Detection of adverse events in a Scottish hospital using a consensus-based methodology.

OBJECTIVE: To determine, using a consensus based methodology, the rate and nature of adverse events (AEs) among patients admitted to acute medicine, acute surgery and obstetrics in a large teaching hospital in Scotland.
METHODS: Retrospective case-note review of 450 medical, nursing and medication records to identify and classify adverse events. For 354 patients whose length of stay was greater than 24 hours, the overall adverse event rate was 7.9% which ranged from 0% in obstetrics, 7.2% in acute medicine to 13% in acute surgery. Among all AEs, 43% were deemed preventable by a consensus group and 59% of the AEs contributed to a proportion of the patients' hospital stay or led to hospital readmission. Whilst nurse identification of adverse events was highly specific (94%), its sensitivity was poor (43%). Only 10% of the identified AEs were identified by the hospital's voluntary reporting system for adverse events. The estimated additional cost of adverse events in terms of bed days was ł69,189 which if extrapolated Scotland-wide could cost ł297 million per annum.
CONCLUSIONS: This study supports the need to continue the traditional retrospective record review to identify adverse events. The current hospital-based reporting of adverse events does not provide a complete measure of adverse events and needs to be complemented by other measures.