The structure of functional and community outcomes following traumatic brain injury.

OBJECTIVES: To investigate the dimensionality of functional and community outcomes following serious TBI. To identify items that fit, misfit or are redundant, as well as to assess person misfit. METHODS: Rating-scale (Rasch) analysis was applied to 1-year follow-up data from 231 cases in the US National TBI Model Systems database. Items selected for analysis included all items indicative of global outcomes, disability, activity or participation. RESULTS: A powerful singular measurement dimension was identified. Item reliability was very high (0.98), as was person reliability (0.97). The dimension fit over 90% of cases; that is approximately 10% of cases displayed anomalous patterns of functioning that indicated that their functioning was not measurable in terms of the general dimension identified. There was tension within the dimension between ratings of dependency (FIM) and cognitive functioning in everyday life (NFI). Most-but not all-neuropsychological test scores misfit the outcome dimension. CONCLUSIONS: Actual dimensionality was distinct from the named scales employed. A unidimensional measure model fit the data much better than expected. This outcome dimension might be called 'general community functioning'. In the future, it should be possible to develop more valid and parsimonious measures of community outcomes following TBI.

Assessing functional status: exploring the relationship between the multiple sclerosis functional composite and driving.

OBJECTIVE: To explore the relationship between the Multiple Sclerosis Functional Composite (MSFC), which is comprised of 3 clinical dimensions (arm and hand function, leg function and ambulation, cognition), and an everyday functional skill, driving performance. DESIGN: Cohort study. SETTING: Medical rehabilitation research organization. PARTICIPANTS: Twenty-nine individuals with documented multiple sclerosis (MS) and limited motor decrements. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Driving-related skills were measured by using the overall category rating from the Useful Field of View (UFOV) Test, its 3 subtests, the error and latency scores from the Neurocognitive Driving Test (NDT), subjective (self-report) and objective (Department of Motor Vehicles [DMV] reports) reported driving experience, and number of motor vehicle crashes. Within the group, differences were explored between participants rated as low risk versus moderate-high risk on the UFOV overall score and between participants who reported a change in driving habits after MS versus those who reported no change. RESULTS: The overall MSFC score correlated significantly with the UFOV overall score, the visual-information processing and selective attention subtests of the UFOV, the NDT latency score, as well as with the number of days a week the individual drove and the number of crashes reported by the DMV. An examination of the MSFC components revealed that the cognition component was significantly related to the UFOV overall score, all 3 subtests of the UFOV, and the NDT latency score. The arm and hand function component correlated significantly with NDT latency and the selective attention subtest of the UFOV. Individuals classified as low risk on the UFOV overall had more education, better MSFC scores, and lower NDT latency scores. Only the overall MSFC score distinguished those who reported a change in driving habits after onset of MS. CONCLUSIONS: Problems with everyday functional skills such as driving are accurately identified through the use of the overall MSFC and its components.

Scaling of the revised Oswestry low back pain questionnaire.

OBJECTIVE: To evaluate the measurement properties of the Revised Oswestry Disability Questionnaire (RODQ) by using rating scale analyses. DESIGN: Calibration of item responses by using a data set. SETTING: Four outpatient therapy clinics in the northeastern United States. PATIENTS: Convenience sample of 95 community-dwelling adults exhibiting mild to severe low back pain-related disability (LBP-D). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: The RODQ. RESULTS: Several Rasch analyses were performed, with 1 item deleted and 2 response categories collapsed, creating a better test without increased error. A schema for item administration and evaluation was also developed. CONCLUSIONS: By using the abbreviated scale, suggested item order, and predicted responses, abbreviated versions of the instrument can be applied to measure LBP-D more efficiently.