Estimation of the number of patient deaths recognized by a medical practitioner as caused by adverse events in hospitals in Japan: A cross-sectional study.

Chart reviews have been used to assess the incidence and impact of adverse events, but most of them are not a nationally representative sample. In addition, the definition of adverse events is generally broad and covers unintended events; the relationship to outcome is often unclear, and official estimates have not matched those of medical practitioner's recognition. The number of patient deaths from adverse events remains unknown.