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

Marcel W M Post; Carolina S Fellinghauer; Susan Charlifue; Peter W New; Martin B Forchheimer; Denise G Tate

doi:10.1016/j.apmr.2022.02.018

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

Arch Phys Med Rehabil. 2022 Nov;103(11):2120-2130. doi: 10.1016/j.apmr.2022.02.018. Epub 2022 Mar 18.

Authors

Marcel W M Post¹, Carolina S Fellinghauer², Susan Charlifue³, Peter W New⁴, Martin B Forchheimer⁵, Denise G Tate⁵

Affiliations

¹ Center of Excellence for Rehabilitation Medicine, UMC Utrecht Brain Center, University Medical Center Utrecht and De Hoogstraat Rehabilitation, Utrecht, the Netherlands; University of Groningen, University Medical Center Groningen, Department of Rehabilitation Medicine, Groningen, the Netherlands. Electronic address: m.post@dehoogstraat.nl.
² Swiss Paraplegic Research, Nottwil, Switzerland.
³ Craig Hospital, Englewood, CO.
⁴ Spinal Rehabilitation Service, Caulfield Hospital, Alfred Health, Melbourne, Victoria, Australia; Epworth-Monash Rehabilitation Medicine Unit, Monash University, Melbourne, Victoria, Australia; Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia.
⁵ Department of Physical Medicine and Rehabilitation, University of Michigan, Ann Arbor, MI.

PMID: 35314170
DOI: 10.1016/j.apmr.2022.02.018

Abstract

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.

Keywords: Psychometrics; Quality of life; Rehabilitation; Spinal cord injuries; Validation studies.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cross-Sectional Studies
Female
Humans
Male
Middle Aged
Psychometrics
Quality of Life* / psychology
Reproducibility of Results
Spinal Cord Injuries* / psychology
Surveys and Questionnaires