Exploring the causes of adverse events in NHS hospital practice

In a previous paper we reported that 10.8% of patients admitted to two larg e hospitals in Greater London experienced one or more adverse events, of wh ich half were deemed preventable. Here we examine the underlying causes of errors in clinical practice. Rather than identifying specific errors made b y individuals, we have looked at possible faults in the organization of car e. Adverse events were grouped according to stages in the care process: dia gnosis, preoperative assessment and care, operative or invasive procedure ( including anaesthesia), ward management, use of drugs and intravenous fluid s and discharge from hospital. Less than 20% of preventable adverse events were directly related to surgic al operations or invasive procedures and less than 10% to misdiagnoses. 53% of preventable adverse events occurred in general ward care (including ini tial assessment and the use of drugs and intravenous fluids) and 18% in car e at the time of discharge. Probable contributory factors in these errors i ncluded dependence on diagnoses made by inexperienced clinicians, poor reco rds, poor communication between professional carers, inadequate input by co nsultants into day-to-day care, and lack of detailed assessment of patients before discharge.