Rasch Analysis of the International Quality of Life Basic Data Set Version 2.0.

OBJECTIVE: To examine the internal construct validity of the International Spinal Cord Injury Quality of Life Basic Data Set Version 2.0 (QoL-BDS V2.0) and compare this with the internal construct validity of the original version of the QoL-BDS. DESIGN: International cross-sectional psychometric study. SETTING: Spinal rehabilitation units, clinics, and community. PARTICIPANTS: The study involved 5 sites and 4 countries, 2 of whose primary language is not English. Each site included a consecutive sample of inpatients with spinal cord injury or disease (SCI/D) and a convenience sample of individuals with SCI/D living in the community (N=565). MAIN OUTCOME MEASURES: The QoL-BDS V2.0 consists of the 3 original items on satisfaction with life as a whole, physical health, psychological health of the QoL-BDS, and an additional item on satisfaction with social life. All 4 items are answered on a 0-10 numeric rating scale. Rasch analysis was performed on versions 1.0 and 2.0 of the QoL-BDS to examine the ordering of the items' response options, item scaling, reliability, item fit, local item independence, differential item functioning, and unidimensionality. RESULTS: The sample included 565 participants with 57% outpatients and 43% inpatients. Mean age was 51.4 years; 71% were male; 65% had a traumatic injury, 40% had tetraplegia, and 67% were wheelchair users. Item thresholds were collapsed for ordering, and subsequent analyses showed good internal construct validity for the QoL-BDS V2.0 with a person separation reliability of 0.76 and Cronbach α of 0.81. Infit and outfit statistics ranged 0.62-0.91. No local dependencies and multidimensionality were found. Differential item functioning was observed only for country and inpatients vs outpatients but not for other participants' characteristics. Differences in internal construct validity between the 3-item and 4-item versions were minimal. CONCLUSIONS: The results of this Rasch analysis support the internal construct validity of the QoL-BDS V2.0.

Change in mobility independence over 5 years for persons with chronic spinal cord injury.

OBJECTIVES: To evaluate change in mobility independence (MI) in community dwelling persons with spinal cord injury (SCI). PARTICIPANTS: Community Survey. DESIGN: Cohort study. Rasch analysis was applied to the mobility subscale of the Spinal Cord Independence Measure - Self-Report data from years 2012 to 2017, resulting in a Rasch Mobility Independence Score (RMIS). We employed multilevel modeling to examine RMIS and its change over 5 years, adjusting for demographics and SCI severity; random forest regression was applied to determine the impact of modifiable factors (e.g. environmental factors, home-support) on its change. RESULTS: The analysis included 728 participants. The majority (≈85%) of participants demonstrated little or no change in RMIS from 2012 to 2017; however, a smaller proportion (15%) showed considerably large change of more than 10 on the 100-point scale. A mixed-effects model with random slopes and intercepts described the dataset very well (conditional R2 of 0.95) in terms of demographics and SCI severity. Age was the main predictor of change in RMIS. Considering SCI severity, change in RMIS was related to age for the subgroup with paraplegia, and to time since injury for the subgroup with tetraplegia. No impact of modifiable factors was found. CONCLUSION: RMIS in persons with SCI changes over a period of 5 years, especially in elder patients with paraplegia and persons with incomplete tetraplegia with more than 15 years of time since injury. During routine follow-up change in mobility independence should be assessed in order to timely intervene and prevent mobility loss and participation limitations.

Change in environmental barriers experienced over a 5-year period by people living with spinal cord injury in Switzerland: a prospective cohort study.

STUDY DESIGN: Cohort study with two measurement occasions. OBJECTIVES: To investigate change in environmental barriers experienced by people living with spinal cord injury (SCI) over a 5-year period. SETTING: Community, Switzerland. METHODS: Data were from the Swiss spinal cord injury (SwiSCI) survey. Main outcome measure was the Nottwil Environmental Factors Inventory-Short Form. Random-effects Poisson regression featuring between-within estimation was used to examine predictors of the number of environmental barriers and of its change over time. RESULTS: One thousand five hundred and forty-nine persons participated in Survey 2012 and 1530 participated in Survey 2017; 761 participated in both surveys. In both surveys most participants reported at least three barriers. Leading issues were unfavorable climate, inaccessibility of buildings and public spaces, and lack of or insufficiently adapted means of transportation. Reporting of barriers related to climate, finances, and state services declined over time. Between subjects, having more health problems, lesser physical independence, poorer mental health, and a lower household income were related to a higher number of barriers experienced. Within subjects, improvements in income, physical independence, and mental health over time were related to a reduction in barriers. CONCLUSIONS: Inaccessibility of buildings and places and problems with transportation remained major barriers over a 5-year period and should be priorities of Swiss disability policy. People with reduced mental and physical health, and those with lower income are vulnerable groups deserving specific attention. Policies targeting income and life-long rehabilitation targeting health promotion and maintenance may be suitable means to reduce the experience of environmental barriers.

Factors associated with labor market participation of persons with traumatic SCI in Switzerland: analyzing the predictive power of social background, health, functional independence, and the environment.

STUDY DESIGN: Cross-sectional study using data from the 2012 community survey of the Swiss Spinal Cord Injury Cohort Study. OBJECTIVES: To identify associations between selected factors related to the social background, health, functional independence, and the environment of persons with spinal cord injury (SCI) and their labor market participation. SETTING: Community-based, Switzerland. METHODS: Labor market participation (i.e., involvement in paid work or not) was determined for a sample of 966 persons with traumatic SCI who were of employable age at the time of the survey. Applying an exploratory approach, potential predictors of labor market participation were selected based on the literature and using a bidirectional stepwise variable selection approach. Descriptive statistics were calculated and weighted bootstrapped multiple logistic regressions were applied to describe the associations between the selected predictor variables and labor market participation, controlling for sociodemographic and SCI-related characteristics. RESULTS: A total of 568 (58.8%) of the participants were involved in paid work at the time of the survey. From the 17 selected predictor variables, general functional independence and Swiss citizenship showed a significant positive association, and chronic pain a negative association with involvement in paid work. CONCLUSIONS: Beyond previously established sociodemographic and injury-related risk factors such as female gender, low education, and high lesion severity, functional independence, chronic pain, and nationality proved crucial for labor market participation. These factors should receive particular attention in medical and vocational strategies striving for a sustainable work integration of persons with SCI.

Validation of the World Health Organization Disability Assessment Schedule 2.0 in adults with spinal cord injury in Taiwan: a psychometric study.

STUDY DESIGN: Psychometric study including exploratory factor analysis and Rasch analysis. OBJECTIVE: The aim of the present study was to examine the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) in terms of its dimensionality and metric properties in a sample of people with spinal cord injury (SCI). SETTING: Two hundred and thirty-nine hospitals in Taiwan METHODS: Secondary analysis of cross-sectional data from the National Disability Determination System in Taiwan, including data of individuals with more than 1-year chronic spinal cord injury and over 18 years of age. We would ask the all 6 domains of WHODAS 2.0, except those participants who were not working in present, based on the WHODAS 2.0 manual. RESULTS: Data from 521 persons were included. The internal consistency of WHODAS 2.0 was high for all six domains (Cronbach's α between 0.87-0.99). The exploratory factor analysis supported the original six domain structure of WHODAS 2.0 to a large extent. Rasch analysis provided domain scores usable for measurement at the individual level and an overall WHODAS 2.0 score that takes into account the multidimensionality of the instrument. CONCLUSIONS: WHODAS 2.0 provides a reliable and valid instrument to measure relevant aspects of "activity and participation" in the context of functioning in people with SCI in Taiwan and may guide their rehabilitation.