REPORT 2019 HEALTH TECHNOLOGY ASSESSMENT: Prehospital CT for early diagnosis and treatment of suspected acute stroke or severe head injury Published by The Norwegian Institute of Public Health Division of Health Services Title Prehospital CT for early diagnosis and treatment of suspected acute stroke or severe head injury. A health technology assessment. Norwegian title Prehospital CT for tidlig diagnostikk og behandling ved mistanke om hjerneslag eller al- vorlige hodeskader. En metodevurdering. Responsible Camilla Stoltenberg, Director-General Authors Sari Susanna Ormstad, project leader, Senior Adviser, Norwegian Institute of Public Health Ulrikke Højslev Lund, Adviser, Norwegian Institute of Public Health Kishan Kumar Chudasama, Senior Adviser, Norwegian Institute of Public Health Katrine Bjørnebek Frønsdal, Senior Researcher, Norwegian Institute of Public Health Maren Ranhoff Hov, MD PhD, Oslo University Hospital and The Norwegian Air Ambulance Foundation Ida Ormberg, Senior Adviser, Norwegian Radiation and Nuclear Safety Authority Elisabet Hafstad, Senior Adviser, Norwegian Institute of Public Health Anna Stoinska-Schneider, Senior Adviser, Norwegian Institute of Public Health Bjarne Robberstad, Senior Researcher, Norwegian Institute of Public Health Vigdis Lauvrak, Senior Researcher, Norwegian Institute of Public Health Lene Kristine Juvet, Department Director, Norwegian Institute of Public Health ISBN 978-82-8406-005-7 Project number ID2016_009 Type of publication Health technology assessment No of pages 93 (138 including appendices) Client Bestillerforum RHF Subject Heading Stroke; Craniocerebral Trauma; Tomography Scanners, X-Ray Computed; Tomography, (MeSH) X-Ray Computed; Ambulances; Mobile Health Units; Time-to-Treatment; Triage; System- atic Review; Technology Assessment, Biomedical Citation Ormstad SS, Lund UH, Chudasama KK, Frønsdal KB, Hov MR, Ormberg I, Hafstad E, Stoinska-Schneider A, Robberstad B, Lauvrak V, Juvet LK. Prehospital CT for early diagnosis and treatment of suspected acute stroke or severe head injury. A health technology assessment. Rapport − 2019. Oslo: Folkehelseinstituttet, 2019. 1 Table of contents Table of contents TABLE OF CONTENTS 2 KEY MESSAGES 4 EXECUTIVE SUMMARY 5 HOVEDBUDSKAP (NORWEGIAN) 9 SAMMENDRAG (NORWEGIAN) 10 LIST OF ABBREVIATIONS AND ACRONYMS 14 PREFACE 16 OBJECTIVES 18 BACKGROUND 19 Acute stroke and severe head injuries 19 Current diagnostic and treatment pathways 21 Prehospital CT 23 Radiation protection regulations 25 CLINICAL EFFECTIVENESS AND SAFETY 27 Methods 27 Inclusion criteria 27 Literature search 29 Study selection 30 Assessment of risk of bias in included studies 30 Data extraction 30 Data analysis 31 Assessment of certainty of the evidence 31 Results 33 Search results and selection of studies 33 Description of included studies 34 Risk of bias in included studies 39 Effectiveness and safety of prehospital CT 41 2 Table of contents ORGANIZATIONAL ASPECTS 52 Current diagnostic and treatment pathways in Norway 52 Implementation of prehospital CT 54 HEALTH ECONOMIC EVALUATION 58 Methods 58 Introduction to economic evaluations of health care programmes 58 Priority setting criteria 59 Summary of other economic evaluations 60 General 61 Cost- and threshold analysis 62 Epidemiology and patient flow assumptions 63 Markov model assumptions and parameters 64 Sensitivity cost- and threshold analysis 70 Budget impact 70 Results 71 Severity considerations 71 Cost- and threshold analysis 71 Sensitivity cost- and threshold analysis 73 DISCUSSION 76 Main findings and certainty of the evidence 76 Strengths and weaknesses 80 Comparison with other studies 83 Applicability of the findings and implications for practice 83 Future research 84 CONCLUSION 86 REFERENCES 87 APPENDICES 94 Appendix 1. Differences between project plan and assessment 94 Appendix 2. Search strategies 95 Appendix 3. Excluded publications and reasons for exclusion 108 Appendix 4. List of ongoing studies 121 Appendix 5. Characteristics of included studies and risk of bias 123 Appendix 6. GRADE evidence profiles 133 Appendix 7. Additional results tables 135 Appendix 8. Decision tree illustrating the Markov model structure with possible transitions 138 3 Table of contents Key messages In Norway, approximately 12,000 persons experience Title: acute stroke each year. Time is a crucial factor in the Prehospital CT for early diagnosis and management of stroke, so rapid admission to a hospital treatment of suspected acute stroke or for a computed tomography (CT) scan is recom- severe head injury. A health technology mended. assessment. ----------------------------------------- A mobile stroke unit (MSU), an ambulance equipped Type of publication: with a CT scanner, helps bring the hospital to the pa- Health