Aditya Bardia, Nicole L. Nisly, M. Bridget Zimmerman, Brian M. Gryzlak, Robert B. Wallace

To examine the extent to which US adults use herbs (herbal supplements) in accordance with evidence-based indications. The Alternative Health supplement of the 2002 National Health Interview Survey (NHIS) is part of an annual, nationally representative survey of US adults. It contains data on adults' use of the 10 herbs most commonly taken to treat a specific health condition in the past year (January 1 to December 31, 2002). The Natural Standard database was used to formulate evidence-based standards for herb use. These standards were applied to the NHIS data to identify groups of people who used herbs appropriately and inappropriately, using a multivariable logistic regression model. Of the 30,617 adults surveyed, 5787 (18.9%) consumed herbs in the past 12 months; of those, 3315 (57.3%) used herbs to treat a specific health condition. Among people who used only 1 herb (except echinacea and ginseng), approximately one third used it consonant with evidence-based indications. Women and people with a college education were more likely to use herbs (with the exception of echinacea) concordant with scientific evidence. Adults younger than 60 years and black adults were significantly less likely to use herbs (with the exception of echinacea) based on evidentiary referents than their counterparts. However, for echinacea users, no significant differences were detected. Roughly two thirds of adults using commonly consumed herbs (except echinacea) did not do so in accordance with evidence-based indications. Health care professionals should take a proactive role, and public health policies should disseminate evidence-based information regarding consumption of herbal products.