Use of Spontaneous Reporting System Data

To the Editor. —  Wysowski and Barash¹ present triazolam reports to the Spontaneous Reporting System (SRS) for 1983 through 1985. The authors state that their analysis of aggregate reaction reports suggests a higher occurrence of certain reactions.However, Wysowski and Barash use methods that lead them to overinterpret the SRS data. Reporting rates do not reflect incidence rates, and attempts to make comparisons among drugs are considered inappropriate and misleading.²The Food and Drug Administration (FDA) ensures that the following caveat accompanies all SRS data obtained under the Freedom of Information Act:Accumulated case reports cannot be used to calculate incidence or estimates of drug risk. They must be carefully interpreted as reporting rates and not occurrence or incidence rates. Comparisons of drug safety cannot be made from these data.This caveat results from the recognition of numerous nonquantifiable biases that are characteristic of the reporting of adverse