Occurrence and co-occurrence of types of complementary and alternative medicine use by age, gender, ethnicity, and education among adults in the United States: the 2002 National Health Interview Survey (NHIS).

BACKGROUND: There are widespread assumptions that a large proportion of American adults use a variety of complementary and alternative medicine (CAM) therapies. The goal of this study is to explore the clustering or linkages among CAM categories in the general population. Linkset analysis and data from the 2002 National Health Interview Survey (NHIS) were used to address two specific aims. First, the dominant linkages of CAM categories used by the same individual were delineated, and population estimates were generated of the percentage of American adults using different linksets of CAM categories. Second, it was determined whether dominant linkages of CAM modalities differ by age, gender, ethnicity, and education.
METHODS: Linkset analysis, a method of estimating co-occurrence beyond chance, was used on data from the 2002 NHIS (N = 29,862) to identify possible sets of CAM use.
RESULTS: Most adults use CAM therapies from a single category. Approximately 20% of adults combined two CAM categories, with the combination of mind-body therapies and biologically based therapies estimated to be most common. Only 5% of adults use therapies representing three or more CAM categories. Combining therapies across multiple CAM categories was more common among those 46-64, women, whites, and those with a college education.
CONCLUSIONS: The results of this study allow researchers to refine descriptions of CAM use in the adult population. Most adults do not use a wide assortment of CAM; most use therapies within a single CAM category. Sets of CAM use were found to differ by age, gender, ethnicity, and education in ways consistent with previous research.