1. Khairil Anuar Md. Isa Faculty of Health Sciences, UiTM

2.  Observe at one particular time or over a period  Exposure & outcome measured at the same time  Also known as prevalence study  Information obtained from the subjects only once

3. Population Sampled Unexposed Exposed No disease Disease

4.  Strength ◦ Very quick and inexpensive to implement ◦ Useful for determining prevalence ◦ Appropriate for diagnostic test for validity

5.  Weakness ◦ Difficulty in establishing links of causal effect ◦ Impractical for rare outcome