title: Rasch analysis of the Rivermead Mobility Index: a study using mobility measures of first-stroke inpatients.
abstract: 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.
authors.affiliation: IRCCS-Fondazione Santa Lucia and Department of Psychology, University of Rome La Sapienza, Rome, Italy. gabriella.antonucci@uniroma1.it
authors.forename: Gabriella
authors.initials: G
authors.lastname: Antonucci
authors.forename: Teresa
authors.initials: T
authors.lastname: Aprile
authors.forename: Stefano
authors.initials: S
authors.lastname: Paolucci
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D000071939:Stroke Rehabilitation