A systematic review of 55 quantitative and qualitative studies of the causes of medication administration errors (MAE)s was recently published with unsurprising results. The majority of studies investigated errors directly involving nurses, although anesthesiologists were also studied.   Results were grouped into either unsafe human behavior, or local workplace factors. The most common cause of administration error was human error, which was influenced by lack of concentration, complacency, or distraction. Less common were knowledge-based errors. The work environment contributed as well; with malfunctioning equipment, difficult technology, poor staffing and high workloads. The authors conclude that MAEs have multiple etiologies; however, the method by which these arise and how they interconnect is not well understood.