Research Methodology Sohail Bajammal, MBChB, MSc, FRCS(C), PhD(c) [email protected] Assistant Professor, Umm Al Qura University Consultant Orthopaedic Surgeon, Al-Noor Specialist Hospital
May 20, 2015
Research Methodology
Sohail Bajammal, MBChB, MSc, FRCS(C), PhD(c)[email protected]
Assistant Professor, Umm Al Qura UniversityConsultant Orthopaedic Surgeon, Al-Noor Specialist Hospital
What got me into EBM….
What is a double blind study?
Two orthopaedic surgeonsreading an ECG
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EBM is not new…….
على “ والمقاييس البحث في نرقى ثمالمقدمات انتقاد مع والترتيب التدريجفي غرضنا ونجعل النتائج في والتحفظاستعمال ونتصفحه نستقرئه ما جميع
ما سائر في ونتحرى الهوى اتباع ال العدلمع الميل ال الحق طلب وننتقده نميزه
بن ”اآلراء الحسنالهيثم
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Objectives
• What is research?
• Why do we need to do research?
• What is the difference between research methodology and EBM?
• What are the types of research?
• How to do research?
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What is research?
Systematic investigation towards increasing the sum of knowledge
(Chambers 20th Century Dictionary)
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EconomicLegal
Therapy
Perspectives of Research
Basic Science Social
Diagnosis
Prognosis
Clinical
Health Problem“Trauma”
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Why do we need to do research?“locally”
• Ethnic• Psychosocial• Cultural• Economic
Different
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Research Methodologyvs
Evidence-Based Medicine
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Research
Doing
Using
Research Methodology
EBM
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EBM
Clinical Circumstances
Research Evidence
Patients’ Preferences
Clinical Expertise
Haynes et al. BMJ 2002;324:1350
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5As of EBM
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Is this a good question?
What is the best treatment of back pain?
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Asking a good question (PICO)!
• Population• Intervention• Control• Outcome
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Is this a good question?
• In adult patients younger than 50 years old with acute low back pain (< 6 weeks), does bedrest reduce the risk of recurrence of pain within one year compared with physiotherapy?
• P: Adult patients <50yr with acute LBP• I: Bedrest• C: Physiotherapy• O: Recurrence of pain within one year
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5As of EBM
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5S Hierarchy of Evidence
RCTs, Cohort, Case control, Case series
Expert Opinion: Classical Textbooks
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Primary Sources
• Original articles• Using: PubMed, OVID• You have to retrieve and appraise the articles• Levels (strength) of evidence
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Levels of Evidence
http://library.downstate.edu/EBM2/2100.htm
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It’s time consuming
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5S Hierarchy of Evidence
RCTs, Cohort, Case control, Case series
Systematic Reviews
Critically-Appraised Journal Articles & Abstracts
Evidence-Based Guidelines & Textbooks
Computerized Decision Support
Expert Opinion: Classical Textbooks
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To practice EBM, we need all four
Clinical Circumstances
Research Evidence
Patients’ Preferences
Clinical Expertise
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Research Methodology
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Research Methodology
Planning
Conducting
Publishing
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Research Question
Truth in the Universe
Target Population
Phenomena of interest
Study Plan
Truth in the Study
Intended Sample
Intended variables
Actual Study
Findings in the Study
Actual subjects
Actual measurements
From Hulley et al. Designing Clinical Research. LWW
Design Implement
InferInfer
ErrorsErrors
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• Random Errors: mistakes by chance
• Systematic Errors: bias
Errors in Research Methodology
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• Assemble a research team• Ask a good research question• Do a literature search• Choose the proper study design• Determine the sampling design• Get ethical approval
Research Planning
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Research Team
• Research is not a one man/woman show
• You need a team at every step
• Ask a research methodologist & a biostatistician EARLY
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Good Research Question (FINER)
• Feasible
• Interesting
• Novel
• Ethical
• Relevant
PICO
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Sampling
The UniverseStudy
PopulationStudy
Sample
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Bad Sampling
The UniverseStudy PopulationStudy
Sample
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Sample Size
• You need to have enough research participants (patients) to show a difference
• Depends on:– The incidence of the outcomes you are assessing
in each group– The prevalence of the disease
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Sample Size
• Compare applying pressure with no pressure to control active bleeding?
• Compare antibiotics with no antibiotics for bad open fractures to reduce the risk of infection?
• Compare antibiotics with no antibiotics for pneumonia to reduce septic shock?
• Compare LMWH with Unfractionated heparin to reduce the risk of DVT after TKA?
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Types of Research
Quantitative Qualitative
Mixed-Methods
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Quantitative Research
• Descriptive:– Case report– Case series– Cross-sectional
• Analytical:– Observational: cohort studies, case-control– Experimental: randomized trials
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Descriptive Studies
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Case Report
• A descriptive study of one patient
• Detailed profile of a “rare” presentation or treatment
• Helpful in developing hypothesis to be tested later using analytic study
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Case Series
• A descriptive study of multiple patients
• “Rare” phenomenon occurring multiple times
• Detailed profile of patients’ presentation and outcome
• Helpful in developing hypothesis
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Cross-Sectional Studies
• Descriptive “Survey”
• One to one questionnaire, mail, telephone, online
• Attention to details:– Sampling– Construction of the questions– Construction of the responses
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Analytical Studies
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Case-Control Studies
Cases(e.g., Lung Cancer)
Control(e.g., NO Lung
Cancer)
GO BACK IN TIME
GO BACK IN TIME
Ask patientsRead files
Shisha Smokers
NOT Shisha Smokers
Shisha Smokers
NOT Shisha Smokers
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Case-Control Study
Lung Cancer
Yes No
Shisha Smoking
Yes
No
ODDS RATIO
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Problems with Case-Control Studies
• Looking back in time (retrospective)
• Recall bias
• Measurement bias
• You may miss important risk factors
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Prospective Cohort
Shisha Smokers
NOT Shisha Smokers
F/U
F/U
Lung Cancer
No Lung Cancer
Lung Cancer
No Lung Cancer
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Cohort Study
Lung Cancer
Yes No
Shisha Smoking
Yes
No
RELATIVE RISK
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Cohort Study
• Prospective or Retrospective
• Drawbacks:– Large number of patients– Follow them up for long time
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Randomized Controlled Trial (RCT)
Patients with MI RANDOM
Drug A
Drug B
F/U
F/U
Outcomes
Outcomes
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Why RCT is the highest level of evidence?
• Randomization: balance known and unknown prognostic factors
• Blinding:– Patients– Researchers– Outcome assessors
• Aim for complete follow-up
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• Ask for help Research assistants
• Monitor the conduct of the study–No deviation–Patients safety–Complete data
Conducting Research
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• During the planning phase: who will do what?
• Oral & written
• Pick your audience (pick a Journal)
• Write your paper with the Journal you picked in mind
• Don’t give up, you will get rejected
Publishing Research
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Take Home Messages
• Research is not a one man/woman show– You need a team to do good research
• Research is a science– You need to learn how to do it
• Research is like riding a bicycle– You need to practice
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Take Home Messages
• Research needs planning– If you fail to plan, you plan to fail
• Not all of us need to do research– But all of us should practice EBM
• Never ever give up– You will get rejected
GCC EBHC
http://eapps.ngha.med.sa/ebm/
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Objectives
• What is research?• Why do we need to do research?• What is the difference between research and
EBM?• What are the types of research?• How to do research?