Prevalence of Use of Traditional, Complementary and Alternative Medicine by the General Population: A Systematic Review of National Studies Published from 2010 to 2019.

Traditional, complementary and alternative medicine (TCAM) includes products (e.g. herbal medicines, dietary supplements) and therapies/practices (e.g. chiropractic, acupuncture), and is a popular healthcare choice for many people. This study systematically reviewed national surveys of TCAM use around the world. We identified studies carried out in 14 different countries and one continent (Europe) on the extent of use of TCAM in the general population. TCAM use was found to be substantial, ranging from 24 to 71.3% in different countries. National surveys use different methods and different survey questionnaires. Some studies did not publish the survey questionnaire that they used and/or did not describe the types of TCAM included in the study. This means that it is not possible to compare the results between countries or to do further data analysis. For example, the survey questions from different countries asked people if they had 'used' or 'seen a practitioner' for a specific therapy, such as homeopathy. These questions look similar, but could elicit different answers from people. This means that the answers to these questions cannot be pooled together or compared directly. Also, some studies collected information on use of a category of TCAM products, such as herbal medicines, but other studies collected information on use of specific herbal medicines, such as St John's wort. New surveys of the extent of use of TCAM should provide full information on the types of TCAM products, practices and therapies included in the study and consider collecting comprehensive information on use of specific TCAM products, practices and therapies.