Attention is drawn to the fact that the copyright of this thesis rests with the author, and that no quotation from- the thesis and no information denved from it may be published without the prior written consent of the author. Information from the Cornwall and Isles of Scilly Ambulance Service was obtained on the strict understanding that it would remain confidential and should not be. published without prior consent of the Service. Signed AN EVALUATION OF THE USE OF HELICOPTERS AS AIR AMBULANCES by Philip Brigham A thesis submitted to the University of Plymouth in partial fulfilment for the degree of DOCTOR OF PHILOSOPHY Department of Shipping and Transport Faculty of Science In collaboration with the London School of Hygiene and Tropical Medicine September 1993 UNIVERSITY OF PLYMOUTH USHA?iY SHRVICES Item No- I Got 90 0181634 4 Abstract An Evaluation Of The Use Of Helicopters As Air Ambulances, bv Philip Brigham. This study reviews the evaluative literature of air ambulances in other countries and concludes it has little relevance to Britain. Other reviews are undertaken of the British ambulance service, evaluative economics, and market istructures. The relationship between effectiveness, efficiency and equity is explored. It is concluded that there is a role for ak ambulances in servicing rural areas within the revised structure of the' NHS. This is tested by three studies of the Cornwall Ak Ambulance. Initially, the resources and standards of the ambulance service in Cornwall are investigated by analysis of routine data spanning two years. It is concluded that standards of response and times to hospital are poor in North Cornwall. This was deduced from the modelling of response times and time to hospital for incidents from every electoral ward in the county. Two options of 'land ambulance only' and 'land ambulance with the air ambulance' are tested for effectiveness, equity and efficiency. The first study considers the effectiveness of service provision, while the second study considers geographic equity with the use of simple regression analysis to indicate the cost of service provision at differing levels of rurality. The^third uses a cost benefit analysis framework to indicate the costs and benefits associated with air ambulance use in a rural area. The contribution to knowledge is highly significant in the modelling of routine data to assess the effectiveness, efficiency and equity relationship, in appraising accessibility. This is the first study to apply economic principles to the ambulance service within the recently revised NHS. CONTENTS Section One. CHAPTER 1. INTRODUCTION Operational Advantages of AAs 3 Competition and the Ambulance Service 5 Aims and Objectives- 10 Approach 11 Structure of Thesis 12 CHAPTER 2. AIR AMBULANCE LITERATURE REVIEW Introduction 14 Helicopter Emergency Medical Services and Trauma Centres 15 Team Composition 19 Triage, or the Assessment of the Nature and Degree of Injury 20 Speed Response or Delivery 21 Ambulance Utilisation 21 System Evaluation 23 Summary 26 CHAPTER 3. BRITISH AMBULANCE SERVICE Introduction 28 Paramedic Training 29 Organisation Problems 32 Tiering 34 Trusts 35 The Management of Patients with Serious Injuries 37 British AAs 39 Limitations 41 Funding 42 Summary 43 CHAPTER 4. LITERATURE REVIEW OF EVALUATIVE ECONOMICS Introduction 45 Effectiveness 45 Effectiveness of Access 47 Effectiveness of Quality 48 Effectiveness of integration. 49 • Cost Efficiency .49 Managerial Efficiency 51 Technical, Industrial and Allocative Efficiency 54 Social and Distibutional Efficiency 55 Summary 58 CHAPTER 5. EQUITY Introduction 59 Illustrated Examples of Land and AA Integration 60 AA use in the Real World 67 Summary 72 CHAPTER 6. THE AMBULANCE SERVICE WITHIN THE INTERNAL MARKET FOR HEALTH 74 Introduction 74 The End of the Keynsian Post-War Consensus 74 The Ideology of the 'New Right' 74 Efficiency Arguments for and Against the Free Market 76 Efficiency the 'New Right' and the NHS 78 The Ambulance Service and the 'New Right' 80 The Contracting Process 82 Diversification, Market Segmentation and Income Generation 85 Public Goods in a Market Environment 88 Effectiveness, Equity and Efficiency Within the Market Structure 89 Summary 91 SECTION 2 CHAPTER 7. DATA AND METHODS Introduction 94 Background and Structure of the Ambulance Service in Cornwall 94 Methodological Problems 96 Study Design 98 Data Sources 100 Electoral Wards 102 Ambulance Service Vehicles, Staff and Financial Information . 