Medication safety: moving from illusion to reality.

THE IMPORTANCE OF MEDICATION SAFETY HAS BEEN RECognized for many years, but only recently has it reemerged as a major public health issue based on numerous recent studies and high-profile safety events. Drug safety dates back to the 1950s, when in response to reports of chloramphenicol-associated aplastic anemia, the American Medical Association established an adverse drug reaction (ADR) reporting system and the Food and Drug Administration began requiring pharmaceutical manufacturers to report ADRs. This effort to detect heretofore unknown, serious adverse effects of medications in postmarket use relied on voluntary reporting, which also became common practice in most health care organizations. In the 1960s, Jick and colleagues began to focus on the safety of drugs in everyday practice, using a concurrent study approach instead of voluntary reporting. The authors found that 30% of the medical inpatients in their study experienced at least 1 ADR during their hospital stay, and 3% of hospitalizations were directly attributable to ADRs. They also estimated that 29000 deaths due to ADRs occurred annually in the United States. However, adverse effects of drugs were viewed as an unavoidable part of modern medical therapy; in a later publication, Jick noted that “the rates and severity of adverse reactions to individual drugs are remarkably low in view of their pharmacological properties.” Now, 30 years later, with more sophisticated and comprehensive means to detect adverse drug events (ADEs), studies reveal that ADEs occur in 6.5% to more than 20% of hospitalized patients, and that many of these ADEs are avoidable. Tolerance for the illusion that medication safety is as good as it can be has finally begun to change. In this issue of THE JOURNAL, Gurwitz and colleagues report findings from an important new study of medication safety in the outpatient setting among Medicare patients (most of whom were enrolled in a Medicare health maintenance organization plan [Medicare+Choice Plan]). This study builds on a previous study of this group in the inpatient and nursing home settings in which they developed and tested consistent methods for the detection, characterization, and analysis of ADEs. Despite the new setting, the current study confirms many previous observations about medication safety and error, but with several important new findings. Adverse drug events occurred at a rate of 50.1 per 1000 person-years, of which 13.8 per 1000 personyears were preventable. This study indicates that the most frequent classes of drugs associated with ADEs were cardiovascular agents, antibiotics, diuretics, nonopioid analgesics, and anticoagulants. These rates largely reflect their prevalence of use with the exception of anticoagulants, which were associated with a disproportionately high rate of ADEs. As previous studies have shown, prescribing medications and appropriate monitoring of drug therapy remain significant and provide largely unmet opportunities for improvement. Of note, lack of patient adherence, known to be associated with therapeutic failure, also was found to pose a safety risk. Extrapolating the rate of ADEs from the study by Gurwitz et al to the total Medicare population, it was estimated that as many as 1900000 ADEs may occur annually and perhaps as many as 180000 of these ADEs are lifethreatening or fatal. However, as the authors acknowledge, this estimate may be conservative as several factors in their study design, including incomplete review of clinic notes and no information collected from patients, may have led to underdetection of ADEs. Obtaining an accurate measure of the scope of the problem of ADEs is a first step in addressing the problem. Most current efforts in this area use retrospective chart review to detect ADEs. The significant limitations of this approach are widely acknowledged, yet a relentless debate about this method continues. Far more attention should be focused on the critical need to develop new methods to improve the detection of ADEs and other adverse events (AEs), especially in outpatient settings where minimal tracking of these events occurs. Numerous new methods for detecting ADEs, including both electronic and chart-based approaches, are currently being developed, tested, and implemented for both inpatient and outpatient settings, and several