1. Statistics & research
methods for clinicians
Ramez Reda Moustafa

2. Objectives
Introduce statistical and research methods
commonly used in the medical sciences
Break the psychological barrier
Introduce the basics of scientific writing
and publishing in medicine

3. What this course is not
A comprehensive course on statistics
A series of lectures

4. What I am not
A statistician

5. TYPES OF DATA
Categorical - Nominal
 Yes/No
 Male/Female
 Red/White/Black
Ordinal
 mild/moderate/severe
 Low/normal/high

6. TYPES OF DATA
Continuous (quantitative, numerical)
 Age
 Blood pressure
 ESR

7. What type?
Glasgow coma scale
Modified Rankin scale
Hb
Splenomegaly
Fever
Dysphasia

8. Samples
Related or independent, that is the
question.

9. Categorical
Ordinal or Non-Normal
Continuous
Normal Continuous
One sample Chi-squared test Kolmogorov-Smirnov test one sample t-test
Two samples independent
Chi-squared or Fisher's exact
test
Mann-Whitney U test Student t-test
paired McNemar's test Wlcoxon Signed Rank test Paired t-test
Multiple samples
(k>2)
independent Chi-squared test Kruskal-Wallis test ANOVA
related Cochran-Q test Friedman test repeated measures ANOVA

10. Variance
N=1 studies
100% studies
CI
SD
SEM

11. Sample size
The “N”
Pilot studies

12. Summarizing data
The Mean
The Median
Frequency/proportion

13. Answering questions
1. Asking the question
2. What is my data
3. The method
4. Hypothesis testing or not

14. Collecting data
Lab book
forms
Source data
Computer
 Excel
 SPSS
The table(s)
Master sheet? What master sheet?

15. Collecting data
Too many variables
Too few variables

16. Looking through your data
Tables
Graphs
Descriptive stats