Posts Tagged ‘Why health statistics are frightening’

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3. Stuff Ups 1

June 14, 2013

You go to the doctor with lower back pain.

bad back

The doc recommends an MRI scan. A problem is identified and an operation, perhaps, recommended. But here is the problem. The back problem identified in the scan may not be the cause of the pain.

Risks: health screening

In maths this is called FALSE ATTRIBUTION.

You get all the pain – financial and physical – but no gain.

You will find a very interesting discussion of this problem The Health Report, Radio National, ABC.

Dentists suffer a higher incidence of lower back pain … Maybe from prancing around in towels in front of mirrors. Wait. That was only a small sample of 10 paid dentists.

No conclusion can be drawn.

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4. Stuff Ups 2

June 14, 2013

All medical tests are subject to a % error.

oops

This is a FALSE POSITIVE.

This may not be a problem if you are advised to, say, take more Vitamin D to correct the problem you don’t have. But if you are being advised to undergo major surgery, a second test is advisable.

As statistician Michael Blastland explained in Everyday risks: when statistics can’t predict the future (The Guardian 9 JUN 2013):

False positives are common for the simple reason that if you test a million healthy people, even with a 99% accurate test, you will still have 10,000 wrong results. And that’s not including human error. Hopefully, you will not experience one of these:

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