technology assess- tient. Research evidence indicates that, compared with ment (HTA) conventional care of acute stroke, MSU care probably Health technology assessment (HTA) is leads to: a multidisciplinary process that summa- reduced time from patient’s first contact with the rizes information about the medical, so- cial, economic and ethical issues related emergency dispatch center to thrombolysis to the use of a health technology in a (treatment with a clot dissolving agent) systematic, transparent, unbiased, ro- increased number of patients who receive bust manner. Its aim is to inform the de- thrombolysis velopment of safe, effective health poli- cies that are patient focused and that MSU care may also lead to: seek to achieve best value. reduced time from patient’s first contact with the ----------------------------------------- emergency dispatch center to CT imaging Doesn’t answer everything: better functionality at 3 months after stroke. We did not address ethical, legal or social aspects related to prehospital CT ----------------------------------------- Our cost- and threshold analysis found that: One MSU is estimated to cost approximately 6.4 million Who is responsible for this publica- Norwegian kroner annually. The health gain measured tion? in quality-adjusted life-years (QALYs) was 0.3 per The Norwegian Institute of Public Health completed this HTA, patient receiving thrombolysis through MSU care which was commissioned by compared with conventional care. We performed an Bestillerforum RHF. analysis quantifying the severity criterion by ----------------------------------------- calculating absolute shortfall for patients with acute When were the literature searches ischemic stroke who receive conventional care. The conducted? results show an absolute shortfall of 5.5 QALYs. We December 2017, December 2018 found that the expected cost per QALY is ----------------------------------------- approximately 385,000 Norwegian kroner or lower if Peer review: one MSU successfully reaches at least 35-40% (145- Professor Jan Malm, Umeå University 171) of thrombolysis patients per year. Associate Professor Eline Aas, Univer- sity of Oslo 4 Key messages Executive summary Background Stroke is the second leading mortality cause in most Western countries, and a major cause of adult disability. In Norway, approximately 12,000 persons experience acute stroke each year. In 2017, 8,789 cases of acute stroke were recorded in the Norwegian Stroke Registry (covering 86% of acute stroke patients). Head injuries also constitute a large group of patients arriving at the emergency ward, and are the leading cause of death in persons under the age of 44 years. Those considered to have severe injury re- quire urgent admission to a neurosurgical department. In acute stroke and severe head injuries, it is crucial that the patient is diagnosed and treated as soon as possible ("time is brain"). If acute stroke or severe head injury is sus- pected, rapid admission to a hospital to undertake a computed tomography (CT) scan is recommended. In stroke caused by blood clots (ischemic stroke or cerebral infarction), thrombolytic treatment should be given as soon as possible, at most within 4.5 hours after the onset of symptoms. In hemorrhagic stroke (bleeding), on the other hand, thrombolytic treatment is contra-indicated as it may cause life-threatening complica- tions. Thus it is crucial to determine as soon as possible the cause of the stroke in order to provide appropriate treatment. In head injuries, CT imaging allows the identification of those patients who require urgent admission to a neurosurgical department. Prehospital CT, either performed in a mobile stroke unit (ambulance equipped with a CT scanner) or in "a CT scanner station" located outside hospital, is a novel approach that brings the hospital closer to the patient. It seeks to shorten the time to diagnosis and treatment, as well as to determine which treatment facility the patient should be directed to. Objective The aim of this health technology assessment (HTA) is to compare the clinical effective- ness and safety of prehospital CT for early diagnosis and potential prehospital treat- ment of suspected acute stroke or severe head injury with current practice of diagnosis and treatment carried out after arrival in the hospital. Furthermore, it seeks to shed light on organizational and health economic consequences related to the implementa- tion of prehospital CT in Norway. Method Clinical effectiveness and safety 5 Executive summary In absence of eligible systematic reviews and HTAs, we conducted systematic searches for primary studies in a selection of relevant databases and trials registries. We limited the searches to publication year 2010 to present, but no restrictions