Outcome measurement in functional neurological disorder: a systematic review and recommendations

OBJECTIVES: We aimed to identify existing outcome measures for functional neurological disorder (FND), to inform the development of recommendations and to guide future research on FND outcomes.
METHODS: A systematic review was conducted to identify existing FND-specific outcome measures and the most common measurement domains and measures in previous treatment studies. Searches of Embase, MEDLINE and PsycINFO were conducted between January 1965 and June 2019. The findings were discussed during two international meetings of the FND-Core Outcome Measures group.
RESULTS: Five FND-specific measures were identified-three clinician-rated and two patient-rated-but their measurement properties have not been rigorously evaluated. No single measure was identified for use across the range of FND symptoms in adults. Across randomised controlled trials (k=40) and observational treatment studies (k=40), outcome measures most often assessed core FND symptom change. Other domains measured commonly were additional physical and psychological symptoms, life impact (ie, quality of life, disability and general functioning) and health economics/cost-utility (eg, healthcare resource use and quality-adjusted life years).
CONCLUSIONS: There are few well-validated FND-specific outcome measures. Thus, at present, we recommend that existing outcome measures, known to be reliable, valid and responsive in FND or closely related populations, are used to capture key outcome domains. Increased consistency in outcome measurement will facilitate comparison of treatment effects across FND symptom types and treatment modalities. Future work needs to more rigorously validate outcome measures used in this population.

Contributors

Pick, S.
Anderson, D. G.
Asadi-Pooya, A. A.
Aybek, S.
Baslet, G.
Bloem, B. R.
Bradley-Westguard, A.
Brown, R. J.
Carson, A. J.
Chalder, T.
Damianova, M.
David, A. S.
Edwards, M. J.
Epstein, S. A.
Espay, A. J.
Garcin, B.
Goldstein, L. H.
Hallett, M.
Jankovic, J.
Joyce, E. M.
Kanaan, R. A.
Keynejad, R. C.
Kozlowska, K.
LaFaver, K.
LaFrance, W. C., Jr.
Lang, A. E.
Lehn, A.
Lidstone, S.
Maurer, C. W.
Mildon, B.
Morgante, F.
Myers, L.
Nicholson, C.
Nielsen, G.
Perez, D. L.
Popkirov, S.
Reuber, M.
Rommelfanger, K. S.
Schwingenshuh, P.
Serranova, T.
Shotbolt, P.
Stebbins, G. T.
Stone, J.
Tijssen, M. A.
Tinazzi, M.
Nicholson, T. R.

Publication

Journal: J Neurol Neurosurg Psychiatry
Volume:
Issue:
Pages: -
Year: 2020
DOI: 10.1136/jnnp-2019-322180

Further Study Information

Current Stage: Completed
Date: February 2017 - February 2019
Funding source(s): UK National Institute for Health Research (NIHR)


Health Area

Disease Category: Mental health, Neurology

Disease Name: Functional Neurological Disorder

Target Population

Age Range: 18 - 100

Sex: Either

Nature of Intervention: Any

Stakeholders Involved

- Clinical experts
- Patient/ support group representatives
- Researchers

Study Type

- COS for clinical trials or clinical research

Method(s)

- Consensus meeting
- Systematic review

The systematic review was conducted in two parts to identify
1. Publications describing existing FND-specific outcome measures.
2. Randomised controlled trials (RCTs) and prospective intervention studies in FND.

The findings of the reviews were discussed at two international consensus meetings (September 2017, Edinburgh, UK; September 2018, Atlanta, USA) involving 43 members from 12 countries, all with expertise in FND treatment or outcome research. The members represented a range of relevant health professions (neurology, (neuro)psychiatry, (neuro)psychology, physiotherapy and occupational therapy) and patient representation.