Identifying the study design is important in ensuring critical appraisal is carried out in the right manner as different study designs require different aspects of the study to be appraised.
The most common types of study designs are:
• Qualitative studies:
Qualitative studies explore and understand people's beliefs, experiences, attitudes, behaviour and interactions. They generate non-numerical data.
Examples of qualitative studies:
» Passive observation
» Participant observation
» In depth interview
» Focus group
• Quantitative studies
Quantitative studies generate numerical data.
Examples of quantitative studies:
» Randomized Controlled Trial (RCT)
» Systematic review
» Case report
» Case series
» Case control study
» Cohort study
Spotting the Study Design
The type of study can generally be worked at by looking at three issues:
Q1. What was the aim of the study?
Q2. If analytic, was the intervention randomly allocated?
Q3. If observational, when were the outcomes determined?