The use of alternative or complementary therapies have increased over the past years with more than one-third of people using at least one form of alternative medicine. Alternative or complementary therapies include treatments such as biofeedback, yoga, hypnosis, acupuncture, chiropractic care, and high-dose vitamins.

Researchers in Boston compared the results of their own survey taken in 1997 to the National Health Interview Survey taken in 2002. Results showed the total number of Americans using alternative or complementary therapies remained fairly stable at 72 million between 1997 and 2002. However, the types of therapies used have changed. There was a 50-percent increase in the use of herbal supplements and a 40-percent increase in the use of yoga.

Thus researchers recommend more studies to help determine the safety and efficacy of these therapies.