Use of larger versus smaller drug-safety databases before regulatory approval: the trade-offs.

Although efforts to revamp the drug-safety system have been directed at strengthening postmarketing surveillance, strategies for the preapproval stage may be useful. One strategy would be to require larger sample sizes in preapproval safety databases. To evaluate the potential benefits and costs of this approach, we developed a hypothetical model to estimate the expected incremental number of adverse drug events that could be avoided in a postapproval population. We found that the potential to limit adverse events can be an important consideration in sample-size determinations for preapproval trials. Requiring larger preapproval databases could be a cost-effective means of reducing adverse events in postapproval populations.