Evidence based medicine: does it make a difference?

Editor—Both the editorial by Del Mar et al and the paper by Straus et al raise important points that must be considered if both medical students and doctors are to be trained successfully in evidence based practice.¹,²

Del Mar et al say that epidemiology and statistics are repellent to many doctors. In our experience, neither topic is repellent. However, feedback from medical students at the end of our clinical epidemiology course has consistently raised concerns about the ability of students without A level mathematics (a higher school qualification in the United Kingdom) to cope with the biostatistics component of the course, although no complex mathematical calculations are required. We therefore examined this empirically by comparing the exam performance of such students with that of their peers with A level mathematics and did not find any evidence that they were any less competent, at least as assessed by a written exam paper entailing critical appraisal (-1.1% difference in means for students without v those with A level mathematics, 95% CI -3.1% to 0.8%, P = 0.20 based on 498 first year medical students).³

We believe that some students experience “numerophobia”—a perceived and disproportionate fear of numbers and simple mathematical manipulation. Interestingly, new cohorts of students have not raised this issue since we started to present these data to them at the beginning of our course.

Other evidence shows that this problem is also common among doctors.⁴ Some doctors react antagonistically to evidence based medicine because it ignores the individual patient, takes too long, often lacks evidence, and is too much like “cookbook” medicine. Numerophobia should be added to this list and consideration be given to how to overcome it.