Trends in evidence based medicine for herbal remedies and media coverage.

• Author: Bubela, Tania

Complementary and Alternative Medicines [CAM] are interventions that are not widely taught in medical schools and are not part of the usual arsenal of treatments and medications recommended and prescribed by physicians and available in hospitals. (1) CAM is big business ($30 billion in the US) with aggressive marketing. Their use in Europe and North America is increasing significantly. (2) For example, a 1998 phone survey of 1539 adults found that 42.1% in the United States had used at least one CAM within a twelve month period and that use had increased since 1990; the most used treatments were herbal medicine, massage, megavitamins, self-help groups, folk remedies, energy healing and homeopathy. (3) In 2003, 20% of all Canadians visited a CAM practitioner, up from 15% in 1994/5. (4)

Users of CAM are more likely to have higher education levels and report lower health status. (5) Common health problems treated with CAM are anxiety, back problems, chronic pain, and urinary tract problems. Use of CAM is dependent, not on dissatisfaction with conventional medicine as it is most commonly used in association with conventional medicine, but on philosophical orientations towards health and life, such as feminism, spirituality, and personal growth. (6) Other studies suggest that CAM use allows patients and consumers greater control over their health and a level of self-empowerment. (7) For these reasons, it has become increasingly important to understand the nature and impact of popular representations of CAM in this context.

The combination of educated and self-empowered users of CAM suggests a high degree of reliance on information sources outside of mainstream medical practitioners. Not surprisingly, coverage in sources including newspapers, television, magazines, other media, and the internet has increased to meet the demand for information. A vast quantity of information of varying quality exists in the media and on the internet. (8) There are concerns, however, that the media and internet provide too rosy a picture of CAM (9) and downplay adverse reactions to CAM, which can be dangerous and potentially fatal. (10) Such coverage augments the common misperception that CAM is natural and therefore, less harmful than conventional medical treatments. (11) Indeed, Barnes et al. (1998) found that users of CAM were less likely to report adverse effects than users of over-the-counter medicines. (12) These factors suggest that significant improvements need to be made to knowledge translation mechanisms for the public, healthcare professionals, and policy makers.

The response of the medical and scientific community has been an increasing interest in CAM issues. There has been an increase in the number and proportion of clinical trials of CAM, which suggests a trend toward an evidence-based approach. The cumulative number of clinical trial articles indexed on MEDLINE, however, remains small (0.4%), and more high-quality original research is needed. (13) Further, the proportion of those articles on CAM indexed as clinical trial-type studies is 2.1%, but rising. (14)

The lack of clinical trials may be due to a number of factors. There may be little incentive for commercial manufacturers of CAM products to run expensive clinical trials. However, the recent move to evidence-based health claims for CAM labeling and advertising in Canada (15) may drive an increase in CAM clinical trials in that country.

Some authors have suggested that there may be a publishing bias from mainstream medical journals during peer review or editorial process, in either rejecting CAM studies outright or favouring CAM studies with negative results. (16) However, others suggest that most CAM studies may simply be of insufficient quality to be published in high impact factor medical journals. (17) At least 50% of CAM...