FRCEM FINAL: Critical Appraisal Made Easy e-Book

By Moussa Issa

This small compilation provides prospective candidates a glossary of medical terms used in Evidence based-Medicine and a step-by-step approach to how critically appraise articles published in medical journals and guidelines on how to search for reports.

The purpose of critical appraisal is to help the health care professional to read resea

• Language: English
• Publisher: FRCEM Exam Bookstore Ltd
• Release date: Feb 23, 2019
• ISBN: 9781916029668

Book preview

CRITICAL

APPRAISAL

MADE EASY

EVIDENCE-BASED MEDICINE

Author: Moussa Issa

Editor:

Muhammad Fayyaz Alam Janjua

MBBS MRCP (UK) MRCPI BSc

Medical Registrar

Copyright © 2019, FRCEM Exam Bookstore Limited.

Distributed by FRCEM Exam Bookstore Ltd

UK Store: www.frcemexambookstore.co.uk

Indian store: www.frcemexambookstoreindia.co.uk

WhatsApp: [phone]

CRITICAL

APPRAISAL

MADE EASY

EVIDENCE-BASED MEDICINE

Author: Moussa Issa

Editor:

Muhammad Fayyaz Alam Janjua

MBBS MRCP (UK) MRCPI BSc

Medical Registrar

Copyright © 2019, FRCEM Exam Bookstore Limited.

Distributed by FRCEM Exam Bookstore Ltd

UK Store: www.frcemexambookstore.co.uk

Indian store: www.frcemexambookstoreindia.co.uk

WhatsApp: [phone]

DISCLAIMER

TERMS OF USE

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You may use the work for your own noncommercial and personal use to prepare your FRCEM Critical Appraisal exam; any other use of the work is strictly prohibited.

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This material has been compiled in a user-friendly format, with the intention of helping prospective candidates to the FRCEM Critical Appraisal exam.

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Copyright © 2018 PGB Group

PREFACE

Nowadays, the amount of health care research undertaken has grown significantly, especially over the past decades. Each year, hundreds of published Medical journals contain thousands of reports of research studies.

Surprisingly, it is an unfortunate fact that not all published research is good quality. The health care professional has to search the literature for information on factors affecting patient care and/or service delivery.

These articles will vary in terms of quality, comprehensibility and relevance to practice. Some studies, although well researched, will have limitations due to aspects of research design.

This small compilation provides prospective candidates a glossary of medical terms used in Evidence Based-Medicine and a step-by-step approach on how to critically appraise articles published in Medical journals and guidelines on how to search for reports.

The purpose of critical appraisal is to help the health care professional to read research studies objectively by identifying valid and irrelevant points, the strengths and weaknesses and the usefulness of a report with its limitations.

Critical reading of research reports increases the practitioner's understanding of the research process. Doctors undertaking their own studies will eventually benefit from developing their critical evaluation skills by appraising their own projects and enhance their skills at all stages of the study process from project design to writing the final report.

Readers will be guided through the processes and provided with information on the factors that can affect the quality of the literature search and the study articles found. Exercises and past exams are inserted to reinforce the candidate's understanding of the text.

Dr Muhammad Fayyaz Alam Janjua

MBBS MRCP (UK) MRCPI Bsc

Medical Registrar

ACKNOWLEDGEMENTS

This journey would not have been possible without the support of my family, and friends. To all of you, thank you for encouraging me in all of my pursuits and inspiring me to follow my dreams.

I am especially grateful to Marlene Issa, my best friend, wife and private advisor, for all her emotional supports. I always knew that she believes in me and wanted the best for our family. Thank you for always being around when needed;

Thank you to my mother, Clementine Tshimpusu, to my wonderful children Tatiana Issa, Kevin Issa and Ryan Issa.

I must thank all of the colleagues whom I have worked with over the last three years for showing me what it means to be a dedicated, each in their own unique way. Each of you has given of your time, energy, and expertise and I am richer for it:

Stephanie Andor, Raoul Maag, Humayra Garda, James Visser, Joe Conway, Loay Shalha, Sayed Ramadan, Muhammad Amjad, Faizan Alam, Ahmed Al Rasheed Ahmed,  Rehmat Jan, Nasir Mahmood, Abdul Sattar, Fiona Dunne, Ann Campion, Theresa O’Donnell, David Carroll, Aine Williams, DC Swain, Carmel Cox, Maria Kenny, Norma Bergin, Amanda Wickham, Sinead Docherty, Denise Gavin, Margaret Hynes, Katherine Lynch, Ann Walsh, Elaine Neary, Patricia Treacy, Mary Gray, Deirdre Keane, Mary Claire Kelly, Hellen Cullinane, Leigh McMorran, Sinead Crotty, Orla Delahunty, Michael Tierney, Lorraine Kelly, Ciara Grogan, Glenn Allender, Elaine Wall, Martina Brennan, Anita Grace, Triona McKee, Joy Moore, Kerrie Stapleton, Deirdre O’Riordan, Sinead Fox, Ann Cummins , Louise Rafter, Jason Brennan, Marta Brezinska, Bernie Cahill, Anne Hunt and Lorraine Maher.

