As an admirer of the invariably high standards of CMAJ's lead editorials, I would like to record a small comment about the one on monitoring the quality of medical care delivery.1 A hospital admission is frightening enough for patients, without their learning from an authoritative source that hospitals “are particularly dangerous places” and that “the overall incidence rate of adverse events that result in death, disability or prolonged hospital stay in Canadian hospitals is 7.5 per 100 hospital admissions.” From this, the trembling patient would reasonably assume that 7.5% of admissions can be expected to result in one of these fearful outcomes. However, the source article for this statistic tells us that nearly one-third of these events occurred in the 12 months preceding the index hospital admission. Thus, the rate of adverse events occurring during a hospital stay was closer to 5.2%.2
Doctors and patients are well aware that few therapies have a 100% success rate and that perfectly appropriate treatment can be associated with unwanted outcomes. The figure we all need to know is the rate of preventable adverse events. In the study by Baker and colleagues this was 2.8%.2 We also need to know whether the consequences of these events are really “death, disability or prolonged hospital stay.” Some proportion of adverse events in the study probably resulted only in slight extensions of the patient's stay in hospital; most (56%) resulted in no impairment, minimal impairment or impairment with recovery within 1 month.2 The 7.5% figure cited in the editorial is barely relevant and unnecessarily frightening.