobility Index (RMI) by using Rasch analysis. DESIGN: Application of Rasch analysis on the RMI partial data set. SETTING: A @entity64 program at a rehabilitation hospital in Italy. @entity1 : A total of 308 consecutive @entity1 (155 @entity1 , 153 @entity1 ; avg age, 62.79+/-11.94 y) hospitalized between 1990 and 1996. Average interval between @entity64 onset and admission was 52.48+/-36.22 days. INTERVENTION: Medical inpatient rehabilitation. MAIN OUTCOME MEASURES: @entity1 ' mobility status was assessed using the RMI administered at admission and discharge. Ratings were assigned by 4 staff members working as a team. We performed separate Rasch analyses on the RMI data, gathered from different groups of first @entity64 inpatients examined before and after rehabilitation treatment. RESULTS: asch analysis showed the overall good validity of the RMI, except for item 15, which did not fit the unidimensional continuum estimated through the Rasch rating model. CONCLUSION: The RMI is a unidimensional scale with a hierarchy of easy-to-hard test questions. Item difficulty level was stable when processed on different groups of @entity1 assessed on different occasions.
