PREVALENCE AND ECONOMIC BURDEN OF MEDICATION ERRORS IN THE NHS IN ENGLAND: Rapid evidence synthesis and economic analysis of the prevalence and burden of medication error in the UK

SUMMARY

1. A medication error is a preventable event that may lead to inappropriate medication use or patient harm.

2. We found 36 studies reported error rates in primary care, care homes and secondary care, and at the various stages of the medication pathway, ranging from 0.2% to 90.6%. Errors were more likely in older people, or in the presence of co-morbidity and polypharmacy.

3. We found four UK studies on the cost of medication errors in specific settings, with a wide range of estimates for costs from €67.93 per intercepted error for inhaler medication to €6,927,078.96 for litigation claims associated with anaesthetic error.

4. We estimated that 237 million medication errors occur at some point in the medication process in England per year. This is a large number, but 72% have little/no potential for harm. It is likely that many errors are picked up before they reach the patient, but we do not know how many.

5. We estimated that 66 million potentially clinically significant errors occur per year, 71.0% of these in primary care. This is where most medicines in the NHS are prescribed and dispensed. Prescribing in primary care accounts for 33.9% of all potentially clinically significant errors.

6. Error rates in the UK are similar to those in other comparable health settings such as the US and other countries in the EU.

7. There is little evidence about how medication errors lead to patient harm. We had to estimate burden using studies that measured harm from adverse drug reactions (ADRs). The estimated NHS costs of definitely avoidable ADRs are £98.5 million per year, consuming 181,626 beddays, causing 712 deaths, and contributing to 1,708 deaths. This can be divided into:

 Primary care ADRs leading to a hospital admission (£83.7 million; causing 627 deaths);

 Secondary care ADRs leading to a longer hospital stay (£14.8 million; causing 85 deaths and contributing to 1,081 deaths).

8. Non-steroidal anti-inflammatory drugs, anticoagulants and antiplatelets cause over a third of admissions due to avoidable ADRs. Gastrointestinal (GI) bleeds are implicated in half of the deaths from primary care ADRs. Older people are more likely to suffer avoidable ADRs.

9. These estimates are based on studies at least 10 years old so may not reflect current patient populations or practice. This may be an underestimate of burden as only short-term costs and patient outcomes are included, and we had no data about the burden of errors in care homes.

10. Future work should focus on improving routine collection of information about errors and patient harm, and supporting implementation of evidence-based interventions to reduce errors.