Table 4.

Various Study Designs for Evaluating AE.

Reports	Accuracy	Generalizability	Special attributes
Case reports	+	Poor	Highlights rare sensational attributes
Case series	++	Poor	Institutional bias
Clinical trials	+++++	++	Small samples Expert care Sicker patients not represented AE are usually lower
Clinical registries	++++	+++++	Often expensive Specific purposes Access for analysis is limited selection bias
Passive surveillance	+++	+++++	Inexpensive Publicly available Cross-sectional snapshot Reporting may not be accurate