Framework for evidence synthesis of Traditional, Complementary and Integrative Medicine systems incorporating context and complexity, illustrated by the example of homeopathy

BackgroundEvidence synthesis for whole medical systems is challenging. This paper reviews, and provides a framework for, evidence synthesis of Traditional, Complementary and Integrative Medicine (TCIM) systems incorporating context and complexity. There are currently no systematic reviews that comprehensively evaluate homeopathy as a patient-centered whole medical system in accordance with contemporary scientific standards. A systematic review program on the effects of homeopathic preparations in various clinical indications is used as a practical illustration of the proposed framework.Proposed solutionA systems perspective considers the patient as a complex system of interconnected regulative subsystems embedded in a complex environment, and disease as a dysregulation of the dynamic adaptive state of the organism. Most TCIM systems, including homeopathy, aim to stimulate regulative systems and their functions to regain homeostasis, rather than to structurally change something within the organism. The consequences of these principles for the approach to evidence synthesis are explored, and its implementation is illustrated by the systematic review program on the effects and effectiveness of homeopathy.ResultsA systems perspective requires taking into account a plurality of evidence sources, including in particular ‘real-world’ clinical data, which is why the systematic review program will include non-randomized prospective comparative studies (NRSIs) as well as RCTs. A patient advocate will be involved during the entire research program and input from patients with living experience with homeopathy for the clinical indication concerned will be incorporated in each of the systematic reviews. DiscussionRCT and NRSI evidence on homeopathic preparations for a range of clinical indications will be synthesised. A limitation, from a complex systems perspective, is that the implication of these findings will still need to be framed within the broader context of the existing state of knowledge. An ‘evidence eco-system’, that includes complementary sources of information, will be required to inform decisions. ConclusionsEvidence synthesis of TCIM systems can move beyond conventional approaches by framing evidence within its complexity and context, together with real-world data and patient perspectives. This approach entails methodological challenges and will require gap analyses to guide future research and improve applicability for public health and patient care.