Medicine based on scientific evidence versus medicine based on evangelical marketing

Abstract

S acceptance of medical practice should require evidence that such practice improves health outcomes.1 Vaccines are sanctioned only after they are proven to prevent morbidity and mortality and to be safe and reasonably cost efficient. Antibiotics must not only kill microbes, but also make sick people well and be relatively free of adverse effects. To ensure efficacy and safety, national governments, including our own, have independently investigated new therapeutic modalities, passed laws, and instituted regulatory agencies such as the Food and Drug Administration. Such measures, while a nuisance and often costly, do protect the populace and the medical community from evangelical crusades such as those of the laetrile enthusiasts of the 1960s. These protections are not ubiquitous in space or in time; neither are they totally comprehensive in our society today. Unproven treatments, such as chelation therapy for atherosclerosis and herbal cures for multiple illnesses, abound but are confined to the fringe of medicine by the general integrity of scientific peer review and the social watchdog function of professional societies like the American Medical Association, the American College of Cardiology, and the American Heart Association. Much diagnostic testing has escaped from legal and social regulation during the past 20 years and has worked its way into the realm of cleverly marketed self-application. Doctors order and patients refer themselves for tests in order to discover early and hidden pathology and then to arrive at effective treatment before they fear that it will be too late. Much of this testing and the resultant interventions have questionable scientific validity, although some, after careful scientific scrutiny, do prove useful in reducing mortality and morbidity. Mammographic screening for breast cancer presents an interesting lesson in this phenomenon.2–4 Both unscrupulous marketers and well-meaning enthusiasts spurred the early interest in this screening procedure to detect early pathology and to prevent mortality. This interest prompted the government to investigate the efficacy of mammography in randomized controlled studies, 6 of which have provided proof of its worth, not only for detecting tumors and predicting outcomes, but also for preventing cancer deaths in women over the age of 50 and in younger subgroups at high risk. Prostate-specific antigen testing and radiographic screening for lung cancer have experienced less spectacular scientific validation but are frequently used with or without physician referrals. In 1991, headlines such as the following began to appear in local newspapers: “New Procedure can Speed Detection of Heart Disease.”5 At that time, there was no supportive scientific literature regarding the value of the new test, electron beam computed tomographic scanning (EBCT), for predicting heart disease events, to say nothing about its usefulness in improving outcome. In 1993, the EBCT scanner users’ organization adapted a policy of direct marketing to the American public. These developments spurred interest from venture capital firms, small marketing operations, and university medical centers strapped for sources of income. This new economic interest inspired the flurry of coronary calcium screening programs that we are currently experiencing and which promises to grow and mutate into other varieties of unproven radiographic self-diagnosis. Some coronary calcium screening centers now offer lung cancer screening and a few centers have expanded to “full body examinations,” which are touted as high-tech physical examinations capable of finding multiple pathologies. To validate their practices, coronary calcium screeners compiled calcium score databases and followed participants for coronary events. These research subjects rarely knew they were a part of a study and were usually not asked to sign consent forms verifying that they had agreed to participate in the evaluation of an investigational test. The calcium screeners, many of them university academicians, often drew salary from the proceeds of scanning and told participants that the test was already proven to predict heart attacks and death. In 1999, they founded what they call a professional society, “The Society of Atherosclerosis Imaging” of which Dr. Hecht is the president. We must never believe that economic greed is the major factor motivating the spread of coronary calcium screening adventures. The primary leadership of the calcium movement was not clever Madison Avenue charlatans nor marketers for the imaging industry, From the Harbor UCLA Medical Center Research and Education Institute, Torrance, California. Manuscript received and accepted March 30, 2001. Address for reprints: Robert Detrano, MD, PhD, Harbor-UCLA Medical Center, Division of Cardiology, 1124 West Carson Street, Blg. RB-2, Torrance, California 90502-2064. E-mail: rdetrano@ rei.edu.