Objective: The study was performed to determine the nature of adverse events in an ED.
Methods: 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.
Results: 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).
Conclusion: 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.