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Complementary & Alternative Medicine

Guide to locating research evidence for complementary and alternative therapies.

Clinical Practice Guidelines

Evidence-Based CAM

The very premise that CAM can be "evidence-based" is not without controversy. Some argue that evidence-based complementary and alternative medicine is a contradiction in terms1, and complementary and alternative therapies are inherently incompatible with evidence-based medicine2. Others claim that CAM can be considered evidence-based if the supporting research adheres to the same rigorous and standardized methods as conventional medicine3.

Nevertheless patients and consumers continue to use and seek out information about CAM modalities4-6, while facing an information landscape that plagued by limited empirical research that is often misleading or of low quality7,8.  As such, to best serve patients and clients, it is critically important for practitioners to understand the relationship between CAM and conventional medicine, the methodological issues that CAM research faces, and how to evaluate the potential value and pitfalls of CAM therapies. 

The Critical Appraisal Resources found on this guide will offer general information and tools about critically appraising health evidence, but also consider exploring the resources below, which specifically focus on the conundrums, controversies and philosophies surrounding evidence-based complementary and alternative medicine.  

Resources: Understanding CAM in the Context of Evidence-Based Medicine


  1. Angell, M., & Kassirer, J. P. (1998). Alternative medicine—The risks of untested and unregulated remedies. The New England Journal of Medicine, 339(12), 839–841.

  2. Tonelli, M. R., & Callahan, T. C. (2001). Why alternative medicine cannot be evidence-based. Academic Medicine: Journal of the Association of American Medical Colleges, 76(12), 1213–1220.

  3. Yamey, G. (2000). Can complementary medicine be evidence-based? Western Journal of Medicine, 173(1), 4–5. 

  4. Clarke, T. C., Barnes, P. M., Black, L. I., Stussman, B. J., & Nahin, R. L. (2018). Use of yoga, meditation, and chiropractors among U.S. adults aged 18 and over (No. 325; NCHS Data Brief). National Center for Health Statistics.

  5. Barnes, L. A. J., Barclay, L., McCaffery, K., & Aslani, P. (2019). Complementary medicine products information-seeking by pregnant and breastfeeding women in Australia. Midwifery, 77, 60–70.

  6. Scarton, L. A., Del Fiol, G., Oakley-Girvan, I., Gibson, B., Logan, R., & Workman, T. E. (2018). Understanding cancer survivors’ information needs and information-seeking behaviors for complementary and alternative medicine from short- to long-term survival: A mixed-methods study. Journal of the Medical Library Association : JMLA, 106(1), 87–97.

  7. Ng, J. Y., Jomy, J., & Vacca, A. (2022). Evaluation of the quality of online patient information at the intersection of complementary and alternative medicine and hypertension. Clinical Hypertension, 28(1), 9.

  8. Ng, J. Y., Zhang, C. J., & Ahmed, S. (2021). Dietary and herbal supplements for fatigue: A quality assessment of online consumer health information. Integrative Medicine Research, 10(4), 100749.