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Independents' Day

NNTs for common conditions

An at-a-glance guide to the number needed to treat for various interventions - click to view full chart

Click on the image below to download the full table



NNT table download

NNT table download

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Readers' comments (5)

  • Spuds

    Thanks Pulse - very useful

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  • Knowledge is Porridge

    right, time to start taking an antidepressant and stop prescribing the rest. Tomorrow should be a quiet days work.

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  • AlanAlmond

    Really informative wonder antidepressants are so widely prescribed ..they work

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  • Dear jobbingdoc. please don't interpret this chart as meaning antidepressants work. Google Irving Kirsch's met-analysis. No better than placebo. No evidence for the roll of serotonin in depression in the first place - it's just an hypothesis. We have been brainwashed along with the public for decades to believe that these drugs work (better than placebo that is) My local psychiatrist told me the don't work. They are a waste of money and resources and it's a scandal that patients see their issues as serotonin deficiency which means they become to rely on them every time life gets tough. How many consultations are wasted tinkering with patient's serotonin levels? There isn't even any evidence that they actually alter the levels in the first place. As for any trial evidence - go to and you'll see how poor the evidence is that us poor souls have to make decisions. As for the chart - excellent - when you explain to patients that so few patients benefit from so many of our drugs they often decline to take them.

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  • Irving Kirsch's meta-analysis doesn't disprove SSRI effect - much like the JAMA meta analysis it shows SSRI effect is minimal or negligible for mild-moderate cases, but has an effect on severe depression. In addition, for a study on class effect, they've notably excluded sertraline and citalopram (apart from fluoxetine, two of the most used), particularly as systematic Cochrane review has shown sertraline to be superior to other antidepressants.

    I think you're right about there being an over-emphasis on medicalising social issues and pathologising natural variations in mood, but I wouldn't dismiss the medications as a whole when they have some evidence of benefit in severe cases. In addition, user perception of SSRIs amongst psychiatrists is highly variable, and there's little point in citing meta-analyses and systematic reviews in the same sentence as anecdotal evidence from a single clinician.

    Much like most truth, the answer probably lies somewhere between those people advocating prozac being put in the water supply and those people flooding the internet with all-caps tirades against SSRIs causing akithesia in all patients- it may be closer to one side than the other, but I think all that can be said currently is that the evidence is a grey area and hopefully further research and transparency will help clarify things. Even Goldacre, helming alltrials, is relatively ambivalent about antidepressants as a whole - his main battle is regarding transparency, not an assault on the actual medications themselves. Once access to all data is achieved, then a reasonable assessment can be revised.

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