Ask most research physicians how a profession can advance, and they will talk about the model of â€œevidence-based medicineâ€â€”the idea that nothing ought to be introduced into practice unless it has been properly tested and proved effective by research centers, preferably through a double-blind, randomized controlled trial. But, in a 1978 ranking of medical specialties according to their use of hard evidence from randomized clinical trials, obstetrics came in last. Obstetricians did few randomized trials, and when they did they ignored the results. . . . Doctors in other fields have always looked down their masked noses on their obstetrical colleagues. Obstetricians used to have trouble attracting the top medical students to their specialty, and there seemed little science or sophistication to what they did. Yet almost nothing else in medicine has saved lives on the scale that obstetrics has. In obstetrics . . . if a strategy seemed worth trying doctors did not wait for research trials to tell them if it was all right. They just went ahead and tried it, then looked to see if results improved. Obstetrics went about improving the same way Toyota and General Electric did: on the fly, but always paying attention to the results and trying to better them. And it worked.
Is there a biological metaphor for this? A perfectly good method (say, randomized trials) is introduced into the population of medical research methods. Unfortunately for those in poor health, the new method becomes the tool of a dogmatic tendency, which uses it to reduce medical progress.