Overall Summary of the Three Series

OVERALL SUMMARY OF THE THREE SERIES

Table 50.1 presents a general summary of the three series. Overall, the number of deaths per year has decreased, whereas the number of Coroner’s inquests being undertaken has increased. The number of drug-related deaths per year also appears to have increased in the third series, but it is difficult to make compar-isons between the three series due to different methods in identifying drug-related deaths.

The drugs associated with fatal adverse drug events over the course of the three series are presented in Table 50.2. The most startling difference between the three series of reports is that NSAIDs no longer account for the majority of the deaths and that there is a significant increase in the number of deaths that is associated with warfarin. Table 50.3 demonstrates the increase in warfarin-associated deaths identified in the Coroner’s inquests since 1986. Over the course of a 10-year period (1986–95), only two cases were found to be associated with warfarin compared with 17 cases from 1996 to June 2005. A similar trend over the same period is evident in the number of fatal suspected ADRs to warfarin spontaneously reported to the United Kingdom Medicines and Healthcare prod-ucts Regulatory Agency (MHRA) and the Committee on Human Medicines (CHM) through the Yellow Card scheme.

This increase in the number of fatal suspected ADRs due to warfarin may be explained by the increased use of warfarin in drug therapy. Data obtained from the Department of Health indicate an increasing trend in the number of warfarin prescriptions in the commu-nity in England from 1991 to 2004 (Figure 50.1). When the data from the Yellow Card scheme are plot-ted alongside the number of warfarin prescriptions, a strong positive correlation is observed between the increasing number of reports of deaths suspected to be associated with warfarin and increasing medica-tion use (Spearman = 0.839, P < 0 0005). This association is, however, constrained by the inherent limitations of a spontaneous reporting scheme, as the incidence of deaths due to warfarin treatment cannot be determined through the Yellow Card scheme.