Handbook of Evidence-Based Veterinary Medicine (eBook)

Peter Cockcroft, Mark Holmes (Autoren)

eBook Download: PDF

2008
John Wiley & Sons (Verlag)
978-0-470-68054-4 (ISBN)

Infos

The application of evidence-based veterinary medicine (EBVM) can assist in improving and optimising the diagnosis, prognosis, control, treatment and ultimately the welfare of animals. It can also provide the user with a methodology for appropriate, patient orientated life-long, self-directed, learning. To practise evidence-based veterinary medicine we require a range of skills that we may not have.

This book explains what evidence-based veterinary medicine is and shows how it can be applied to veterinary practice to improve the quality of care for patients and provide informed choices for owners. It provides the reader with a toolkit of skills necessary to practise evidence-based veterinary medicine.

This book is aimed at practitioners but will be of interest to veterinary surgeons at any stage of their training or career wishing to learn about EBVM.

The authors are responsible for devising and teaching an EBVM course at the veterinary school at Cambridge.

Dr Peter Cockcroft, Clinical lecturer, Department of Clinical Veterinary Medicine, University of Cambridge.

Dr Mark Holmes, Senior lecturer in Preventive Veterinary Medicine, Department of Clinical Veterinary Medicine, University of Cambridge.

Inhalt

Handbook of Evidence-based Veterinary Medicine 1
Contents 7
Preface 15
Acknowledgements 16
1 Introduction 17
1.1 Who is this book for? 18
1.2 Who isn't this book for? 18
1.3 What do we mean by EBVM? A brief description 19
1.4 Comparison of the traditional methods and EBVM 20
1.5 Why should we practise EBVM? 20
1.5.1 Because we can 20
1.5.2 Because our clients can too 21
1.5.3 We need the information 21
1.5.4 Time for learning, a diminishing resource faced with expanding demands 24
1.5.5 Increasing the speed of adopting the results of science 24
1.5.6 To better direct clinical research 25
1.5.7 Ethical aspects of proof 25
1.5.8 Ethical conduct in the absence of scientific evidence 26
1.5.9 A return to science 27
1.5.10 Are we ready to ask questions about our own performance? 27
1.6 A more detailed description of EBVM 27
1.6.1 The process 27
1.6.2 The need for evidence 29
1.6.3 Other sources of information and evidence 30
1.7 EBM in human medicine 30
1.8 EBM in veterinary medicine 30
1.9 Are we already practising EBVM? 32
1.10 EBVM case studies 32
1.10.1 Small animals: megavoltage radiotherapy of nasal tumours in dogs 32
1.10.2 Farm animals: restocking after foot and mouth disease 33
1.10.3 Horses: efficiency of prednisolone for the treatment of heaves (COPD) 34
1.11 How this book is organised 35
1.11.1 The aims and objectives of this book 35
1.11.2 Outline of the structure of this book 35
References and further reading 36
Review questions 38
2 Turning Information Needs into Questions 39
2.1 Introduction 40
2.2 Refining clinical questions so that evidence can be found 40
2.2.1 Is this a good treatment for a disease? 40
2.2.2 How good is a test? 40
2.3 Four main elements of a well-formed clinical question 41
2.3.1 Patient or problem 41
2.3.2 The diagnostic or therapeutic intervention, prognostic factor or exposure 41
2.3.3 Comparison of interventions (if appropriate or required) 41
2.3.4 The outcome 42
2.4 Categorising the type of question being asked 42
2.5 Prioritising the questions 42
2.6 Checklist of information needs 42
2.6.1 Epidemiological risk factors 43
2.6.2 Diagnostic process 43
2.6.3 Treatment 44
2.6.4 Harm/aetiology 45
2.6.5 Prognosis 45
2.6.6 Control (risk reduction) and prevention (risk avoidance) 46
2.7 Potential pitfalls in constructing questions 46
2.7.1 Complexity of the questions 47
2.7.2 The need for sufficient background knowledge 47
2.7.3 More questions than time 47
2.8 Realistic targets for veterinary practice 47
2.9 Evidence of quality control 48
Further reading 48
Review questions 49
3 Sources of Information 50
3.1 Introduction 51
3.2 Background and foreground knowledge 51
3.3 Hierarchy of evidence 51
3.4 Important traditional information resources 53
3.4.1 Journals 53
3.4.2 Textbooks and other review type publications 55
3.4.3 Personal experience and background knowledge 55
3.4.4 Colleagues 56
3.4.5 Practice records 56
3.5 The Internet 56
3.6 Veterinary information resources on the Internet 58
