Tuesday 19 December 2023

Dodgy obesity stats


The Times has become obsessed to the point of derangement about obesity and food. Its front page yesterday claimed that obesity-related hospital admissions have doubled in just six years. This statistic doesn't pass the smell test, as I explain on my Substack.
 

When statistics like this rise or fall dramatically in a short space of time, it is usually worth looking for a change in methodology. Sure enough, what we have here is a sharp rise in the number of people going to hospital with a secondary diagnosis of obesity. Back in 2009/10, only 142,219 admissions had obesity mentioned as a secondary diagnosis. By 2022/23, this had risen to 1,235,961. In the same period, the rate of obesity among adults has risen only slightly. A ten-fold rise in admissions isn’t very plausible, especially since admissions for which there was a primary diagnosis of obesity haven’t risen at all.

A secondary diagnosis of obesity doesn’t mean that your illness was caused by obesity, nor does it mean that you wouldn’t have got ill if you hadn’t been obese, as the statisticians who collate this data explain

A secondary diagnosis of obesity does not necessarily indicate obesity as a contributing factor for the admission, but may instead indicate that obesity is a factor relevant to a patient’s episode of care.

For example, if an obese woman goes to hospital to have a baby, that is not an obesity-related admission in the sense that it could have been avoided if she wasn’t obese, but it will be recorded as such if a medic thinks her obesity is relevant to her care. This is not a random example. Maternal care is, by some distance, the most common type of admission to have a secondary diagnosis of obesity recorded.

 


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