Neil Hopcroft

[Listened as audiobook]

https://www.penguinrandomhouse.com/books/205067/overdiagnosed-by-h-gilbert-welch

This is a book about overdiagnosis of medical conditions, it digs in to the problems of screening and some implications of discovery of “incidental-oma”s, growths seen on a scan but unrelated to the reason for the scan, and other incidental findings.

This book has put into perspective some of the things that were worrying me about screening – I knew screening was often detrimental, but I hadn’t understood quite how bad it is. There are some situations where screening is worthwhile, and likewise where medical control of proxies is worthwhile, breast cancer screening and high blood pressure being good examples. Many other screening exercises lead to anxiety and risk from intervention without improving overall outcomes.

There was also some discussion of the extension and redefinition of disease to include more people in the condition – if a condition is measured, adjusting the cutoff point for diagnosis so mild versions of the disease are included. When we do this, more people undergo more invasive diagnosis and treatment, even when the condition is not interfering in their lives.

There are also some psychological and cultural aspects to the perpetuation of screening, where people believe that they have been saved by a doctor who found something they were totally unaware of and treated it. These people then become advocates for screening, “catch it early”, “it will save your life”.

The thing to look out for is the number needed to treat, if you need to treat three or four people to save one, as is the case with high blood pressure, it is clearly worthy. If you need to treat a thousand to save one, the value is much less clear cut – indeed, if those thousand then go through a procedure or take a medicine which carries risk, as most do, you don’t need to have many side-effects or bad outcomes to cancel out that one saved per thousand.

Another concern considered in the book is about the use and abuse of statistics, looking at things like ten year survival rates from initial diagnosis doesn’t hold any value in those cases where diagnosis is accelerated by screening.

This book is grounded in the American system, where there are more financial incentives to overdiagnose otherwise well people to turn them into patients, especially where the only way to know if you are getting better is to have another scan and have the radiologist tell you it looks better – there is no symptom to be relieved.

I’m not sure how well it translates to the British health system – I would like to think that the NHS is better able to understand, and therefore deal with, the problems of overdiagnosis. The NICE guidelines should incorporate mitigations for the worst overdiagnoses, but I am also sure that there will be significant pressure from the public, and some well meaning but not so well (statistically) educated medical professionals, to perform more screening, more finding things early.

Postscript: While I was writing this review the BBC published an article about How AI can spot diseases that doctors aren’t looking for. This article is an example of the perpetuation of the myths of early diagnosis – the protagonist in the piece was ‘identified’ as having osteoporosis based on machine readings of his bone density, which is claimed human doctors are biased against looking for in middle age men – it is considered more prevalent in old thin white women. The machine was looking at a scan taken for GI related issues. This is a classic example described in the book, with a symptom free vertebra collapse and low measured bone density without any symptoms like frequent fractures. Oddly, it is only at the end of the article that there is a nod toward the harms of this kind of incidental screening, and even then it concentrates more on the harm to the NHS than the people diagnosed.

The only bit of sense in the whole article is from Prof Javaid: “We want to build the evidence to use it across the NHS”. Building this evidence in a reliable way is non-trivial, and probably involves longitudinal studies of thousands and carefully designed RCTs. My expectation would be that there are a few things where the results indicate significant improvement in overall outcomes without undue anxiety or risk, but most screening will show that it either doesn’t improve outcomes, or worse, actually causes harm. But I don’t think we have the data yet to draw robust conclusions. And I doubt there will be much funding for these kinds of studies – pharma and medical tech won’t want to go looking for results that say you should use less of their products.

The Last London [Read aloud to Adelle]

I got this book because we were reading London Orbital, Sinclairs book about a walk around London in the acoustic footprint of the M25 and didn’t want it to finish. More about that book later. This was a tricky read, with complex sentences that didn’t come out in one breathe. His writing style is intense, with many observations on people and things he encountered on his walks.

The majority of the book revolves around his locality in Haggerstone, spiralling outwards to eventually end up recreating a force march to the battle of Hastings with a parade of misfits lead by an unattached bride. This is a political discourse on the turmoil of Brexit, both before and after, an observation of the schisms in the mentality of the country.

I knew a surprising number of the places through which the recorded walks passed, and was offered a view different from those I have seen during my own ambling, with a peak into the ancient or, more often recent history, of places.

One such place I didn’t know about was Mortimer Road, home of The Mole Man of Hackney, a mere couple of miles from my first flat in London, where an eccentric Irishman burrowed an extensive network of tunnels. Karen Russo said the Mole Man proved to be extraordinarily difficult to work with, and we are left with only a few pictures of the contents of his tunnelling.

London Orbital was where it started, this was a book I read not long after it came out at the beginning of the century. It captured a time in my life when the orbital was central, when discovery of things off the tarmac was a view into a world that was not there, that did not exist because you join, you drive, find your junction and leave. There is something in all those miles in between. And, for the most part, it is asylums or plague hospitals, places to put the unseen of Victorian society so they remain unseen. And they remain unseen, for different reasons now.

I read this book to Adelle too, and was reminded of the hopeful future that pervaded my life at the time of my own escape from the gravitational capture of the capital. It is a book of its time, a time now passed, making it a history of sorts, I am pleased to note that there is a 20 year celebration on film.

Wanderlust makes me consider other walks that could yield similar works, but my control of the language falls far short of that in these books. The A14 was an obvious candidate, at one point, now there is more appeal to the liminal nature of the north Norfolk coastal path.