therapies by all individuals aged 18 and older. They observed that 68 percent of all respondents had used as least one CAM therapy during the course of their lives. Lifetime use steadily increased with age across all age cohorts. Specifically, individuals in the pre-baby boom cohort (i.e., older than age 58 years at the time of the survey) had a 30 percent incidence of CAM therapy use by the age of 33; 5 of 10 baby boomers had used one or more CAM therapies by age 33, and 7 of 10 individuals born after the baby boom reported the use of some type of CAM therapy by age 33. It was also noted that prior use of any CAM therapy was an excellent predictor of current use. Among the respondents who had ever used a CAM therapy, roughly half continued to use a CAM therapy many years later (during the interval of the survey).

These analyses also documented the fact that the rate of use of all but 4 of the 20 most commonly used complementary therapies increased in frequency beginning in the 1960s. During the decades of the 1970s, 1980s, and 1990s, the use of particular CAM therapies increased at higher rates than the use of others. For instance, the 1970s witnessed large increases in the rates of use of herbal medicine, imagery, energy healing and biofeedback, whereas in the 1980s the rates of use of massage therapy and naturopathy increased most rapidly.

Kessler and colleagues (2001) mention that “from an historical perspective, data from 1998 may not necessarily represent a consistent trend of increased use of CAM therapies, but rather a distinct peak in a long trend of constant fluctuation in complementary and alternative medicine use by the American public.” They refer to previous peaks of CAM use such as survey data from the 1920s and 1930s indicating high rates of use of “unconventional” therapies and government statistics from 1900 documenting large numbers of registered “alternative” practitioners. Kessler et al. conclude that the recent high rates of CAM use may in fact be demonstrating a resurgence of CAM use after a period of diminished use during the 1940s and 50s. Even so, use of CAM therapies in recent years by a large proportion of the U.S. population is seen as a result of a historical trend that began at least 50 years ago. Moreover, this trend suggests a continuing demand for CAM therapies that will affect health care delivery for the foreseeable future.

Other factors associated with CAM therapy use that further this hypothesis include the observation that CAM therapies are used predominantly for the treatment of chronic disease, which, as mentioned above, accounts for an increasing fraction of the U.S. healthcare burden (Astin, 1998). In addition, an estimated one-third of CAM therapy use is attributed to disease prevention and health promotion (Eisenberg et al., 1993, 1998). These patterns parallel trends in U.S. society to promote disease prevention and to encourage health promotion, especially among those in the baby