In 1998, a multidisciplinary team of investigators initiated RADAR (Research
on Adverse Drug events And Reports), a clinically based postmarketing surveillance
program that systematically investigates and disseminates information describing
serious and previously unrecognized adverse drug and device reactions (ADRs).
To describe the structure, operations, and preliminary findings from
the RADAR project and related dissemination efforts by pharmaceutical suppliers
and the US Food and Drug Administration (FDA).
After identifying a serious and unexpected clinical event suitable for
further investigation, RADAR collaborators postulated clinical hypotheses
and derived case series and incidence estimates from physician queries, published
and unpublished clinical trials, published case reports, FDA databases, and
manufacturer sales figures.
RADAR investigators identified 16 types of serious ADRs among 1699 patients,
of whom 169 (10%) died as a result of the reaction. Initial cases were identified
by 7 RADAR investigators, 4 collaborating physicians, 2 attorneys, and by
reviewing 3 published reports. Additional sources included queries of occupational
health programs and medical directors of interventional cardiology laboratories
(3 types of ADRs), published manuscripts and clinical trials (11 types of
ADRs), review of medical records at a RADAR site (2 types of ADRs), unpublished
clinical trial reports (3 types of ADRs), and reports from attorneys, family
members, or patients (4 types of ADRs). Incidence estimates, ranging from
0.4% to 33%, were derived from 5 clinical trial reports, 2 physician queries,
and 2 observational databases. Laboratory support for hypotheses included
identification of 3 neutralizing antibodies and 3 histopathological findings.
ADR reports were disseminated as 8 revised package inserts, 7 “dear
doctor” letters, and 9 peer-reviewed articles.
A new, clinically based, hypothesis-driven approach to postmarketing
surveillance may supplement existing regulatory surveillance systems and improve