Measuring disability in amyotrophic lateral sclerosis/motor neuron disease: the WHODAS 2.0-36, WHODAS 2.0-32, and WHODAS 2.0-12

Abstract

Aim: To investigate whether the World Health Organization Disability Assessment Schedule 2.0 (WHODAS) can provide interval level measurement of disability in Amyotrophic Lateral Sclerosis (ALS), allowing parametric analyses. Methods: Data on the WHODAS 12, 32, and 36-item versions, from 1120 patients studied at one or more time points, were fit to the Rasch model and comparisons made against ALSFRS-R, King’s staging, and mortality. Trajectory modeling was undertaken for a newly diagnosed (≤6 months) cohort of 454 individuals. Results: Total scores for WHODAS 32 and 36-item versions can be converted to interval level measurement suitable for individual clinical use, and the 12-item WHODAS total for group use. The 36-item version is shown to be equivalent to the 32-item version. Expected correlations were seen with King’s staging, ALSFRS-R, and EQ-5D-5L. Trajectory analysis of disability (WHODAS 2.0) showed three clearly demarcated groups with differences in King’s staging, depressive symptomatology and mortality, but not age. Conclusions: The WHODAS 2.0 is a brief patient reported outcome measure which can be used to measure disability in ALS. Provided the patient answers all 36 (32 if not working) items, the conversion table produces an interval level estimate for parametric analyses. The different trajectories demonstrated from diagnosis support the concept of a prodromal period, and suggest the WHODAS 2.0 could be used for surveillance of at risk populations, such as those with genetic predisposition.

Keywords:

• World Health Organization Disability Assessment Schedule 2.0
• Rasch
• disability
• Trajectories of Outcomes in Neurological Conditions-ALS
• patient reported outcome measure

Acknowledgements

The authors sincerely thank all the people with ALS/MND and their families who contributed to this study; staff from MND Care Centres in Basildon, Brighton, Cambridge, Cumbria, Dartford & Gravesham NHS Trust, Edinburgh, Exeter, Kings’ College London, Leicester, Liverpool, London North West, London North East, Maidstone, Manchester, Newcastle, North Devon, Norwich, Oxford, Peterborough, Portsmouth, Plymouth, Preston, Sheffield, Shropshire, Southampton, South Wales MND Care Network (Cardiff, Swansea, Cwm Taf and Hywel Dda Clinics), Stoke on Trent, Swansea, West Suffolk, Worcester for identifying and caring for study patients; the research and clinical staff for recruitment and data collection; and the TONiC team.

Declaration of interest

No potential conflict of interest was reported by the author(s). No funding source had involvement in the study design, analysis, interpretation of data, or preparation of the manuscript.

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. A.A.C. is an NIHR Senior Investigator and was supported through the following funding organizations under the egis of JPND - www.jpnd.eu (UK, 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. C.J.M. and this research were supported by the NIHR Sheffield Biomedical Research Center and the NIHR Sheffield Clinical Research Facility. C.A.Y. and this research were supported by NIHR CRN NWC.