"Our study revealed that experiencing an ADR [Adverse Drug Reaction] while hospitalized substantially increased the risk of death (1971 excess deaths, OR 1.208, 95% CI 1.184-1.234). This finding reflects about a 20% increase in mortality associated with an ADR in hospitalized patients. Extrapolating this finding to all patients suggests that 2976 Medicare patients/year and 8336 total patients/year die in U.S. hospitals as a direct result of ADRs; this translates to approximately 1.5 patients/hospital/year."

Source

C. A. Bond, PharmD, FASHP, FCCP and Cynthia L. Raehl, PharmD, FASHP, FCCP, "Adverse Drug Reactions in United States Hospitals," Pharmacotherapy, 2006;26(5):601-608.