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Complementary & Alternative Medicine

Guide to locating research evidence for complementary and alternative therapies.


Defining the Field(s)

Complementary and alternative medicine (CAM) covers a diverse group of systems and practices that are considered to fall outside of 'conventional medicine'. The terms complementary, alternative, integrative, natural or holistic are often used interchangeably in reference to healthcare.  The NIH's National Center for Complementary and Integrative Health1 has set forth the following definitions:


"a non-mainstream approach is used together with conventional medicine"


"brings conventional and complementary approaches together in a coordinated way"


"a non-mainstream approach is used in place of conventional medicine"


Locating CAM Evidence

Locating high quality research evidence regarding the effectiveness of CAM and integrative therapies can be difficult.  In part because of barriers to research on the many diverse interventions that fall under the CAM umbrella2, but also in part due to questions and ambiguities about what 'high quality' evidence looks like for CAM.  There are tensions around the relationship between CAM/integrative therapies and the paradigm of evidence-based medicine in a biomedical model of care, which leans heavily on the evidence from randomized controlled trials3.  For more information and suggested readings, see the section of this guide titled Evidence-Based Practice & CAM.



1. National Center for Complementary and Integrative Health. Complementary, Alternative, or Integrative Health: What’s In a Name? (2021, April). Retrieved March 24, 2022, from

2. Veziari, Y., Leach, M. J., & Kumar, S. (2017). Barriers to the conduct and application of research in complementary and alternative medicine: a systematic review. BMC Complementary and Alternative Medicine, 17(1), 166.

3. Curtis, PC. Evidence-Based Medicine & Complementary & Alternative Therapies. In S. Gaylord, S. Norton, P. Curtis (Eds.), The Convergence of Complementary, Alternative & Conventional Health Care: Educational Resources for Health Professionals. University of North Carolina at Chapel Hill, Program on Integrative Medicine, 2004.