Why are fair tests of treatments needed?

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  • Format Audio, Texts, Websites
  • Language/s English
  • Target Audience Self-directed learning
  • EBM Stage 0 - Why EBM?
  • Duration <5 mins
  • Difficulty Introductory

Key Concepts addressed


In this sub-section

Nature, the healer

Many health problems will tend to get worse without treatment, and some will get worse in spite of treatment. However, some get better by themselves – that is, they are ‘self-limiting’. As one researcher involved in testing a proposed treatment for the common cold put it: ‘if a cold is treated energetically it will get well in seven days, while if left to itself it will get well in a week’.[1] Put more cynically, ‘Nature cures, but the doctor takes the fee.’

[thumb]And of course, treatment may actually make matters worse. It is because people often recover from illness without any specific treatment that the ‘natural’ progress and outcome of illnesses without treatment must be taken into account when treatments are being tested.

Think about a time when you have had a sore throat, a stomach cramp, or an unusual skin rash. These will often resolve on their own, without formal treatment. Yet, if you had received treatment (even an ineffective treatment), you might have assumed that the treatment caused the symptoms to disappear. In short, knowledge of the natural history of an illness, including the likelihood that it will get better on its own (spontaneous remission), can prevent use of un-needed treatments and false beliefs in unproven remedies.

When symptoms of an illness come and go, it is especially difficult to try to pin down the effects of treatments. Patients with arthritis, for example, are most likely to seek help when they are having a particularly bad flare-up – which, by its very nature, is unlikely to be sustained. Whether the treatment they then receive is mainstream or complementary, effective or ineffective, it is likely that their pain will improve after receiving it, simply because the flare-up dies down. Understandably, however, practitioners and patients will tend to attribute such improvements to the treatment taken, even though it may have had nothing to do with the improvements.

NextThe beneficial effects of optimism and wishful thinking


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Ichalmers 01:45am Mon 20 Feb 2012

? link from •Nature, the healer (this page) to beginning of main text

13:50pm Thu 23 Feb 2012


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