Utilization of complementary and alternative medicine by United States adults - Results from the 1999 National Health Interview Survey

OBJECTIVE. To measure utilization of complementary and alternative medicine (CAM) by US adults. METHODS. We analyzed data from the 1999 National Health Interview Survey (NHIS), which covers the noninstitutionalized civilian US population. Information on 12 types of CAM use in the past 12 months was obtained from 30,801 respondents aged IS years and older. Statistical analyses were performed using the SUDAAN software package to account for the complex sample design of the NHIS. RESULTS. An estimated 28.9% of US adults used at least one CAM therapy in the past year. The three most commonly used therapies were spiritual healing or prayer (13.7%), herbal medicine (9.6%), and chiropractic therapies (7.6%). The use of CAM was most prevalent among women, persons aged 35 to 54 years, and persons with an educational attainment of greater than or equal to 16 years. The overall CAM use was higher for white non-Hispanic persons (30.8%) than for Hispanic (19.9%) and black non-Hispanic persons (24.1%). Although the use was higher for persons who had health insurance than for those who did not, the difference was not statistically significant after adjusting for age, gender and educational attainment. Compared with nonusers, CAM users were more likely to use conventional medical services. CONCLUSIONS. Estimates of CAM use in this nationally representative sample were considerably lower than have been reported in previous surveys. Most CAM therapies are used by US adults in conjunction with conventional medical services.