Long-term trends in the use of complementary and alternative medical therapies in the United States.

BACKGROUND: Although recent research has shown that many people in the United States use complementary and alternative medical (CAM) therapies, little is known about time trends in use. OBJECTIVE: To present data on time trends in CAM therapy use in the United States over the past half-century. DESIGN: Nationally representative telephone survey of 2055 respondents that obtained information on current use, lifetime use, and age at first use for 20 CAM therapies. SETTING: The 48 contiguous U.S. states. PARTICIPANTS: Household residents 18 years of age and older. MEASUREMENT: Retrospective self-reports of age at first use for each of 20 CAM therapies. RESULTS: Previously reported analyses of these data showed that more than one third of the U.S. population was currently using CAM therapy in the year of the interview (1997). Subsequent analyses of lifetime use and age at onset showed that 67.6% of respondents had used at least one CAM therapy in their lifetime. Lifetime use steadily increased with age across three age cohorts: Approximately 3 of every 10 respondents in the pre-baby boom cohort, 5 of 10 in the baby boom cohort, and 7 of 10 in the post-baby boom cohort reported using some type of CAM therapy by age 33 years. Of respondents who ever used a CAM therapy, nearly half continued to use many years later. A wide range of individual CAM therapies increased in use over time, and the growth was similar across all major sociodemographic sectors of the study sample. CONCLUSIONS: Use of CAM therapies by a large proportion of the study sample is the result of a secular trend that began at least a half century ago. This trend suggests a continuing demand for CAM therapies that will affect health care delivery for the foreseeable future.