Type of studies

Type of Clinical literature

TRIAL Phases

Systematic Review


There is debate about the best practice for meta-analysis, however. there are five common steps.


Free software for meta-analysis:

Narrative Review

Steps for Conducting a Narrative Literature Review: 

Step 1: Conduct a Search. The first step in writing a narrative overview is to perform a preliminary search of the literature.

Step 2: Identify Keywords.

Step 3: Review Abstracts and Articles.

Step 4: Document Results.

Randomized clinical trials

Cohort studies

Case-Control sTUDIES



When to use case-control design:

Before-after studies

Cross-sectional studies

Case series/REPORT

A case study, also known as a case report, is an in depth or intensive study of a single individual or specific group, while a case series is a grouping of similar case studies / case reports together. They are generally descriptive studies based on qualitative data e.g. observations, interviews, questionnaires, diaries, personal notes or clinical notes.

There are many classifications for case series: (El-Gilany AH. What is case series?. Asp Biomed Clin Case Rep. 2018 Aug 17;1(1):10-15.)

A. Informal vs. Formal Case Series: 

B. Consecutive vs. Non-Consecutive Case Series: 

C. Exposure or Outcome-Based Sampling: 

Questions/elements to be included in the presentation of the cases (Abdel-Hady El-Gilany.2018):