Experience in adverse events detection in an emergency department: nature of events

The study was performed to determine the nature of adverse events in an ED.

The methodology has been described in the accompanying paper. Two by two tables were analysed using the two-tailed Fisher's exact test. A P-value of < or =0.05 was considered significant. Statistical analysis was performed using MINITAB.

One hundred and ninety-four events were detected, from a sample of 3222 patients. Except where specified, events with management causation < or =3 were excluded. This excluded 24 events (12.4%) leaving 170 for analysis. Errors of commission occurred in 55% and omission in 45%. Errors of commission were significantly associated with prior events, errors of omission with ED events (P < or = 0.0001, respectively). The most common cause of events was drug reactions. 1.35% had a Naranjo score > or = 1, 0.54% > or = 4. Prior events were significantly associated with adverse drug reactions (P < or = 0.0001). Drug reactions were associated with a lower preventability score (P < or = 0.0001). Diagnostic issues were present in 1.2%. All three categories, that is diagnosis not considered, diagnosis within the differential and seriousness not appreciated were associated preventability > or =4 (P < or = 0.0001, P < or = 0.02 and P < or = 0.004, respectively). Diagnostic problems were significantly associated with ED events (P < or = 0.0001).

In conclusion, the data demonstrate that events fall into two sets: prior events which are associated with errors of commission, drug reactions and lower preventability; and ED events which are associated with errors of omission, diagnostic issues and high preventability.