How many prescription errors are doctors making?

2 May 2012

The Times, Morning of 2 May 2012

"Of the 900m written out each year one in about 500 — or about 1.8m — contains severe errors that could put lives in danger, the research commissioned for the General Medical Council found".

The Times, Afternoon of 2 May 2012

"Almost two million GP prescriptions contain potentially life threatening errors with mistakes in those given to one in five patients".

Telegraph, 2 May 2012


Daily Express, 2 May 2012

"One in eight of all patients had a prescription item with an error".

Daily Star, 2 May 2012

Apparently there's nothing like rumours of medical negligence to make the headlines. Today a report from the General Medical Council on how often GPs are not prescribing or monitoring their prescriptions properly made it into the above news outlets, as well as the Guardian, the Independent, the BBC, ITV and Sky.

But why do all the articles have such different figures?


The study looked at 6,048 unique prescription items and 1,777 patients; a select sample of the 900 million individual prescriptions which are dispensed throughout England annually. It looks at two factors:

It opens with the main findings, that:

"Prescribing or monitoring errors were detected for one in eight patients, involving around one in 20 of all prescription items. The vast majority of the errors were of mild to moderate severity, with one in 550 items being associated with a severe error".

These statistics confirm first the Star's figures on one in eight patients, and then the Times' figures from this afternoon of one in 500 prescriptions defined as severe errors.

This morning the Times online had the figure wrong, stating that 180,000 prescriptions contained severe errors. Full Fact were pleased to see that they replaced this with the correct figure of 1,800,000, which is what ran in the paper. To come to the 2 million figure the Telegraph will have rounded up from the 1.8m figure which the Times found.

But if the GMC found that one in eight patients experienced prescribing or monitoring errors, where did the Express and Telegraph get their above figures from?

Looking further into the report reveals that, unlike the other papers, they are not talking about all patients.

In the Telegraph article the one in five figure is originally quoted in the subheading, but it is also mentioned in the body of the text:

"It was found that one in five patients who were taking medicines had been given a prescription with an error in it".

So the one in five figure refers specifically to patients who were already taking medicines. This can be found in the report:

The GMC's findings here are all the more credible because they used confidence intervals to account for the sample size being smaller than the actual 900 million prescriptions and related patients in the country. Their midpoint — 17.8 per cent — also sits neatly between twenty per cent and 16.6 per cent, which means it could either equate to the Telegraph's one in five patients or the Express' one in six.


Looking further into the GMC report's figures reveals why the papers used so many different numbers.

The report looked in to a variety of things: from the severity of the mistakes, to types of patients affected and the number of prescriptions affected. This meant that there was a wealth of information in the media, which was then interpreted in different ways and often rounded up and down. All the articles seem to have made a fair representation of different findings from the report.

Image credit: e-Magine Art

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