- The case control study is most appropriate for investigating uncommon diseases because it starts with identifying cases that already have the disease and compares them to controls without the disease.
- This design is efficient and cost-effective for rare conditions, as it requires fewer subjects and retrospective data collection.
- In contrast, prospective cohort studies or randomized controlled trials require large sample sizes and long follow-up, making them impractical for uncommon diseases.

Reference: Gordis, L. *Epidemiology*, 5th Edition, Chapter 4, Page 75-80