103 Hospital Services 103 GP Services 104 Earnings 104 Outline of Methods and Approach to Evaluation 104 Study One Introduction 105 Patterns of Demand 105 Distribution of Patients to Hospital 106 Ambulance Station Demographics 106 Demand Patterns at Each Ambulance Station Area 106 Standards 107 AA Pattern of Use and Travel Times 110 Two Options to Discover the AA's Contribution to Effectiveness, Equity and Efficiency 112 Study Two Introduction 114 Ambulance Service Costs 115 Calculation of Land Ambulance and A A Costs for each option 116 Calculation of A A Costs 116 Measures of Rurality 117 Sparsity and the Craig Index 118 Population Density and Other Measures of Sparsity 120 Study Three Introduction 123 The Ideal Study 124 Public Sector Costs 124 Costs to Families and Society 125 Benefits 125 Available Information 125 The Ambulance Service 125 The Hospital Service 127 Hospital Costs 127 Pfirhary" Care Costs 128 Social Services 128 Costs to Families and Society 128 Dkect Costs of Illness to Families 128 Costs Attributable to Loss of Productive Activity 129 Costs Attributable to Pain, Suffering and Death 130 Summary 132 CHAPTER EIGHT. AMBULANCE SERVICE EFFECTIVENESS Introduction 133 Patterns of Demand for Emargency and Urgent Calls 133 Distribution of Patients to Hospital 139 Ambulance Station Demographics 140 Demand Patterns at Each Ambulance Station Area 145 Standards 145 AA Travel Times 148 Resource Level at Each Ambulance Station 152 Utilisation of Vehicles per Shift 153 Two Options to Discover the AA's Contribution to Effectiveness, Equity and Efficiency 155 Option One: Land Ambulance Only 158 Option Two: Full Time AA 159 Comments on The Effectiveness of Each Option 160 CHAPTER 9. RESULTS OF STUDY TWO: EQUITY 164 . Introduction 164 Calculation of Ambulance Station Area Costs 164 Derivation of Independent Variables. 167 Analysis 167 Assumption for the Model 169 Regression of Sparsity and Shared Ambulance Station Costs by Area 173 ^ Results of Regression Analysis 174 Interpretation of Results • 174' Criticism of the Model 177 Equity and the Model 179 Conclusion 180 CHAPTER 10. RESULTS OF STUDY THREE: EFFICIENCY Introduction 181 Public Sector Costs 181 Costs to Families and Society 181 Ambulance Service Costs 181 Option One 183 Option Two 183 Staffing 183 Vehicles 185 AA 187 Hospital Costs 188 Primary Care and Social Services' Costs 189 Costs to Families and Society 191 Direct Costs of Illness to Families 191 Benefits Outside the Ambulance Service 193 Benefits Difficult to Value 195 The Hospital System 195 Primary Care 195 Family and Society 195 Conclusion 198 CHAPTER 11. CONCLUSIONS Introduction .201 Aims and Objectives 201 Implications For Policy 205 Contribution to Knowledge 208 Further Research 210 REFERENCES ' ' " 213 APPENDICES 222 Appendix Al Orcon Standards for Measurement of Performance in Emergency and Urgent Cases 222 Appendix Bl Equity and Justice 225 Appendix CI Variables in Cornwall Ambulance Data 227 Appendbc C2 Emergency and Urgent Calls in the Sample Week Each Month 242 Appendix C3 Wards Attached to Ambulance Stations: Size and Population 243 Appendk Dl Receiving Hospitals for Survey Period 247 Appendbt D2 Mean CaUs per Shift 248 Appendix D3 Staff Allocation to Each Ambulance Station 249 Appendix D4 Vehicle Allocation 250 Appendix D5 Times Involved in Responding to Calls During the Day Shift 251 Appendix D6 Time Spent Responding to Calls During the Night Shift 252 Appendix D7 Day Shift Ambulance Ambulance Utilisation 253 Appendbc D8 Night Shift Ambulance Utilisation 254 Appendbc El Total Fixed Costs P.A. 255 Appendix E2 Annual Variable Costs of Land Ambulance Utilisation 256 Appendix E3 Total Fixed and Variable Costs per Ambulance Station 257 Appendix E4 Land Ambulance Sparsity Regression Model 258 Appendix E6 Fitted Values for Land Ambulance Only 260 Appendix E7 Fitted Values for Land Ambulance with AA 260 Appendix E8 Predicted Costs per head for Each Ambulance Station 260 ENCLOSURES. Enclosure 1. Map 1. Area Covered by Ambulance Stations Enclosure 2. Map 2. Population Density by Ward. • . Enclosure 3. Map 3. Land Ambulance Times to District General Hospital by Ward. Enclosure 4. Map 4. Population Sparsity by Ward •• TABLES LI Varying Cost of Ambulance Services. 6 7.1 Craig's (1989) Classification of Sparsity 119 8.1 Distribution of Patients to Hospitals 139 8.2 Land Ambulance ORCON Figures by Ambulaiice Station 146 8.3 Mean Time to Hospital by Land Ambulance for Emerigency and Urgent Calls- ." 147 8.4 'Total Mission Time' for Each Ambulance Station for Emergency and Urgent Cases 148 8.5 AA Calls by Day of Week Over Survey Period 149 8.6 AA Calls by Month of Year 149 8.7 AA Calls by Type 150 8.8 AA Response Times 150 8.9 Comparison of 'Time to Hospital' and 'Total Mission Time' for Land Ambulances and the AA 156 8.10 Percentage of Calls in North Cornwall Outside ORCON Response Times ' 157 8.11 Response Time Within North Cornwall for Land Ambulance and AA 157 8.12 Demand Rate for North ComwaU 158 8.13 Vehicle Allocation and Utilisation for Day Shift at Each Ambulance Station 159 8.14 Predicted Utilisation and Availabihty for Different Demand Levels 160 8.15 Demand Rate for Calls in North Cornwall 161 8.16 Random Number Simulation: One Iteration 162 8.17 One Iteration of Option One 162 9.1 Alternative Allocations of Joint Fixed Costs Between Ambulance stations Sharing Resources 165 9.2 Apportionment of Costs by Area and Population of Each Ambulance Station 166 9.3 population Density and Sparsity Values for • Each Ambulance Station 168 9.4 Result of the Proportion of Variance Explained from Regression Analysis 169 9.5 Fitted Values for Land Ambulance Only and Land Ambulance with AA 176 9.6 Predicted.