Table 3.

Strengths and weaknesses of automated prescription databases

Strengths	Weaknesses
Large sample size	Uncertain diagnosis
Relatively inexpensive	Lack of information on confounding variables (e.g. smoking status)
Relatively complete data	Lack of information on over-the-counter/nonprescription items
Population/‘real world’ based	Unstable population due to economic factors
No recall and interviewer bias	Only include medical illnesses severe enough to come to medical attention
	Results may not be generalizable to the wider population