We can next ask ourselves, what are the health care costs associated with adverse drug reactions?  Again, methodological constraints limit making completely accurate estimates, but one estimate of the cost of drug-related morbidity and mortality is $136 billion annually,{Johnson} which is more than the total cost of cardiovascular or diabetic care in the United States.  In addition, one out of 5 injuries or deaths per year to hospitalized patients may be as a result of ADRs.{Leape}  Finally, a two-fold greater mean length of stay, cost and mortality has been reported for hospitalized patients experiencing an ADR compared to a control group of patients without an adverse drug reaction.{Classen}

Johnson JA, Bootman JL. Drug-related morbidity and mortality. A cost-of-illness model. Arch Intern Med 1995; 155(18):1949-1956.

Leape LL, Brennan TA, Laird N, Lawthers AG, Localio AR, Barnes BA et al. The nature of adverse events in hospitalized patients. Results of the Harvard Medical Practice Study II. N Engl J Med 1991; 324(6):377-384.

Classen DC, Pestotnik SL, Evans RS, Lloyd JF, Burke JP. Adverse drug events in hospitalized patients. Excess length of stay, extra costs, and attributable mortality. JAMA 1997; 277(4):301-306.