Table 1.
Study designs6
| Type of study | Description | Pros | Cons |
|---|---|---|---|
| Case series | Subjects with interesting outcomes are presented | -Cheap | -Selection bias |
| -Fast | -No control group | ||
| Cross-sectional | Simultaneous assessment of exposure and outcome in a group | -Useful in studying prevalence outcomes | -No temporal relationship between exposures and |
| Case-control | Subjects selected based on outcome and then exposure is assessed | -Overcomes temporal delays-May only require small sample size | -Selection and recall bias |
| -Temporal relationship may not be clear | |||
| Cohort | Subjects with and without exposure are followed | -Feasible when randomization of exposure is not possible | -Critically depends on follow-up |
| -Classification and measurement accuracy | |||
| RCT | Exposure is randomly determined | -Least susceptible to bias | -Feasibility |
| -Generalizability |