Rasch analysis of the Rivermead Mobility Index: a study using mobility measures of first-stroke inpatients.
OBJECTIVE
To evaluate the validity and item unidimensionality of the Rivermead Mobility Index (RMI) by using Rasch analysis.


METHODS
Application of Rasch analysis on the RMI partial data set.


METHODS
A stroke program at a rehabilitation hospital in Italy.


METHODS
A total of 308 consecutive patients (155 women, 153 men; avg age, 62.79+/-11.94 y) hospitalized between 1990 and 1996. Average interval between stroke onset and admission was 52.48+/-36.22 days.


METHODS
Medical inpatient rehabilitation.


METHODS
Patients' 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 stroke 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.


CONCLUSIONS
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 patients assessed on different occasions.
Antonucci
Gabriella
G
IRCCS-Fondazione Santa Lucia and Department of Psychology, University of Rome La Sapienza, Rome, Italy. gabriella.antonucci@uniroma1.it
Aprile
Teresa
T
Paolucci
Stefano
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D000071939:Stroke Rehabilitation