Costs of adverse drug reactions

Bangor University’s Professor Dyfrig Hughes, in collaboration with researchers at the University of Liverpool, has estimated the costs of hospital admissions resulting from harms caused by medicines. 

This was based on a review of the medical notes of 1187 medical admissions to the Liverpool University Hospitals NHS Foundation Trust across a one month period in 2019. 

The research is an update to a study published in the BMJ in 2004, which found that 6.5% of hospital admissions were associated with adverse drug reactions (ADRs). Our updated research found that 16.5% of admissions are caused by, or complicated by, an adverse reaction to a medicine, which represents a significant increase in that burden. 

In terms of costs, the analysis indicated that £1 in every £8 spent on the care of non-elected hospital admissions relate to the management of ADRs. Extrapolated to the NHS in England, this is equivalent to £2.2 billion annually – much higher than NICE’s previous estimate of £529 million for potentially avoidable ADR-related admissions.

The upward trend is connected to a rising tide of multiple long-term health conditions and the use of many medicines simultaneously. Patients who suffered adverse drug reactions were on average taking more medicines and had more medical conditions than those without an ADR. The problem is exacerbated in the context of overprescribing, that is, where people are given medicines they don’t need or want, or which may do them harm. Overprescribing has grown dramatically over the last 25 years. This was highlighted in a recent NHS report on overprescribing which stated that 10% of prescriptions (approximately 110 million) should not have been issued.  

This updated study confirms that the problem is increasing and that a whole-systems approach is needed to address the societal, systemic and cultural contributors to overprescribing. 

Professor Dyfrig Hughes, professor of pharmacoeconomics at Bangor University said: “Adverse drug reactions place a significant burden on patients and continue to represent a challenge to the NHS. The costs of managing patients admitted to hospitals because of medicines-related harms suggest that there is still much to be done to improve prescribing. Bangor University’s new degree course in pharmacology builds on research strengths in pharmaceutical economics, policy and prescribing research”.

Professor Sir Munir Pirmohamed of the University of Liverpool, and lead investigator said: “Our updated analysis highlights the continuing burden placed on patients and the NHS by adverse drug reactions.  There is no single simple solution to prevent this, and therefore a multi-layered approach, ranging from education on better prescribing through to the use of technologies is needed.  This would be consistent with the aims of the NHS long-term plan.”

A concerted national effort, beyond those outlined in the NHS overprescribing report, is needed to improve the benefit-risk balance of prescribed medicines, and thereby reduce the burden of ADRs on patients and healthcare services.  

The full study can be found here: 

Publication date: 3 October 2022