Case series and case reports are time-efficient and resource-intensive methods that utilize existing clinical data to recognize new diseases and generate hypotheses. However, they may lack representativeness and do not include a comparison group, which can introduce systematic errors. Despite these disadvantages, they serve as a foundation for further analytic studies, such as case-control studies.

1. Case Series & Case Reports
Advantages Disadvantages
Time-efficient, less resource-
intensive
Uses available clinical data
Recognizes new diseases
Rapid hypothesis generation
Basis for analytic study

2. Case Series & Case Reports
Advantages Disadvantages
Time-efficient, less resource-
intensive
Cases may not be representative
Uses available clinical data No comparison group or underlying
population represented
Recognizes new diseases Open to systematic errors
Rapid hypothesis generation
Basis for analytic study
Can launch a case-control study