Abstract
Dear Professor Bo Norrving,
We have read with interest your article in European Stroke Journal entitled ‘Maximising access to thrombectomy services for stroke in England: A modelling study’, 1 appreciating the objective of establishing an optimal configuration of stroke centres within a national system of care.
Firstly, we write to commend your distinguished commitment to improving patient outcomes in stroke.
We would like to bring to your attention a suspected misquotation on page 40 regarding the population-based study by Rinaldo et al.
2
where you state that: Rinaldo et al.18 have, however, demonstrated that outcomes in high volume centres in the US, with at least 132 ET procedures per year, were better.
Thus, relative to Rinaldo’s study, the model clearly overestimates the caseload for qualification as a comprehensive stroke centre (CSC), setting a minimum requirement of 150 ET procedures per CSC per year. Combining this parameter with the base assumption that 10% of patients admitted to a stroke unit are ET-eligible and thus each CSC will have at least 1500 admissions per year, the algorithm states that the maximum number of CSCs would be 40, with 15% of patients being more than 45 min away from care and CSCs receiving up to 4300 stroke admissions per year. In contrast, the most recent NHS England Configuration Decision Support Guide recommends a maximum of 1500 admissions per CSC per year, 3 and the largest centre in the UK has approximately 2000 admissions per year. 4
If, as per Rinaldo’s study, your algorithm takes into account lower volume centres as CSCs, then there would be a greater maximum number of ET-capable CSCs, faster access to CSCs and reduced risk of unmanageable admission numbers to each CSC. This particularly benefits regional networks by reducing their reliance on primary stroke centres, which compromise time-to-ET for the sake of time-to-intravenous thrombolysis.
Our team has been involved in computational modelling and resource optimisation for ET services and we are strong advocates for improved access to these techniques. Could we respectfully ask you to reconsider the evidence based on Rinaldo’s study and your resultant base assumptions? We believe this reconsideration impacts the described modelling, with direct implications for the proposed service delivery.
Thank you for your consideration. We are eagerly awaiting your response.
Yours sincerely,
Michelle Foo
Julian Maingard
Hong Kuan Kok
Ashu Jhamb
Mark Brooks
Christen Barras
Vincent Thjis
Hamed Asadi
Footnotes
Declaration of conflicting interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
Ethical approval
Not applicable.
Informed consent
Not applicable.
Trial registration
Not applicable.
Guarantor
MF.
Contributorship
All authors contributed to writing, reviewing and approving the final version of this letter.
Acknowledgements
None.