3.6.1 CABdirect 58
3.6.2 Consultant 59
3.6.3 Inno-vet 59
3.6.4 International Veterinary Information Service 59
3.6.5 Medline/Pubmed 60
3.6.6 The Merck Veterinary Manual 64
3.6.7 Montreal Veterinary School 64
3.6.8 NetVet and the Electronic Zoo 65
3.6.9 RCVS and RCVS library 66
3.6.10 VetGate 66
3.6.11 VIN 66
3.6.12 Wildlife Information Network 67
3.7 Other computer-based information resources 67
3.7.1 BSAVA 68
3.7.2 CLIVE 68
3.7.3 Lifelearn 68
3.7.4 Vetstream 68
3.8 Critically appraised topics 69
Further reading 69
Review questions 70
4 Searching for Evidence 71
4.1 Introduction 72
4.2 RCVS library 72
4.3 Other online book catalogues 72
4.4 Consultant 73
4.5 Searching strategies: simple Boolean logic 73
4.6 Using Pubmed 74
4.7 Sensitivity and specificity 76
4.8 Special veterinary considerations 76
4.9 Searching for the answers to questions about therapy 77
4.10 Searching for the answers to questions about diagnosis 78
4.11 Searching for the answers to questions about aetiology 78
4.12 Searching for the answers to questions about prognosis 78
4.13 Using the 'Clinical Queries' option in Pubmed 79
4.14 Depth of the veterinary scientific literature 79
4.15 Developing searching skills 81
References and websites 81
Review questions 82
5 Research Studies 83
5.1 Hierarchy of evidence and experimental design 84
5.2 Guide to research methods 85
5.3 Literature reviews 85
5.3.1 Systematic reviews 86
5.3.2 Meta-analyses 86
5.4 Experimental studies 87
5.4.1 Randomised controlled trials 87
5.4.2 Cross-over designs 89
5.5 Observational studies 89
5.5.1 Cohort studies 90
5.5.2 Cross-sectional survey 91
5.5.3 Case-control studies 92
5.6 Diagnostic tests and screening tests 94
5.7 Poorly controlled or uncontrolled trials 94
5.7.1 Comparisons between groups at different times 94
5.7.2 Comparisons between different places 94
5.7.3 n = 1 trials (the 'treat and see' method) 95
5.7.4 Uncontrolled trials (before and after trials) 95
5.7.5 Non-random allocation trials 95
5.8 Descriptive studies 95
5.8.1 Surveys 95
5.8.2 Case series and case reports 96
Further reading 97
Review questions 98
6 Appraising the Evidence 100
6.1 Some introductory concepts 101
6.1.1 The importance of statistics 101
6.1.2 Likelihood: probability and odds 102
6.1.3 Risk and uncertainty 103
6.2 Appraising articles on veterinary therapy 104
6.2.1 Is the study valid? 104
6.2.2 Are the results important? 106
6.2.3 Quantifying the risk of benefit or harm 106
6.2.4 Confidence intervals (CIs) 108
6.2.5 Making a decision about therapy 109
6.3 Appraising articles on veterinary diagnosis 109
6.3.1 Is the study valid? 110
6.3.2 Are the results important? 111
6.3.3 SpPin and SnNout 114
6.3.4 Making a decision about a diagnostic test 114
6.4 Appraising articles on harm or aetiology 114
6.4.1 Is the study valid? 116
6.4.2 Are the results important? 117
6.4.3 Statistical analysis 118
6.5 Appraising studies on prognosis 118
6.5.1 Is the study valid? 119
6.5.2 Are the results important? 120
References and further reading 120
Review questions 121
Solution to the probability example used in Section 1 122
7 Diagnosis 123
7.1 Introduction 124
7.2 Definitions 124
7.2.1 Types of diagnosis 125
7.3 The clinical examination: evidence for the presence of disease 126
7.4 Hypothetico-deductive reasoning 127
7.5 The diagnostic process 128
7.6 Recall and ranking 130
7.6.1 Pattern matching 130
7.6.2 Probabilities 130
7.6.3 Pathophysiological reasoning (functional reasoning) 131
7.7 Which method of pattern recognition is used? 132
7.8 Clinical reasoning strategies used in hypothetico-deductive reasoning 132
7.8.1 The properties of clinical signs 132
7.8.2 Logical exclusion of a disease 133
7.8.3 Inductive and deductive reasoning 133
7.8.4 Abstraction/aggregation 133
7.8.5 Prevalence 134
7.9 Errors in hypothetico-deductive reasoning 134
7.10 Logic, sets, Venn diagrams, Boolean algebra 135
7.10.1 Clinical sign sensitivities 136
7.10.2 Disease subsets 136
7.10.3 Venn diagrams and Boolean algebra 136
7.11 Clinical staging of metritis in cattle 138
References and further reading 138
Review Questions 139
8 Clinical Diagnostic Decision Support Systems (CDDSSs) 141
8.1 Introduction 142
8.1.1 Definition 142
8.1.2 Questions you should ask 143
8.2 Understanding the methodology used by CDDSSs 143
8.2.1 Logic 144
8.2.2 List matching 145
8.2.3 Probabilities (Bayes' rule) 145
