Diagrammatic Summary of1. Research Methodology2. Ethical Considerations

3. Statistical Considerations“The Journey Towards Your Research Project:

Writing Research Proposal”

Sohail Bajammal, MBChB, MSc, FRCS(C), PhD(c)Assistant Professor of Orthopaedics, Umm Al-Qura University

Director of CME & Research Administration, King Abdullah Medical City Makkah

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Research

Doing

Using

Research Methodology

EBM

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EBM (evidence-based clinical practice)

Clinical Circumstances

Research Evidence

Patients’ Preferences

Clinical Expertise

Haynes et al. BMJ 2002;324:1350@bajammal

EconomicLegal

Therapy

Perspectives of ResearchThink Broad!

Basic Science Social

Diagnosis

Prognosis

Clinical

Health Problem“Trauma”

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Research Methodology Phases

Planning

Conducting

Publishing

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Research Problem

Research Question

Research Design

Data Collection

Data Analysis

Research Dissemination@bajammal

Methodological, Ethical &

Statistical Considerations at Each Stage

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

Physiology of ResearchPatho

Internal ValidityExternal Validity@bajammal

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Sampling

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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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Prospective Cohort

Shisha Smokers

NOT Shisha Smokers

Follow Up

Follow Up

Lung Cancer

No Lung Cancer

Lung Cancer

No Lung Cancer

Methodologically sound, but Unethical

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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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bioethics.kacst.edu.sa

NationalityGender

Stage I, II, III & IV cancer

Pulse(0 is dead)

Temperature(0 is not zero)

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Measures of Central Tendency

Type of VariableBest measure of

central tendency

Nominal Mode

Ordinal Median

Interval/ratio(not skewed)

Mean

Interval/ratio(skewed)

Median

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68 % of observations

95 % of observations

99.7 % of observations

STANDARD DEVIATIONS

-3 -2 -1 0 1 2 3

MEAN

Courtesy of Prof. Hassan Baaqeel

Normal Distribution

1 SD

2 SD

3 D

Parametric

Tests

Choice of Statistical Tests

GoalInterval/Ratio(normal distribution)

1. Ordinal2. Interval/Ratio

(skewed)Nominal

Comparison of 2 unrelated groups Unpaired t-test Mann-Whitney U

Chi-square TestComparison of >2 unrelated ANOVA Kruskal-Wallis H

Comparison of 2 related groups Paired t-test Wilcoxon

Binomial Sign TestComparison of >2 related groups

Repeated measures ANOVA Friedman

Correlation Pearson’s Spearman’s rho Chi-square Test

Parametric Tests

Non-Parametric Tests

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Hypothesis Testing (α & β errors)

Results in the Study Sample

Truth in the Population

Association Between Predictor & Outcome

No Association Between Predictor & Outcome

Reject null hypothesis Correct Type I error (α)

Fail to reject null hypothesis Type II error (β) Correct

Null Hypothesis: No association between predictor & outcome

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