Economic analysis of the prevalence and clinical and economic burden of medication error in England

To provide national estimates of the number and clinical and economic burden of medication errors in the National Health Service (NHS) in England.

We used UK-based prevalence of medication errors (in prescribing, dispensing, administration and monitoring) in primary care, secondary care and care home settings, and associated healthcare resource use, to estimate annual number and burden of errors to the NHS. Burden (healthcare resource use and deaths) was estimated from harm associated with avoidable adverse drug events (ADEs).

We estimated that 237 million medication errors occur at some point in the medication process in England annually, 38.4% occurring in primary care; 72% have little/no potential for harm and 66 million are potentially clinically significant. Prescribing in primary care accounts for 34% of all potentially clinically significant errors. Definitely avoidable ADEs are estimated to cost the NHS £98 462 582 per year, consuming 181 626 bed-days, and causing/contributing to 1708 deaths. This comprises primary care ADEs leading to hospital admission (£83.7 million; causing 627 deaths), and secondary care ADEs leading to longer hospital stay (£14.8 million; causing or contributing to 1081 deaths).

Ubiquitous medicines use in health care leads unsurprisingly to high numbers of medication errors, although most are not clinically important. There is significant uncertainty around estimates due to the assumption that avoidable ADEs correspond to medication errors, data quality, and lack of data around longer-term impacts of errors. Data linkage between errors and patient outcomes is essential to progress understanding in this area.