anticoagulants, and diuretics are at greatest risk for experiencing a preventable ADE. Nursing home residents may also be especially vulnerable to medication errors as they move between different settings of care, such as from the ambulatory setting to the nursing home, and back and forth to the hospital during episodes of acute illness.
In the ambulatory setting, the best-understood aspects of medication error rates are prescribing errors in ambulatory primary care clinics and dispensing errors in community pharmacies. There is some understanding of the incidence of ADEs in ambulatory care and self-care errors. There is limited understanding of incidence rates in care transition situations, medication administration and monitoring in ambulatory care, mail order pharmacy, and school care (Forster et al., 2003). Little information exists as well concerning medication errors associated with prescribing in ambulatory specialty clinics. Specialty clinicians typically prescribe a limited set of medications (for example, chemotherapeutic agents). Nonetheless, specialists often work with incomplete medication data on patients that are referred or transitioning between settings—situations known to increase the risk of errors (Fernald et al., 2004).
New studies should focus especially on error incidence rates associated with care transitions, medication administration in ambulatory care, monitoring of medications in ambulatory care, mail order pharmacy, and school care. In addition, not enough is known about what happens between the time a prescription is filled and the time the patient is supposed to take a particular dose of the medication at a particular time. Such research is difficult for multiple reasons, although technological approaches using smart pill bottles and bioassays can be used. However, the very act of intrusive observation raises questions about the generalizability of results obtained with these approaches.
Despite extensive work on medication errors in the hospital setting, the committee found only a handful of studies on medication errors in pediatric patients in the emergency department, ambulatory care, and home environments, all of which are critical targets for future research. The home environment in particular should be a high priority given the growing reliance on home care for increasingly complex medical conditions. All three of the existing studies involving home medication administration (Li et al., 2000; McErlean et al., 2001; Goldman and Scolnik, 2004) focused narrowly on the administration of antipyretics. These studies estimated significant rates