December 9, 2001

Evidence-Based Medicine

By JACK HITT

hen visiting our family doctor, most of us feel secure in the belief that modern science has purged medicine of such practices as cupping and bloodletting. But according to a recent article in the journal Patient Care, ‘‘Some experts estimate that only 20 percent of medical practices are based on rigorous research evidence.’’ The rest are based on what has been published in books repeatedly without independent testing – or what doctors have always said should work. In other words, it’s a kind of folklore.

A revolution is erupting in the wards of practical medicine these days, one defined recently by The British Medical Journal as ‘‘the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients.’’ The revolution is called evidence-based medicine, or E.B.M., and many traditional treatments are being run through the machinery of the scientific method – and being found wanting.

One common E.B.M. approach is meta-analysis: collating data from far-flung studies to come up with a definitive answer to a medical question. Such studies are overthrowing some conventional wisdom. Mammogram screenings? They don’t save lives. Remember the placebo effect? It doesn’t exist. E.B.M. is also credited with validating some simple cures. Most people know that if you have a heart attack, you should immediately take an aspirin. Thank an E.B.M. study for proving that this works.

After colds, the second-most-common reason for a visit to the doctor is lower-back pain. The ‘‘treatment’’ has always been bed rest. Why? Because, as a recent article explained, ‘‘The notion that rest is therapeutic and will relieve pain dates back to Hippocrates.’’ But now that E.B.M. studies have used science instead of oral tradition to test this notion, they have found that bed rest ‘‘may delay return to functional status.’’ What works better? Light exercise and getting back on your feet. This past June, the Agency for Healthcare Research and Quality integrated the no-bed-rest approach into its guidelines. This new standard of care, which will probably save billions of dollars in unnecessary sick leave, marks the end of 2,400 years of misguided treatment.

E.B.M. is yet another idea that can be credited to the computer revolution. Doctors have long known that they learn very little after med school when their exhausting schedules and the baffling profusion of 4,000 monthly professional journals make it nearly impossible to keep up with innovations in treatment. The E.B.M. movement began when six doctors in Canada came up with the idea of skimming the most dependable studies and crunching the results into an accessible, reliable database.

Indeed, in the wake of E.B.M., journals are filling with terms that sound almost anthropological to describe longstanding treatments: ‘‘local custom,’’ ‘‘witch-doctoring,’’ ‘‘myth.’’ Or as one article this fall put it, ‘‘This process of examining beliefs that have been based primarily on teaching and empirical experience rather than evidence has been compared to stripping the curtain away from the Wizard of Oz to reveal an ordinary man.

ALL INFORMATION, DATA, AND MATERIAL CONTAINED, PRESENTED, OR PROVIDED HERE IS FOR GENERAL INFORMATION PURPOSES ONLY AND IS NOT TO BE CONSTRUED AS REFLECTING THE KNOWLEDGE OR OPINIONS OF THE PUBLISHER, AND IS NOT TO BE CONSTRUED OR INTENDED AS PROVIDING MEDICAL OR LEGAL ADVICE.  THE DECISION WHETHER OR NOT TO VACCINATE IS AN IMPORTANT AND COMPLEX ISSUE AND SHOULD BE MADE BY YOU, AND YOU ALONE, IN CONSULTATION WITH YOUR HEALTH CARE PROVIDER.