8.2.4 Knowledge-based systems incorporating symbolic reasoning (syntactical systems) 146
8.2.5 Bayesian belief networks 147
8.2.6 Neural networks 147
8.3 Sources of uncertainty or inaccuracies 147
8.4 Evaluation of the performance of CDDSSs 148
8.4.1 Which is the best method to measure the performance of a CDDSS? 148
8.4.2 Alternative desirable indicators of performance using accuracy 149
8.5 Veterinary diagnostic decision support systems 149
8.5.1 A decision support algorithm for individual cow infertility 149
8.5.2 Consultant 150
8.5.3 Vetstream Canis 154
8.5.4 PROVIDES (Problem Orientated Veterinary Information and Decision System) 154
8.5.5 Bovid 157
8.5.6 EqWise 161
8.5.7 Cattle Disease Diagnostic System (CaDDiS) 162
8.5.8 Application of probability techniques to the objective interpretation of veterinary clinical biochemical data 163
8.6 Sources of information of the CDDSSs described in this chapter 165
Further reading 167
Review questions 168
9 Decision Analysis, Models and Economics as Evidence 170
9.1 Introduction 171
9.2 Decision analysis 171
9.2.1 Methods for clinical decision making 171
9.2.2 Situations in which decision analysis may be helpful 172
9.2.3 The five steps in decision analysis 172
9.2.4 Disadvantages of decision analysis 173
9.3 Decision trees 173
9.3.1 Utilities 174
9.3.2 Solving the decision tree 174
9.3.3 Sensitivity analysis 174
9.3.4 Missing options 174
9.3.5 Helping owners decide 175
9.3.6 Obtaining utility values from clients and owners 176
9.3.7 Decision analysis tree for therapeutic decisions 177
9.3.8 Decision analysis tree for economic decisions 177
9.3.9 Decision analysis tree of diagnostic tests 179
9.3.10 Pay-off tables 182
9.3.11 User checklist for clinical decision analysis 185
9.4 Testing and treating thresholds 185
9.4.1 General properties of testing and treating thresholds 186
9.5 Modelling 187
9.5.1 Modelling herd infection dynamics 188
9.5.2 Modelling and the control of foot and mouth disease 190
9.5.3 Modelling Staphylococcus aureus infection in a herd 191
9.5.4 User guide to models 191
9.6 Economic analysis 192
9.6.1 Partial budgets and cost-benefit analysis 192
9.6.2 User guide to economic analysis 194
9.7 Medline search functions 194
References and further reading 194
Review questions 196
10 EBVM: Education and Future Needs 198
10.1 EBM in medical education 199
10.2 Resources for the practice of EBM 199
10.2.1 Critically appraised topics (CATs) 199
10.2.2 High quality systematic reviews 199
10.2.3 The Cochrane Library 200
10.2.4 Secondary journals (e.g. EBM) 201
10.3 EBM in veterinary education 201
10.3.1 Evidence-based veterinary toolkit 201
10.3.2 Finding out what is in the literature and what is not in the literature 201
10.4 What resources do we need for the practice of EBVM? 201
10.5 Clinical (EBVM) audits in veterinary practice 202
10.5.1 What is a clinical audit? 202
10.5.2 Why do we need a clinical audit? 202
10.5.3 What has a clinical audit got to do with EBVM? 202
10.5.4 How do we carry out an EBVM audit? 202
10.5.5 Clinical audits and the future 203
10.6 Other future developments 203
References and further reading 204
Glossary of Terms Used in EBVM 206
Bibliography 217
Answers to Review Questions 220
Index 222

Rezensionen

"It addresses an emerging topic, which has 'been around' in
human medicine for several years. The topic has yet to be taken up
widely in veterinary medicine."

"I would suspect that most US veterinary school libraries
would purchase a copy as well as the obvious UK market."

Mike Thrusfield, Royal (Dick) School of Veterinary
Medicine, Edinburgh.

"An overview of this topic is timely, especially as it is
forming part of the undergraduate curriculum."

John Innes, Orthopaedic Specialist, University of
Bristol.

"An interesting and understandable presentation introducing the
relatively novel concept of EBVM."

Lab Animal News (US)

Produkt-Details

• Erscheint lt. Verlag: 15.4.2008
• Sprache: englisch
• Themenwelt: Medizin / Pharmazie
• Themenwelt: Veterinärmedizin
• Schlagworte: animals • application • appropriate • Book • Diagnosis • evidencebased • lifelong • Medicine • medicine ebvm • Methodology • Patient • Practice • practise • Range • Skills • Tiermedizin • Toolkit • User • Veterinärmedizin • Veterinärmedizin • Veterinary • Veterinary Medicine
• ISBN-10: 0-470-68054-7 / 0470680547
• ISBN-13: 978-0-470-68054-4 / 9780470680544