NPC Archive Item: Further confirmation on the scale of drug-related incidents in hospitals

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Updated: 29th July 2008

The incidence and nature of in-hospital adverse events: a systematic review.

What is the background to this?
Although there are many studies that have looked at the causes of adverse events in hospitals, including those that involve medication, there are few reviews that summarise these papers. The authors of this report conducted a systematic review (Embase, Cochrane and Medline) of published literature on in-hospital adverse events. This included an analysis of adverse events that identified those that were drug-related and an estimate of the number that were potentially preventable.

Eight studies (74,485 patients) from the published literature internationally met the selection criteria:

  • An adverse event was defined as an unintended injury or complication resulting in prolonged hospital stay, disability at the time of discharge or death, and caused by healthcare management rather than the patients underlying disease process.
  • The median overall incidence of adverse events was 9.2% with a median percentage preventability of 43.5%.
  • Of these the median percentage attributed to medicines was 15.1% (interquartile range 11.9 to 20.4).
  • Evidence-based interventions intended to reduce medicine-related events included computerised physician order entry (electronic prescribing), clinical pharmacy services, use of bar code technology in pharmacy, and patient self-management of anticoagulation.

How does this relate to other publications or evidence?

In 2007, the National Patient Safety Agency published a report1 from its patient safety observatory on medication incidents in the NHS. This reported that between 3.5% and 9% of hospital in-patients experience harm from medicines. The findings from this systematic review seem to be of a similar order of magnitude to the data from the NPSA report, although direct comparisons are not possible due to differences in terminology and definitions of adverse drug events included in the study

The Impact
Adverse events related to medicines are a serious health issue. Medical errors cause levels of mortality higher than more high-profile health problems such as breast cancer or AIDS.2 In addition to the harm caused to individual patients, they also place a significant burden on healthcare resources. Our own experiences working with hospitals involved in the NPC HMMC improvement programme identified that adverse drug events are under-reported. Particularly where these were related to system failures rather than the pharmacological or toxicological properties of the drug.

Given that a significant proportion of medicines-related incidents could potentially be avoided, there is an opportunity to improve health and avoid unnecessary expenditure by relatively simple interventions. Commissioners might wish to consider including such interventions in commissioning agreements with local trusts.

Item details
De Vries EN, Ramrattan MA, Smorenburg SM et al. The incidence and nature of in-hospital adverse events: a systematic review. Qual Saf Health Care (2008): 17(3); 216-223

1. National Patient Safety Agency. The fourth report from the Patient Safety Observatory
Safety in doses: medication safety incidents in the NHS. NPSA (2007): London
2. Kohn LT. To err is human: building a safer healthcare system. Institute of Medicine (1999)

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