Adverse drug events in U.S. adult ambulatory medical care.

TLDR: A greater focus on ADE prevention and detection is warranted among patients receiving multiple medications in primary care practices, and the majority of these in outpatient office practices.

Abstract: Ensuring patient safety is a major public health challenge. According to the Institute of Medicine (IOM), in the United States, as many as 98,000 deaths per year are attributable to preventable adverse events that occur in the hospital setting, with annual costs (lost income, disability, and health care costs) of between U.S.$17 billion and U.S.$29 billion(IOM 2000). Because the patient safety movement originated in and has focused on acute care settings (IOM 2000), less is known about safety outside the hospital setting (Wachter 2006; Sarkar et al. 2009). Adverse drug events (ADEs), defined as injuries resulting from a medication taken for medical intervention (Bates et al. 1995; Gurwitz et al. 2003; Bourgeois et al. 2009), constitute an important aspect of patient safety. Not all ADEs are preventable or can be considered medical errors; nevertheless, detection and prevention of ADEs is central to improving safety. Several studies have reported high rates of ADEs among specific populations, such as elderly patients (Gurwitz et al. 2003) and those with chronic diseases (Zhang et al. 2007), but important gaps in our current understanding of ambulatory ADEs remain. Apart from studies focused exclusively on emergency departments (EDs) (Budnitz et al. 2006, 2007), national population estimates for ADEs in the United States are lacking. Accordingly, we analyzed data from the National Center for Health Statistics (NCHS) to describe the frequency and distribution of ambulatory ADEs among U.S. adults, to estimate age-specific rates for ADE visits. In addition, we explored which medication classes are most commonly reported in ADE visits, and whether demographic and clinical characteristics were associated with ADE visits.