Changes in herb and dietary supplement use in the U.S. adult population: a comparison of the 2002 and 2007 National Health Interview Surveys.

BACKGROUND: Past national surveys indicate that use of herbs and dietary supplements rose rapidly in the United States during the 1990s and early 2000s. Additional research is needed to determine whether this growth rate and associated patterns of use have persisted over time.

OBJECTIVES: The objectives of this study were: (1) to assess population and subpopulation changes in rates of herb and supplement use; and (2) to assess changes in rates of disclosure of herb and supplement use to conventional medical providers.

METHODS: This study used data from the 2002 (n = 30,427) and 2007 (n = 22,657) Adult Complementary and Alternative Medicine File to the National Health Interview Survey (NHIS). Weighted group and subgroup comparisons used the Wald χ(2) tests to compare differences in herb and supplement use between 2002 and 2007.

RESULTS: The number of adults in the United States that ever used herbs or supplements grew slightly, from 50.6 million in 2002 to 55.1 million in 2007. However, the proportion of adults who reported use of herbs or supplements in the past 12 months dropped significantly: from 18.9% in 2002 to 17.9% in 2007 (P < 0.05). Subpopulation comparisons revealed that younger adults were less likely to use herbs and supplements in 2007 (17.6%) than in 2002 (20.0%), whereas older adults (ie, those aged ≥65 years) were more likely to do so (19.5% in 2007 vs. 13.2% in 2002). Racial and ethnic minorities also reported a significant decline in recent use. The proportion of respondents that disclosed herb or supplement use to their physician or another conventional medical professional rose, from 33.4% in 2002 to 45.4% in 2007. However, <1% of recent herb and supplement users disclosed this use to their pharmacist. Limitations of this research are that the 2 national data sets were not directly comparable and that questionnaires in the 2 surveys assessed were not identical.

CONCLUSIONS: Herbal preparations and dietary supplements remain popular in the United States, but the user population and patterns of use are changing. Ongoing surveillance of this health behavior is a public health priority.