more than medication errors with little potential for harm, although this possibility has not been assessed formally.
Very few studies have examined the costs of medication errors in individual care settings; rather, studies have focused mainly on the additional hospital costs of ADEs. One study (Bates et al., 1997) used cost data that are now more than 10 years old. There has been one study of the health care costs of treating preventable ADEs occurring in ambulatory care.
There are large gaps in our understanding of the costs of medication errors. No studies have been conducted on (1) the costs of medication errors in pediatric and psychiatric care, (2) the costs associated with errors involving OTC and complementary and alternative medications, (3) the costs of medication errors not considered ADEs, (4) the costs of the failure to receive drugs that should have been prescribed, (5) the costs of over-utilization of drugs (for example, antibiotics), and (6) the costs associated with nonadherence to prescribed drugs in the ambulatory setting. Finally, we have limited understanding of the economic and social costs of medication errors borne by patients and their families.
On the basis of the information currently available about the various types of medication errors, the committee acknowledges that it is impossible to formulate a fully comprehensive set of corrective medication error strategies. For example, there is a need to better define the impact on the incidence of errors in the medication-use stage of system problems in the research and development, regulatory review, and distribution/marketing stages (for example, inadequate information about dosages for special populations, look-alike/sound-alike drug names). In addition, the impact of underutilization of medications for the treatment of acute coronary syndromes, for antibiotic prophylaxis, and for thrombosis prophylaxis is not well understood. The area best understood is the incidence of preventable ADEs in various care settings—especially in the hospital, but also in nursing homes and in ambulatory care for adults—where significant problems and their causes have been identified. More research is needed to evaluate the impact of upstream problems on the incidence of errors in the use of medications, as well as the impact of the underutilization of medications.