Similar to previous studies, almost a quarter (22.7%) of active-care patient deaths were rated as at least possibly preventable by optimal care, with 6.0% rated as probably or definitely preventable. Interrater reliability for these ratings was also similar to previous studies (0.34 for 2 reviewers). The reviewers’ estimates of the percentage of patients who would have left the hospital alive had optimal care been provided was 6.0% (95% confidence interval [CI], 3.4%-8.6%). However, after considering 3-month prognosis and adjusting for the variability and skewness of reviewers’ ratings, clinicians estimated that only 0.5% (95% CI, 0.3%-0.7%) of patients who died would have lived 3 months or more in good cognitive health if care had been optimal, representing roughly 1 patient per 10 000 admissions to the study hospitals.
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Medical errors are a major concern regardless of patients’ life expectancies, but our study suggests that previous interpretations of medical error statistics are probably misleading.
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In an exchange about the validity of these estimates, McDonald et al argued on theoretical grounds that these statistics are likely overestimates. They were particularly concerned about the lack of consideration of the expected risk of death in the absence of the medical error. Indeed, these statistics have often been quoted without regard to cautions by the authors of the original reports, who note that physician reviewers do not believe necessarily that 100% of these deaths would be prevented if care were optimal.
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As predicted on theoretical grounds, many deaths reportedly due to medical errors occur at the end of life or in critically ill patients in whom death was the most likely outcome, either during that hospitalization or in the coming months, regardless of the care received. However, this was not the only—or even the largest—source of potential overestimation. Previously, most have framed ratings of preventable deaths as a phenomenon in which a small but palpable number of deaths have clear errors that are being reliably rated as causing death. Our results suggest that this view is incorrect—that if many reviewers evaluate charts for preventable deaths, in most cases some reviewers will strongly believe that death could have been avoided by different care; however, most of the “errors” identified in implicit chart review appear to represent outlier opinions in cases in which the median reviewer believed either that an error did not occur or that it had little or no effect on the outcome.
On the 98,000 figure this may bring some balance:
ETA: see also, primary source for the 98,000 figure (try and find it!), this discusses the 98,000 figure as a Fermi estimate