The Cortical Basal ganglia Functional Scale (CBFS): Development and preliminary validation

Anthony E Lang; Glenn T Stebbins; Ping Wang; Edwin Jabbari; Ruth Lamb; Huw Morris; Adam L Boxer; 4RTNI; PROSPECT-M-UK investigators

doi:10.1016/j.parkreldis.2020.08.021

The Cortical Basal ganglia Functional Scale (CBFS): Development and preliminary validation

Parkinsonism Relat Disord. 2020 Oct:79:121-126. doi: 10.1016/j.parkreldis.2020.08.021. Epub 2020 Aug 25.

Authors

Anthony E Lang¹, Glenn T Stebbins², Ping Wang³, Edwin Jabbari⁴, Ruth Lamb⁵, Huw Morris⁴, Adam L Boxer³; 4RTNI; PROSPECT-M-UK investigators

Collaborators

A Boxer Pi⁶, B Boeve⁶, B Dickerson⁷, M Grossman⁸, I Litvan⁹, P Ljubenkov¹⁰, A Pantelyat¹¹, J Rojas-Martinez¹⁰, M-C Tartaglia¹², A-M Wills¹³, H Morris Pi¹⁴, K Amar¹⁴, E Capps¹⁵, G Carey¹⁶, A Church¹⁷, P Critchley¹⁸, B Ghosh¹⁹, H Houlden²⁰, M Hu²⁰, Edwin Jabbari²¹, C Kobylecki²², L Massey²³, S Molloy²⁴, U Nath²⁵, N Pavese²⁶, J B Rowe²⁷

Affiliations

¹ Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital and the Department of Medicine (Neurology), University of Toronto, Toronto, Canada. Electronic address: [email protected].
² Department of Neurological Sciences, Rush University Medical Center, Chicago, USA.
³ Department of Neurology, Memory and Aging Center, University of California, San Francisco, CA, USA.
⁴ Department of Clinical and Movement Neuroscience, Institute of Neurology, University College London, UK.
⁵ Clinical Neurosciences, Royal London Hospital, London, UK.
⁶ Department of Neurology, Mayo Clinic, Rochester, MN.
⁷ Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA.
⁸ Department of Neurology, University of Pennsylvania, Philadelphia, PA.
⁹ Department of Neurology, University of California, San Diego, CA.
¹⁰ Department of Neurology, University of California, San Francisco, CA.
¹¹ Department of Neurology, Johns Hopkins University, Baltimore, MD.
¹² Department of Medicine (Neurology), University of Toronto, Toronto, ON.
¹³ Department of Neurology, Massachusetts General Hospital, Boston, MA.
¹⁴ Royal Bournemouth and Christchurch NHS FT, Dorset, UK.
¹⁵ Shrewsbury and Telford Hospital NHS Trust, UK.
¹⁶ Department of Neurology, Ashford and St Peter's Hospital NHS Foundation Trust, Ashford, UK.
¹⁷ Department of Neurology, Royal Gwent Hospital, UK.
¹⁸ Department of Neurology, University Hospitals Leciester NHS Trust, Lecister, UK.
¹⁹ Wessex Neurological Centre, University Hospital Southampton, UK.
²⁰ Oxford Parkinson's Disease Centre (OPDC) and Nuffield Department of Clinical Neurosciences, University of Oxford, UK.
²¹ Department of Clinical and Movement Neurosciences, Institute of Neurology, UCL, UK.
²² Manchester Centre for Clinical Neurosciences, Salford Royal NHS Foundation Trust, UK.
²³ Department of Neurology, Poole Hospital NHS Foundation Trust, Poole, UK.
²⁴ London North West University Healthcare NHS Trust, UK.
²⁵ Sunderland Royal Hospital, UK.
²⁶ Clinical Ageing Research Unit, Newcastle University, UK.
²⁷ Department of Clinical Neurosciences, Cambridge University, UK.

PMID: 32947108
DOI: 10.1016/j.parkreldis.2020.08.021

Abstract

Objective: To develop a patient/care-giver reported scale capable of easily and reliably assessing functional disability in 4 repeat tauopathies (4RTs).

Background: 4R tauopathies including progressive supranuclear palsy, corticobasal degeneration and a subset of frontotemporal dementias manifest a range of overlapping clinical phenotypes. No available rating scale is capable of evaluating the functional impact of these complex disorders.

Methods: A multi-staged modified Delphi process was used to propose, evaluate and rank potential scale items providing content validity ratios. Staged cognitive pretesting involving input from examiners, patients and caregivers was followed by validation testing in patients participating in the 4R Tauopathy Neuroimaging Initiative or the PROgressive Supranuclear Palsy CorTico-Basal Syndrome MSA Longitudinal Study. Clinimetric properties were examined using classical test theory and item response methods, assessing data quality, reliability, construct validity, convergent validity and known-group validity.

Results: The resultant Cortical Basal ganglia Functional Scale (CBFS) included questions on Motor Experiences in Daily Living (14 items) and Non-Motor Experiences of Daily Living (17 items). Reliability was acceptable for internal consistency, test-retest stability, item discrimination, item-scaling thresholds and item-fit. Examination of construct validity revealed a parsimonious two-factor solution, and concurrent validity demonstrated significant correlations between the CBFS and other measures of disease severity and functional impairment. The CBFS significantly discriminated between all diagnostic groups and controls (all AUCs>90). The CBFS scores demonstrated sensitivity to change over a 12 month follow-up in patients with probable 4RTs.

Conclusions: The CBFS is a patient/care-giver reported outcome measure with excellent clinimetric properties that captures disability correlated with motor, cognitive and psychiatric impairments.

Keywords: 4 repeat tauopathies; Clinical rating scales; Corticobasal degeneration; Outcome measures; Patient reported outcomes; Progressive supranuclear palsy.

Publication types

Research Support, N.I.H., Extramural

MeSH terms

Corticobasal Degeneration / diagnosis*
Delphi Technique
Female
Frontotemporal Dementia / diagnosis*
Humans
Longitudinal Studies
Male
Middle Aged
Patient Reported Outcome Measures*
Psychometrics / instrumentation
Psychometrics / methods
Psychometrics / standards
Reproducibility of Results
Severity of Illness Index*
Supranuclear Palsy, Progressive / diagnosis*

Abstract

Publication types

MeSH terms

Grants and funding