Types of epidemiological studies

1. Case Control & Cohort
Observational Studies
Edited by : Dr. Nermin Osman
Assistant lecturer of Medical Statistic
Medical Research Institute, Alexandria University
United Nations System Staff College Intern-UNITAR

2. Research designs
Secondary
Research
Designs
Systematic
Review/Meta
analysis
Primary
Research
Designs
Descriptive
Cross-
sectional
(survey)
Qualitative Case Report Case Series
Analytical
Experimental
RCT
Controlled
Clinical Trial
Observational
Cohort
Case-control
3

3. Levels of Evidence
Systemat
ic Review
with MA
Systematic
Review
Double-blind RCT
RCT without blinding
Non-Randomised Controlled
Trial
Cohort Study
Case-Control Study
Cross-sectional Survey
Case Report / Case Series
Expert Opinion

15. Figure 1.Representation of the reference time points for
exposure data and outcomes of interest in cohort studies.

23. Confounders

28. Odds ratio Relative risk