A particular thanks to Muhammad Fayyaz Alam Janjua for editing a large part of this book.

Dr Moussa Issa

MBChB MRCEM

Senior ED Registrar

TABLE OF CONTENTS

I. BASIC OF EVIDENCE BASED MEDICINE

I. Introduction to Critical Appraisal

1. PROS OF CRITICAL APPRAISAL IN PRACTICE

2. CONS OF CRITICAL APPRAISAL IN PRACTICE

II. Fifty Best Concepts & Definitions

1. ALLOCATION CONCEALMENT

2. ABSOLUTE RISK REDUCTION

3. ACCURACY

4. BLINDING

5. CHANCE, BIAS AND CONFOUNDING

6. CLINICAL PREDICTION RULE

7. CONSORT STATEMENT

8. CONVENIENCE SAMPLING

9. COX PROPORTIONAL-HAZARD MODEL

10. EFFECT MODELS

11. EFFICACY AND EFFECTIVENESS

12. ENDPOINTS OR OUTCOMES

13. FACTORIAL DESIGN

14. GRADE OF RECOMMENDATION

15. HETEROGENEITY

16. HYPOTHESIS

17. INTENTION TO TREAT ANALYSIS

18. INTEROBSERVER VARIABILITY

19. INTRAOBSERVER VARIABILITY

20. JADAD

21. HAZARD (OR HAZARD RATE)

22. HAZARD RATIO

23. KAPLAN-MEIER CURVE

24. KAPPA

25. LEVEL OF EVIDENCE

26. LIKELIHOOD RATIOS

27. METAREGRESSION

28. MULTIVARIATE ANALYSIS

29. ODD RATIO

30. PRE-TEST ODDS

31. POST-TEST ODDS

32. PRE-TEST PROBABILITY

33. POST-TEST PROBABILITY

34. POWER

35. PRAGMATIC & EXPLANATORY RESEARCH

36. PRECISION

37. RANDOMISATION

38. RECEIVER OPERATOR CURVE (ROC)

39. REGRESSION

40. RELATIVE RISK RATIO

41. RELIABILITY

42. SENSITIVITY (TRUE POSITIVES)

43. SENSITIVITY ANALYSIS

44. SPECIFICITY (TRUE NEGATIVES)

45. SURVIVAL ANALYSIS

46. SYSTEMATIC REVIEW

47. TYPE 1 ERROR

48. TYPE 2 ERROR

49. VALIDATION AND DERIVATION PROCEDURES

50. VALIDITY AND GENERALISABILITY

III. Evidence Hierarchy

HIERARCHIES OF EVIDENCE

LEVELS OF EVIDENCE GRADE - EVIDENCE GRADES

1. CASE SERIES & CASE REPORTS

2. CROSS SECTIONAL STUDY

3. CASE CONTROL STUDIES

4. COHORT STUDIES

5. RANDOMISED CONTROLLED STUDIES

6. SYSTEMATIC REVIEW

7. META-ANALYSIS

IV. Study Design

1. QUANTITATIVE STUDIES

2. QUALITATIVE STUDIES

3. OBSERVATIONAL STUDIES

4. RANDOMISED CONTROLLED STUDIES

5. CROSSOVER STUDIES

6. N-OF-1 TRIALS

7. NON-INFERIORITY STUDIES

8. INTENTION-TO-TREAT ANALYSIS

9. PER-PROTOCOL ANALYSIS

10. LAST OBSERVATION CARRIED FORWARD ANALYSIS

V. Randomisation in Clinical Trial

1. RANDOM NUMBER GENERATION

2. RANDOMISATION METHODS

3. CONCEALED ALLOCATION

VI. Methods of Sampling In Research

1. SIMPLE RANDOM SAMPLING

2. SYSTEMATIC SAMPLING

3. STRATIFIED SAMPLING

4. CLUSTER SAMPLING

5. CONVENIENCE SAMPLING

VII. Statistics

1. HYPOTHESIS TESTING (THE P-VALUE)

2. ESTIMATION (CONFIDENCE INTERVALS)

3. TYPE I & TYPE II STATISTICAL ERRORS

4. POWER

5. EXPERIMENTAL EVENT RATE (EER)

6. CONTROL EVENT RATE (CER)

7. ABSOLUTE RISK

8. RELATIVE RISK

9. ODDS RATIO

10. RISK REDUCTION

11. NUMBER NEEDED TO TREAT (NNT)

12. NUMBER NEEDED TO HARM (NNH)

13. KAPPA

VIII. Normal & Skewed Distributions

I. TYPES OF DATA IN MEDICAL RESEARCH

II. NORMAL OR GAUSSIAN DISTRIBUTION

III. SKEWED DISTRIBUTION

IV. MEASURES OF CENTRAL TENDENCY

V. TYPES OF OUTCOMES IN CLINICAL RESEARCH

II. CRITICAL APPRAISAL APPROACH

1. How to Write a Good Abstract for a Scientific Paper

1. INTRODUCTION OR BACKGROUND

2. METHODS

3. RESULTS

4. DISCUSSIONS OR CONCLUSIONS

5. MISCELLANEOUS OBSERVATIONS

6. CONSORT STATEMENT

2. Appraising Randomised Controlled Trials

