Defining the contribution of human error to adverse events in a surgical service

This study aimed to assess the contribution of human error to adverse events over 10 years in a single surgical department in South Africa.

A retrospective database analysis was undertaken to identify all adverse events, which were further assessed to identify which were error-associated.

A total of 14 237 adverse events occurred between December 2012 and January 2023, of which 7 504 (52.7%) were judged to be error-associated. An error rate of 14% per admission, or 2% per inpatient day was shown. Errors during delivery of care accounted for 76% of all errors and 40% of all adverse events. Of those, medication errors contributed 29%, those due to indwelling devices contributed 28%, and iatrogenic injuries 18%. Errors in assessment accounted for 14% of the total errors and 7% of all adverse events, with clinical assessment failure contributing 55.8% and missed injuries 19%. Mixed type errors contributed 10% of the total. Assessment by year demonstrated an upward trend from 2013 to 2016, followed by a downward trend from 2016 to 2022. Error-associated adverse events increased length of stay and mortality significantly.

Error contributes to more than half of adverse events and increased length of stay and mortality and is potentially avoidable. Errors may occur at any stage during an admission and highlights the need for multilevel interventions. The decrease in error noted is due to the cumulative effect of multiple endeavours, and not a single intervention.