Measuring quality of life in ALS/MND: validation of the WHOQOL-BREF

Abstract

Objectives: The World Health Organization Quality of Life-BREF Scale (WHOQOL-BREF) is a generic QOL measure with four domains covering Physical, Psychological, Social and Environment. Providing the opportunity to contrast QoL with other conditions, or with population norms, the current study had three aims: 1) can the established domains of the WHOQOL-BREF be validated within a large ALS/MND population; 2) can a total score be validated and 3) can they provide interval level measurement? Methods: Data were obtained from the Trajectories of Outcomes in Neurological Conditions study. Internal construct validity was determined by fit of the data to the Rasch measurement model. Results: 636 participants with ALS/MND were included. All domains, except the Social domain, showed satisfactory fit to the Rasch model. All were unidimensional, and showed no Differential Item Functioning by age, gender, or onset type. Finally, a total score was validated from a bi-factor perspective. Conclusions: The WHOQOL-BREF is valid for use in populations with ALS/MND and can be analyzed to yield interval level measurement: It offers a range of domains that reflect QOL, which can be used for parametric analysis and for comparison with other conditions or general populations, two advantages for its inclusion as a trial outcome measure and for observational studies.

Keywords:

• Amyotrophic lateral sclerosis
• TONiC
• quality of life
• Rasch
• interval level measurement

Acknowledgments

We thank the participants and their families for their invaluable contributions; the research and clinical staff for recruitment, and the TONiC team.

Disclosure of interest

The authors report no conflicts of interest.

Additional information

Funding

This work was supported by the Motor Neurone Disease Association (UK) under grant Young/Jan15/929-794, and also received research support from the NIHR Clinical Research Network, and the Neurological Disability Fund 4530. AAC is supported through the following funding organizations under the egis of JPND - www.jpnd.eu (United Kingdom, Medical Research Council [MR/L501529/1; MR/R024804/1] and Economic and Social Research Council [ES/L008238/1]) and through the Motor Neurone Disease Association. This study represents independent research part-funded by the National Institute for Health Research (NIHR) Biomedical Research Center at South London and Maudsley NHS Foundation Trust and King’s College London. CJM and this research are supported by the NIHR Sheffield Biomedical Research Center and the NIHR Sheffield Clinical Research Facility. CAY and this research are supported by NIHR CRN NWC.