Computer says yesBMJ 2008; 336 doi: https://doi.org/10.1136/bmj.39527.440417.59 (Published 27 March 2008) Cite this as: BMJ 2008;336:724
- Des Spence, general practitioner, Glasgow
In the west of Scotland, where it rains continually, many people have red hair and freckles. You could conclude, perhaps, that high rainfall causes red hair and freckles. But mere association is not causation, however plausible the link might seem. This is the fundamental flaw within all observational data: that an unknown alternative explanation (confounding factor) is responsible.
Often I sit looking at lab results on the computer. A message …