Friday 3 July 2015

Making sense of alcohol-related hospital admissions

The latest figures for alcohol-related hospital admissions were published last month and, over at the Alcohol Policy blog, James Morris lamented the fact that such announcements ‘no longer appear to generate significant media attention following changes to the reporting of the data’. This, he argues, is because the Department of Health prefers to use a narrow measure of ‘alcohol-related’ rather than the previous broad measure. The broad measure helped to push the number of alcohol-related hospital admissions over the (newsworthy) threshold of one million some time ago, but it was never credible. Here’s why.

The first thing to understand about alcohol-related hospital admissions is that there is no nurse on the door to judge whether your condition is due to drink. It is simply assumed that a certain proportion of each medical condition is caused by alcohol. So, for example, 15 per cent of breast cancer cases amongst women aged 45 to 54 are assumed to be caused by alcohol consumption, 23 per cent of hypertensive diseases amongst men aged 65 to 74 are assumed to be caused by alcohol, and so on, through every disease, injury and death that could possibly be due to drinking.

If this seems somewhat arbitrary, it is, but there is some science behind it. Alcohol really is a contributor to some chronic diseases and it is right that this be acknowledged in the data, however imperfectly. The problems only really arise when you start counting secondary diagnoses as alcohol-related. That is what the old ‘broad’ measure did.

Imagine that you have hypertension and you go to hospital because you have a virus. The virus is your primary diagnosis and your hypertension is your secondary diagnosis. The hypertension has nothing to do with your virus, but it is recorded in the data anyway. Although your visit to hospital was not alcohol-related in any meaningful way, hypertension is considered to be an alcohol-related condition and because you have it as your secondary diagnosis, your admission is officially alcohol-related. You have contributed to the alcohol stats without touching a drop.

Not only is this absurd, it also guarantees that the numbers will keep rising over time because the population is growing, people are getting older and, above all, clinicians are more likely to record a secondary diagnosis than they were in the past. If you ever wondered how alcohol-related hospital admissions could double in the space of a decade despite alcohol consumption falling, this is a large part of the reason.

Since many alcohol-related conditions are diseases of old age, it is a mathematical certainty that they will continue to generate more and more hospital admissions as the population expands and ages. A year-on-year increase in the number of admissions for alcohol-related pneumonia, for example, only really tells us that there has been a general rise in admissions for pneumonia. We have no idea what role alcohol played, it is just assumed that a set proportion of them were alcohol-related. We could all stop drinking tomorrow and the number of ‘alcohol-related’ admissions for heart disease and cancer would continue to rise for many years, or until the underlying assumptions were updated.

Nevertheless, even under the narrow measure, there has been a rise in admissions, from 253,000 to 333,000 since 2004, but this needs to be put in the context of a massive increase in the use of hospitals in general. In 2001, there were 12 million finished consultant episodes in English hospitals.

Last year there were 18 million. Alcohol is a factor in less than two per cent of them and most involve longterm conditions rather than acute intoxication. I mention this only because newspapers like to illustrate their stories about alcohol-related hospital admissions with photos of drunks on the pavement but, as the Office for National Statistics noted last week, only ‘950 (less than 1 per cent) of admissions were for the toxic effects of alcohol’.

In any case, the ‘public health’ lobby has no reason to worry about the Department of Health switching to a more accurate definition of an alcohol-related admission. The latest figures may not have made the front page this year, but the Mirror still reported that ‘Hospital admissions caused by alcohol have soared to one million a year’. The Express ran the news under the headline ‘Booze Britain: Drink-related hospital admissions double in a decade’. So long as the Office for National Statistics keeps publishing figures for the broad measure, we can expect them to continue being newspaper fodder for many years to come.

[Cross-posted from Spectator Health]

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