What techniques might be used to harness placebo effects in non-malignant pain? A literature review and survey to develop a taxonomy
Felicity L Bishop, Beverly Coghlan, Adam WA Geraghty, Hazel Everitt, Paul Little, Michelle M Holmes, Dionysis Seretis, George Lewith
Objectives: Placebo effects can be clinically meaningful but are seldom fully exploited in clinical practice. This review aimed to facilitate translational research by producing a taxonomy of techniques that could augment placebo analgesia in clinical practice. Design: Literature review and survey. Methods: We systematically analysed methods which could plausibly be used to elicit placebo effects in 169 clinical and laboratory-based studies involving non-malignant pain, drawn from seven systematic reviews. In a validation exercise, we surveyed 33 leading placebo researchers (mean 12 yearsâ€™ research experience, SD 9.8), who were asked to comment on and add to the draft taxonomy derived from the literature. Results: The final taxonomy defines 30 procedures that may contribute to placebo effects in clinical and experimental research, proposes 60 possible clinical applications and classifies procedures into five domains: the patientâ€™s characteristics and belief (5 procedures and 11 clinical applications), the practitionerâ€™s characteristics and beliefs (2 procedures and 4 clinical applications), the healthcare setting (8 procedures and 13 clinical applications), treatment characteristics (8 procedures and 14 clinical applications) and the patientâ€“practitioner interaction (7 procedures and 18 clinical applications). Conclusion: The taxonomy provides a preliminary and novel tool with potential to guide translational research aiming to harness placebo effects for patient benefit in practice.