Herb and supplement use in the US adult population.

BACKGROUND: Research on the scope of use and factors associated with herbal medicine use is limited.
OBJECTIVES: The aims of this work were to assess national usage patterns, reasons for use, and the perceived efficacy of herbal products and dietary supplements.
METHODS: This was a secondary analysis of the complementary and alternative medicine (CAM) supplement to the 2002 National Health Interview Survey (NHIS), conducted by the National Center for Health Statistics (NCHS). Participants were asked whether they had used natural herbs for their own health and treatment. Those who responded yes were compared with those who responded no. Supplement users were asked whether they had used any of 36 specific herbs or nonherbal dietary supplements (eg, glucosamine, fish oil, bee pollen), how important the use of CAM treatment was to them, whether they had seen a CAM provider, and whether they had informed a conventional medical provider about their use. NCHS weights, derived from Decennial Census data, were used to calculate national prevalence estimates. Group comparisons of herbal use were conducted with the Wald x(2) test.
RESULTS: A total of 31,044 adults participated in the 2002 NHIS CAM survey; 632 were omitted from analyses due to incomplete information. In all, 5787 adults said they had used herbs or supplements during the previous 12 months, of whom 57.3% said they used these products to treat specific conditions. Based on these responses, an estimated approximately 38.2 million adults in the United States used herbs and supplements in 2002. More than half of all users said that herbs and natural products were important to their health and well-being. Use rates were higher for women than men (21.0% vs 16.7%; P < 0.001); adults aged 45 to 64 years (P < 0.001 vs other age groups); those of multiple races (32.2%), Asians (24.6%), or American Indians or Alaskan natives (21.9%) rather than whites (19.1%) or blacks (14.3%) (effect of race, P < 0.001); residents of the western United States (effect of region, P < 0.001), and college graduates (25.3% vs 10.4% among those who did not graduate high school; effect of education, P < 0.001). Only 33.4% told a conventional health care provider about their herb or supplement use use.
CONCLUSION: Herb and natural supplement use was widespread in the US adult population in 2002, according to data from the NHIS CAM survey, despite the fact that few participants informed their conventional health care providers about such use.