Study Finds High Prevalence of Adverse Drug Reactions in UK Hospitals

One out of every seven patients admitted to the hospital experiences adverse drug reactions during treatment, report researchers from the University of Liverpool, who conducted the largest prospective study to date of adverse drug reactions in UK hospital inpatients.

Patients from 12 different UK hospital wards were followed for a six-month period. Fifteen percent experienced an adverse reaction to a drug they were prescribed. Symptoms included constipation, confusion, bleeding, renal problems, and Clostridium difficle infections.

The researchers also found that an adverse drug event lengthened a patient’s hospital stay by an average of 0.25 days. Elderly patients on several different medications were the most susceptible to these reactions, which were most commonly associated with anticoagulants, analgesics, and diuretics.

“A significant predictor of ADRs in hospitals is the number of medications a patient is taking,” said Professor Munir Pirmohamed, from Liverpool’s School of Biomedical Sciences, in a release on the university’s website. “Each additional drug treatment increases the risk of experiencing an adverse drug reaction. This is one of the reasons why elderly people experience a higher incidence of ADRs than young people, as they have more health conditions and generally take more medications.”

Events suspected to be possible adverse drug reactions were recorded and analyzed for causality, severity, and whether they could have been avoided, in addition to how long a hospital stay was lengthened, according to a PLos ONE article that discussed the findings.

In addition to this initial study, another has been established to examine the methodology used in determining the burden of adverse drug reactions on inpatients.

“Our results show that the overall burden of ADRs on hospitals is high and therefore new methods of intervention are needed to reduce this,” said Pirmohamed in the university release. “The results are consistent with data from other parts of the world... We are currently looking at a number of ways of improving the safety of medicines, including increased monitoring of patients and the identification of genetic factors that could increase the risk of a patient developing adverse effects. Our ultimate aim is to use a number of inter-related methods to allow us to maximise the benefits of medicines and minimise the harm.”

Click here to read an abstract of the PLoS ONE journal article.

specialty: hospital medicine