The World Health Organization (WHO) deﬁ nes complementary and alternative medicine (CAM) as a ‘broad set of health care practices that are not part of that country’s own tradition and are not integrated into the dominant health care system’ (WHO 2000). CAM includes a wide range of therapies, products and practices, such as (i) visits to alternative health care practitioners, for example, acupuncturist, homeopath, and healer; (ii) use of herbal medicine and dietary supplements; and (iii) self-help practices, for example, meditation, yoga, prayer and relaxation techniques. Traditional health care systems, for example, traditional Chinese medicine, Indian Ayurveda, homeopathy and naturopathy combine several of these therapies in their treatment regimens. CAM is heterogeneous, and this is exempliﬁ ed by the national legal status and regulation of alternative health care providers and the terminology used. In most countries, CAM is not covered by national insurance systems, and users pay almost all CAM-related costs out of their own pocket (Thomas et al. 2001). Although the efﬁ cacy of CAM is a controversial issue that generates considerable professional and public debate a high proportion of the general population and the chronically ill turn to CAM (Harris et al. 2012).