Trends in use of complementary and alternative medicine by US adults: 1997-2002.

CONTEXT: Complementary and alternative medicine (CAM) use by US adults increased substantially between 1990 and 1997, yet little is known about more recent trends.

OBJECTIVE: Compare CAM therapy use by US adults in 2002 and 1997.

DESIGN: Comparison of two national surveys of CAM use by US adults: (1) the Alternative Health/Complementary and Alternative Medicine supplement to the 2002 National Health Interview Survey (NHIS, N = 31,044) and (2) a 1997 national survey (N = 2055), each containing questions about 15 common CAM therapies.

MAIN OUTCOME MEASURES: Prevalence, sociodemographic correlates, and insurance coverage of CAM use.

RESULTS: The most commonly used CAM modalities in 2002 were herbal therapy (18.6%, representing over 38 million US adults) followed by relaxation techniques (14.2%, representing 29 million US adults) and chiropractic (7.4%, representing 15 million US adults). Among CAM users, 41% used two or more CAM therapies during the prior year. Factors associated with highest rates of CAM use were ages 40-64, female gender, non-black/non-Hispanic race, and annual income of dollar 65,000 or higher. Overall CAM use for the 15 therapies common to both surveys was similar between 1997 and 2002 (36.5%, vs. 35.0%, respectively, each representing about 72 million US adults). The greatest relative increase in CAM use between 1997 and 2002 was seen for herbal medicine (12.1% vs.18.6%, respectively), and yoga (3.7% vs. 5.1%, respectively),while the largest relative decrease occurred for chiropractic (9.9% to 7.4%, respectively).

CONCLUSIONS: The prevalence of CAM use has remained stable from 1997 to 2002. Over one in three respondents used CAM in the past year, representing about 72 million US adults.