Talk:Number needed to treat

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I took out this example:

the drug gabapentin, frequently used for neuropathic pain, only gives appreciable symptom relief in about 33% of all cases; the NNT is therefore 3.

I think we need to know how often the pain goes away without treatment before we can compute the NNT here. NNT always depends on quality of the drug and likelihood of the defined endpoint without the drug. For example, if 10% of patients get better by themselves, then the NNT would be slightly bigger than 4. AxelBoldt 22:43, 30 May 2005 (UTC)

I simply added a number from my own experience. I should have sourced it from the Bandolier pain site. The NNT is not affected by spontaneous improvement. JFW | T@lk 08:32, 31 May 2005 (UTC)

From reading the Bandolier article, I believe NNT is affected by spontaneous improvement; in fact their first migraine example explicitely compares a placebo control group's outcome with the treatment group's outcome. With treatment 5% recur, without treatment 30% recur, so the NNT is 1/(30%-5%)=4. AxelBoldt 19:58, 31 May 2005 (UTC)

Shall we find a better example? It seems you're correct about the spontaneous recovery rate, but spontaneous recovery rate is subtracted from the response in the treatment group before calculating the NNT. JFW | T@lk 01:49, 2 Jun 2005 (UTC)