800 avoidable asthma deaths: do media reports reflect the research?

A report looking at annual deaths caused by asthma was widely covered in the media today.

Some papers, such as the Sun and the Daily Mail, have said its findings mean that there are 800 'needless' deaths from asthma every year.

But it isn't clear whether the report can be interpreted in this way. We've asked its author for more detail on some key questions:

Is a death caused by "potentially avoidable factors" the same as a "needless" death?

The report looked at 195 people who had died of asthma. Of these deaths 130, or 67%, had at least one "potentially avoidable factor". These included aspects of their care, such as the expertise of diagnosing doctors, and of their own behaviour, such as whether they smoked.

Between 1,000 and 1,200 people are estimated to die of asthma each year. If 67% of 1,200 deaths had "potentially avoidable factors" too, and if all of them would otherwise have lived, 800 deaths could have been avoided.

But a number of factors might have contributed to many of the deaths, and the report isn't clear that eliminating the potentially avoidable causes would have prevented every one of them.

How representative was the group looked at?

The 195 people looked at by the study aren't necessarily that similar to the 1,200 people thought to die of asthma a year.

The researchers filtered out some cases, such as where the person was 75 or over, and were unable to collect sufficient information on the medical histories of 270 people. And of the cases where there was enough information to be reviewed, an expert panel concluded that over a fifth had not died of asthma at all.

We don't know the 1,200 estimate was arrived at and hence how similar these people are likely to be to the 195 looked at by the study. So the newspapers' estimate of 800 deaths may not be accurate.

We'll be publishing a full factcheck, where we hope we can answer some of these questions, once we've heard back from the report's author.