Objective: To recruit a more representative population of patients with parkinsonism (PwP) focusing on those often excluded from research.
Background: PwP who are older, living in a care home, with frailty, multimorbidity, or impaired capacity to consent are typically under-represented in research. This limits the generalisability of findings.
Method: We invited PwP from a single UK centre to participate in a cross-sectional questionnaire study, which included the SHARE-FI75+ frailty tool [1]. Postal invitations were followed by telephone if no response was received and additional support was offered to facilitate participation. For adults with impaired capacity to consent, personal consultees provided information on a patient’s prior views regarding research participation and completed a bespoke questionnaire as their “representative”. The success of these approaches was evaluated, using tests of difference in proportions and means, by comparing the characteristic of recruited participants (1) with external data on participants in the Parkinson’s Real World Impact assesSMent (PRISM) study [2] and patients with prevalent parkinsonism in the Clinical Practice Research Datalink (CPRD) a UK primary care database and (2) using internal data on those recruited with or without intensive engagement.
Results: We approached 1,032 eligible patients, of whom 542 (53%) consented and 477 (46%) returned questionnaires. The gender ratio in PRIME-UK (65% male) closely matched CPRD (61% male), while men were under-sampled in PRISM (46%). The mean age of PRIME participants was 75.9 (SD 8.5) years, whilst it was 75.3 (9.5) years and 65.4 (8.9) years for CPRD patients and PRISM participants respectively.
More intensive engagement enhanced recruitment of females (13.3%; 95% CI 3.8-22.9%; p=0.005), care home residents (6.2%; 1.1-11.2%; p=0.004), patients diagnosed with atypical parkinsonism (13.7%; 5.4-19.9%; p < 0.001) and those with a higher frailty score (mean score 0.2; 0.1-0.2; p<0.001).
Conclusion: These recruitment strategies, including telephone reminders and additional support, resulted in a more representative sample. This better reflects the heterogeneity and clinical complexity of PwP. Failure to include such participants will bias samples towards milder disease and reduce generalisability.
References: [1] Romero-Ortuno R, Soraghan C. A Frailty Instrument for primary care for those aged 75 years or more: findings from the Survey of Health, Ageing and Retirement in Europe, a longitudinal populationbased cohort study (SHARE-FI75+). BMJ Open. 2014;4(12):e006645
[2] Tolosa E, Ebersbach G, Ferreira JJ, Rascol O, Antonini A, Foltynie T, et al. The Parkinson’s RealWorld Impact Assessment (PRISM) Study: A European Survey of the Burden of Parkinson’s Disease in Patients and their Carers. J Parkinsons Dis. 2021;11(3):1309-23
To cite this abstract in AMA style:
E. Tenison, M. Smith, D. Pendry-Brazier, A. Cullen, F. Lithander, Y. Ben-Shlomo, E. Henderson. Reaching the hard-to-reach: the representativeness of patients with parkinsonism recruited to the PRIME-UK cross-sectional study [abstract]. Mov Disord. 2023; 38 (suppl 1). https://www.mdsabstracts.org/abstract/reaching-the-hard-to-reach-the-representativeness-of-patients-with-parkinsonism-recruited-to-the-prime-uk-cross-sectional-study/. Accessed June 15, 2025.« Back to 2023 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/reaching-the-hard-to-reach-the-representativeness-of-patients-with-parkinsonism-recruited-to-the-prime-uk-cross-sectional-study/