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Here’s an NNT for your thoughts



So there I was, innocently reading NICE’s multimorbidity guidance. True, that’s not a combination of words you’d necessarily expect at the top end of a Copperfield blog. But I look at these things so you don’t have to. In fact, this latest effort is relatively OK, although, where NICE guidance is concerned, that ‘relatively’ is very heavily weighted.

And that’s why I fell off my chair

Anyway, in the midst of all that frailty, polypharmacy and care-planny stuff, there was this link to a ‘database of treatment effects’, which I checked out, on account of not getting out much these days. And that was the point when I fell off my chair.

To explain, I’ve got into bad prescribing habits. In particular, I have neglected the concept of ‘number needed to treat’ (NNT). It’s probably lurking on my computer system somewhere, along with other, smiley-faced patient decision aids that I don’t use. Why would I, given I’ve been so crushed by the QOF/workload/boredom that my shared decision making when, say, prescribing statins for CVD prevention, amounts to ‘take these or die’.

And now this. To take a random example from the guidance, anticoagulation for stroke prevention in atrial fibrillation – currently seen as the go-to, evidence-based, incentive-encouraged, numero uno, no-ischaemic-brainer intervention – has an NNT over one year of 40. Which is, you know, not bad, but still leaves 39 punters popping expensive/inconvenient anticloggers for nothing every year. Or far worse than nothing, if you happen to bleed to death.

Statins in secondary CV prevention, then? I’m a sceptic, but even at my most rampantly scepticaemic, I happily dish out the nation’s favourite prescribed drug to the cardiologically compromised. NNT over one year to prevent one CV death? 239. Yowzers.

But, of course, statins in primary prevention is the Big One, and you’ll be familiar with those rewarding visits from patients sent by pharmacists or mobile units; since I refuse to do those stupid Health Checks myself, they’re performed by feckless buffoons, who terrify patients with complex concepts such as ‘heart age’.

And guess what? For primary prevention with statins, we suffer these interactions and patients suffer this anxiety all for an NNT of – wait for it – 595.

And that’s why I fell off my chair. I repeat, we treat 595 patients for one year to prevent one death. Yes, 594 patients needlessly medicalised, pointlessly popping pills, having cholesterols, using up appointments and causing me unnecessary arseache. No wonder the NHS is burnt out, broke and batshit bonkers. This is, by any sane judgement, insane.

So thanks, NICE. I see what you mean in your multimorbidity guidance when you tell us to think about what we’re trying to achieve, and to rationalise treatment when we can. But how about we do that by preventing doctor-initiated multimorbidity in the first place? After all, it’s all about prevention, isn’t it?

Number needed to stop? All of us.

Dr Tony Copperfield is a GP in Essex. You can follow him on Twitter @DocCopperfield