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Background: The magnitude of placebo effects from physical and psychological 'sham' is unknown but could impact efficacy trials and treatment understanding. To quantify placebo effects, this systematic review of three‐armed randomised controlled trials (RCTs) of physical and psychological interventions for pain compared outcomes in 'sham' control intervention and non‐exposure arms. Methods: RCTs with treatment, 'sham' control intervention, and non‐exposure groups were included, enrolling adults with any pain. A protocol was pre‐registered (PROSPERO: CRD42023413324), and twelve databases searched from 2008 to July 2023. Trial methods and blinding were analysed descriptively and risk of bias assessed. Meta‐analysis of pain measures at short‐, medium‐ and long‐term was performed with random‐effects models of standardised mean differences (SMD).Studies were sub‐grouped according to control intervention type. Results: Seventeen RCTs were included. The average short‐term placebo effect was small (0.21 SMD, 0.1–0.33 95% CI, p = 0.0002, 1440 participants). It showed no heterogeneity (Tau2 = 0.1, I2 = 11%, p = 0.3), preventing meta‐regression analyses of effect modifiers. However, sub‐group analyses revealed larger placebo effects in manual control interventions compared to disabled devices and miscellaneous control interventions. Overall, placebo analgesia accounted for 39% of treatments' short‐term effectiveness. No placebo effects were found at medium‐term (7 RCTs, 381 participants) or long‐term follow‐up (3 RCTs, 173 participants). Conclusions: The observed placebo analgesia has mechanistic and methodological implications, though its clinical importance may be limited. Control intervention design affects placebo effects, highlighting the importance of considering methodology in RCT interpretation. Review limitations include a small number of long‐term studies and sample heterogeneity. Significance: This systematic review directly quantifies placebo effects from physical and psychological 'sham' control interventions and compares them to treatments' overall effectiveness. By doing so, the review enhances our understanding of placebo effects, their relative contribution in clinical trials, and their susceptibly to trial design. It poses further questions regarding the influence of blinding, participant expectations, and features of the therapeutic context. Overall, the insights provided by this review carry methodological significance and are important for the interpretation and synthesis of efficacy trials in this field. [ABSTRACT FROM AUTHOR]

Background: Chronic pain affects approximately 30% of the general population, severely degrades quality of life and professional life, and leads to additional health care costs. Moreover, the medical follow-up of patients with chronic pain remains complex and provides only fragmentary data on painful daily experiences. This situation makes the management of patients with chronic pain less than optimal and may partly explain the lack of effectiveness of current therapies. Real-life monitoring of subjective and objective markers of chronic pain using mobile health (mHealth) programs could better characterize patients, chronic pain, pain medications, and daily impact to help medical management., Objective: This cohort study aimed to assess the ability of our mHealth tool (eDOL) to collect extensive real-life medical data from chronic pain patients after 1 year of use. The data collected in this way would provide new epidemiological and pathophysiological data on chronic pain., Methods: A French national cohort of patients with chronic pain treated at 18 pain clinics has been established and followed up using mHealth tools. This cohort makes it possible to collect the determinants and repercussions of chronic pain and their evolutions in a real-life context, taking into account all environmental events likely to influence chronic pain. The patients were asked to complete several questionnaires, body schemes, and weekly meters, and were able to interact with a chatbot and use educational modules on chronic pain. Physicians could monitor their patients' progress in real time via an online platform., Results: The cohort study included 1427 patients and analyzed 1178 patients. The eDOL tool was able to collect various sociodemographic data; specific data for characterizing pain disorders, including body scheme; data on comorbidities related to chronic pain and its psychological and overall impact on patients' quality of life; data on drug and nondrug therapeutics and their benefit-to-risk ratio; and medical or treatment history. Among the patients completing weekly meters, 49.4% (497/1007) continued to complete them after 3 months of follow-up, and the proportion stabilized at 39.3% (108/275) after 12 months of follow-up. Overall, despite a fairly high attrition rate over the follow-up period, the eDOL tool collected extensive data. This amount of data will increase over time and provide a significant volume of health data of interest for future research involving the epidemiology, care pathways, trajectories, medical management, sociodemographic characteristics, and other aspects of patients with chronic pain., Conclusions: This work demonstrates that the mHealth tool eDOL is able to generate a considerable volume of data concerning the determinants and repercussions of chronic pain and their evolutions in a real-life context. The eDOL tool can incorporate numerous parameters to ensure the detailed characterization of patients with chronic pain for future research and pain management., Trial Registration: ClinicalTrials.gov NCT04880096; https://clinicaltrials.gov/ct2/show/NCT04880096., (©Noémie Delage, Nathalie Cantagrel, Sandrine Soriot-Thomas, Marie Frost, Rodrigue Deleens, Patrick Ginies, Alain Eschalier, Alice Corteval, Alicia Laveyssière, Jules Phalip, Célian Bertin, Bruno Pereira, Chouki Chenaf, Bastien Doreau, Nicolas Authier, ePAIN, Nicolas Kerckhove. Originally published in JMIR mHealth and uHealth (https://mhealth.jmir.org), 12.06.2024.)