Effectiveness of nonpharmacological interventions on pain reduction among patients undergoing colonoscopy without anesthesia: a systematic review and network meta-analysis of randomized controlled trials.

[BACKGROUND] Pain is the most prominent physical discomfort during colonoscopy without anesthesia and an important factor affecting patients' adherence to screening guidelines of colorectal cancer. However, the optimal nonpharmacological analgesic strategy for colonoscopy without anesthesia remains unclear. This network meta-analysis (NMA) aims to synthesize and rank the effectiveness of existing nonpharmacological interventions for pain reduction to identify the most effective approach.

[METHODS] PubMed, Embase, Web of Science, Scopus, CINAHL Plus, and CENTRAL were systematically searched from their inception to March, 2025. Randomized controlled trials reporting the use of nonpharmacological interventions during colonoscopy without anesthesia were included. Standardized mean differences (SMDs) based on random-effects model was calculated to estimate the effect sizes. The methodological quality of the included studies was appraised using the Revised Cochrane Risk of Bias Tool for Randomized Trials 2.0. NMA was performed within a frequentist framework using the STATA software v17.0.

[RESULTS] A total of 28 RCTs involving 3543 participants were included in this review, encompassing 10 nonpharmacological interventions and 2 control conditions. The result of NMA indicated that, virtual reality (VR), audiovisual distraction, visual distraction, abdominal corset, transcutaneous electrical nerve stimulation, and music listening significantly reduced pain during colonoscopy without anesthesia compared with passive control (SMDs: -0.85 to -0.50) and corresponding placebo (SMDs: -0.99 to -0.65). The results of SUCRA suggested that VR may be the most effective nonpharmacological intervention (86.3%), followed by audiovisual distraction (81.5%), abdominal corset (72.3%), and visual distraction (68.7%). In contrast, the stress ball demonstrated the least effectiveness (16.4%).

[CONCLUSIONS] Attention distraction techniques may represent the most effective nonpharmacological strategies for pain reduction. However, the limited number of studies for some interventions may introduce potential risks of bias in the present analysis. Further research is needed to supplement the findings of our study to provide reliable evidence-based evidence for non-pharmacological analgesia during colonoscopy without anesthesia.