{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,18]],"date-time":"2026-04-18T03:10:06Z","timestamp":1776481806333,"version":"3.51.2"},"reference-count":22,"publisher":"BMJ","issue":"7","license":[{"start":{"date-parts":[[2023,7,17]],"date-time":"2023-07-17T00:00:00Z","timestamp":1689552000000},"content-version":"unspecified","delay-in-days":16,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000883","name":"University of Bristol","doi-asserted-by":"publisher","award":["NA"],"award-info":[{"award-number":["NA"]}],"id":[{"id":"10.13039\/501100000883","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000274","name":"British Heart Foundation","doi-asserted-by":"publisher","award":["CH\/1992027\/7163"],"award-info":[{"award-number":["CH\/1992027\/7163"]}],"id":[{"id":"10.13039\/501100000274","id-type":"DOI","asserted-by":"publisher"}]},{"name":"NIHR Biomedical Research Centre","award":["NA"],"award-info":[{"award-number":["NA"]}]},{"DOI":"10.13039\/100012141","name":"University Hospitals Bristol and Weston NHS Foundation Trust","doi-asserted-by":"crossref","award":["NA"],"award-info":[{"award-number":["NA"]}],"id":[{"id":"10.13039\/100012141","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2023,7,4]]},"published-print":{"date-parts":[[2023,7]]},"abstract":"<jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>To model the referral, diagnostic and treatment pathway for cardiovascular disease (CVD) in the English National Health Service (NHS) to provide commissioners and managers with a methodology to optimise patient flow and reduce waiting lists.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Study design<\/jats:title>\n                    <jats:p>A systems dynamics approach modelling the CVD healthcare system in England. The model is designed to capture current and predict future states of waiting lists.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Setting<\/jats:title>\n                    <jats:p>Routinely collected, publicly available data streams of primary and secondary care, sourced from NHS Digital, NHS England, the Office of National Statistics and StatsWales.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Data collection and extraction methods<\/jats:title>\n                    <jats:p>The data used to train and validate the model were routinely collected and publicly available data. It was extracted and implemented in the model using the PySD package in python.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>NHS cardiovascular waiting lists in England have increased by over 40% compared with pre- COVID-19 levels. The rise in waiting lists was primarily due to restrictions in referrals from primary care, creating a bottleneck postpandemic. Predictive models show increasing point capacities within the system may paradoxically worsen downstream flow. While there is no simple rate-limiting step, the intervention that would most improve patient flow would be to increase consultant outpatient appointments.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>The increase in NHS CVD waiting lists in England can be captured using a systems dynamics approach, as can the future state of waiting lists in the presence of further shocks\/interventions. It is important for those planning services to use such a systems-oriented approach because the feed-forward and feedback nature of patient flow through referral, diagnostics and treatment leads to counterintuitive effects of interventions designed to reduce waiting lists.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjopen-2022-065622","type":"journal-article","created":{"date-parts":[[2023,7,19]],"date-time":"2023-07-19T23:46:05Z","timestamp":1689810365000},"page":"e065622","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":13,"title":["Process modelling of NHS cardiovascular waiting lists in response to the COVID-19 pandemic"],"prefix":"10.1136","volume":"13","author":[{"given":"Salvador","family":"Catsis","sequence":"first","affiliation":[{"name":"Department of Engineering Mathematics, University of Bristol, Bristol, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alan R","family":"Champneys","sequence":"additional","affiliation":[{"name":"Department of Engineering Mathematics, University of Bristol, Bristol, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1645-1071","authenticated-orcid":false,"given":"Rebecca","family":"Hoyle","sequence":"additional","affiliation":[{"name":"Department of Mathematics, University of Southampton, Southampton, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Christine","family":"Currie","sequence":"additional","affiliation":[{"name":"Department of Mathematics, University of Southampton, Southampton, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jessica","family":"Enright","sequence":"additional","affiliation":[{"name":"Department of Mathematics, University of Glasgow, Glasgow, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Katherine","family":"Cheema","sequence":"additional","affiliation":[{"name":"British Heart Foundation, London, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mike","family":"Woodall","sequence":"additional","affiliation":[{"name":"NHS Midlands and Lancashire Commissioning Support Unit, West Bromwich, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1753-3730","authenticated-orcid":false,"given":"Gianni","family":"Angelini","sequence":"additional","affiliation":[{"name":"Cardiac Surgery, University of Bristol, Bristol, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9895-9356","authenticated-orcid":false,"given":"Ramesh","family":"Nadarajah","sequence":"additional","affiliation":[{"name":"Leeds Institute for Data Analytics, University of Leeds, Leeds, UK"},{"name":"Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chris","family":"Gale","sequence":"additional","affiliation":[{"name":"Leeds Institute for Data Analytics, University of Leeds, Leeds, UK"},{"name":"Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3635-6212","authenticated-orcid":false,"given":"Ben","family":"Gibbison","sequence":"additional","affiliation":[{"name":"Cardiac Anaesthesia and Intensive Care, University of Bristol, Bristol, UK"},{"name":"Department of Cardiac Anaesthesia, University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2023,7,19]]},"reference":[{"key":"2025121601022869000_13.7.e065622.1","unstructured":"British Heart Foundation . 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