Reporting of adverse events to MedWatch.

Trends in the reporting of serious adverse events directly to FDA between 1992 and 1994 and the quality of reports before and after the June 1993 launching of MedWatch were studied. Computerized data were used to assess changes between 1992 and 1994 in the proportion of adverse-event reports to FDA classified as serious. To evaluate the quality of reports, every third report received during April 1993 (sample size, 254) and April 1994 (263) was evaluated for 21 variables and to determine whether the event was serious. For the first analysis, a serious adverse event was defined as one that resulted in death, hospitalization or prolongation of hospitalization, or disability; for the second, the outcome of a threat to life was also included. The proportion of reports that were serious increased from 34% in 1992 to 49% in 1994. The overall quality of the reports made in 1994 was higher than that of the 1993 reports. In particular, significantly higher percentages of reports in 1994 indicated whether the drug was a new molecular entity, indicated whether the event was serious, and gave laboratory and clinical information in support of the event diagnosis. Reports from pharmacists increased both in number and in quality. Physicians' reports were of high quality in both years, but the number of reports they made decreased. The proportion of adverse-event reports classified as serious increased between 1992 and 1994, and the quality of event reporting to FDA improved since the introduction of MedWatch.