Adverse drug events and medication errors in Australia

PURPOSE: To review information about adverse drug events (ADEs) and medication errors in Australia. DATA SOURCES: Systematic literature reviews and reports from data collections of the Australian Bureau of Statistics, Institute of Health and Welfare, Council for Health Care Standards and Patient Safety Foundation. RESULTS: (medical record reviews): We have shown that 2-4% of all hospital admissions, and up to 30% for patients > 75 years of age, are medication-related; up to three-quarters are potentially preventable. RESULTS (routine data collections): Routine death certificate and hospital discharge data coded using the International Classification of Diseases capture less than half as many ADEs as medical record reviews. Of coded adverse events that contributed to death, 27% involved an ADE, as did 20% of adverse events identified at discharge and 43% at general practice encounters. There is a strong correlation between increases in medication use and rates of adverse drug reactions (ADRs) associated with hospitalization. RESULTS (drugs implicated): These were similar in all the above studies: anticoagulants, anti-inflammatory drugs, opioids, anti-neoplastics, antihypertensives, antibiotics, cardiac glycosides, diuretics, hypoglycaemic agents, steroids, hypnotics, anticonvulsants, and antipsychotics. RESULTS (clinical indicators): An ADE is reported in 1% of hospital admissions, while some hospitals do not report ADRs to the national collection. Only three-quarters of patients with acute myocardial infarction receive thrombolytics within 1 hour of presentation. Five per cent of patients on warfarin record an international normalized ratio > 5, and 1%, 0.05%, and 0.2% -suffer abnormal bleeding, cerebral haemorrhage, or death, respectively. RESULTS (the Australian Incident Monitoring System): Twenty-six per cent of 27 000 hospital-related incidents were medication-related, as were 36% of 2000 anaesthesia-related incidents, and 50% of 2500 general practice incidents. RESULTS (errors): Errors occur in 15-20% of drug administrations when ward stock systems are used and 5-8% when individual patient systems are used. Previous allergic reactions to drugs may not be recorded more than 75% of the time. CONCLUSION: ADEs are common in the Australian health system. Anticoagulant, anti-inflammatory, and cardiovascular drugs feature prominently as preventable, high impact problems, and collectively make up over one-half of all ADEs. Methods for monitoring and preventing ADEs should be progressively improved.