12 QUESTIONS TO HELP YOU MAKE SENSE OF A TRIAL

SECTION A: ARE THE RESULTS OF THE STUDY VALID?

SECTION B: WHAT ARE THE RESULTS?

SECTION C: WILL THE RESULTS HELP LOCALLY?

3. What is Therapeutic study?

1. SELECTION AND ALLOCATION OF STUDY PARTICIPANTS

2. RANDOMISATION

3. ALLOCATION CONCEALMENT

4. BLINDING

5. INTENTION TO TREAT ANALYSIS

6. FOLLOW-UP

7. OUTCOME MEASURES

8. MEASURES OF EFFECTIVENESS

4. Appraising Therapeutic Studies

SECTION A. DOES THIS STUDY ADDRESS A CLEAR QUESTION?

SECTION B. ARE THE RESULTS OF THIS SINGLE TRIAL VALID?

SECTION C. WHAT WERE THE RESULTS?

SECTION D. CAN I APPLY THESE VALID, IMPORTANT RESULTS TO MY PATIENT?

5. What is Diagnostic Test study?

1. TERMS USED IN REPORTING DIAGNOSTIC TEST DATA

2. HOW ARE THE TERMS USED?

3. LIKELIHOOD RATIOS

4. THE REFERENCE STANDARD (GOLD STANDARD)

6. Appraising Diagnostic Test Studies

SECTION A. HOW DO WE ASSESS IF A DIAGNOSTIC TEST STUDY IS VALID?

SECTION B. HOW DO WE ASSESS THE RESULTS OF THE TEST?

SECTION C. HOW TO APPLY THE DIAGNOSTIC TEST TO A SPECIFIC PATIENT

THE ROC CURVE

7. Appraising a Systematic Review

TEN QUESTIONS TO HELP YOU MAKE SENSE OF A SYSTEMATIC REVIEW

8. Appraising Cohort Studies

12 QUESTIONS TO HELP YOU MAKE SENSE OF COHORT STUDY

9. Appraising Case Control Studies

11 QUESTIONS TO HELP YOU MAKE SENSE OF CASE CONTROL STUDY

10. Appraising Qualitative Research

10 QUESTIONS TO HELP YOU MAKE SENSE OF QUALITATIVE RESEARCH

11. Appraising Economic Evaluations

12 QUESTIONS TO HELP YOU MAKE SENSE OF ECONOMIC EVALUATIONS

III. COMMON ASKED QUESTIONS

QUESTIONS 1

QUESTION 2

QUESTION 3

INDEX

FRCEM EXAMS BOOK COLLECTION

I. BASIC OF EVIDENCE BASED MEDICINE

I. Introduction to Critical Appraisal

Evidence based clinical practice is an approach to decision making in which the clinician uses the best evidence available, in consultation with the patient, to decide the option which suits the patient best.

To determine what the best evidence is, we need critical appraisal skills that will help us to understand the methods and results of research and to assess the quality of the research.

Critical appraisal is the process of systematically examining research evidence to assess its validity, results and relevance before using it to inform a decision. Critical appraisal is an essential part of evidence-based clinical practice that includes the process of systematically finding, appraising and acting on evidence of effectiveness. Critical appraisal allows us to make sense of research evidence and thus begins to close the gap between research and practice.

Randomised controlled trials can minimise bias and use the most appropriate design for studying the effectiveness of a specific intervention or treatment.

Systematic reviews are particularly useful because they usually contain an explicit statement of the objectives, materials and methods, and should be conducted according to explicit and reproducible methodology.

Randomised controlled trials and systematic reviews are not automatically of good quality and should be appraised critically. Critical appraisal is one step in the process of evidence-based clinical practice.

Most research is not perfect, and critical appraisal is not an exact science it will not give us the right answer.