Effectiveness and safety of Fu’s subcutaneous needling for pain: A systematic review and Meta-analysis with trial sequential analysis☆

Objective To evaluate the effectiveness and safety of Fu’s subcutaneous needling (FSN) for various pain subtypes and assess the reliability of available evidence using trial sequential analysis (TSA). Methods Seven electronic databases (PubMed, Web of Science, Embase, Cochrane Library, China National Knowledge Infrastructure, Wanfang Database, and Chongqing VIP Database) were searched for randomized controlled trials (RCTs) of FSN for pain management. Eligible studies were screened, and methodological quality assessed using the RoB 1 tool. A meta-analysis was conducted using RevMan and Stata to synthesize pain relief and adverse event data. The required information size (RIS) was calculated using TSA. Results Forty-five RCTs involving 3,180 participants were included. Pooled analysis showed that FSN had superior analgesic effect compared with acupuncture (standardized mean difference (SMD) = −1.29, 95% confidence interval (CI: −1.59 to −0.99), electroacupuncture (SMD = −1.34, 95% CI: −1.80 to −0.87), transcutaneous electrical nerve stimulation (SMD = −1.02, 95% CI: −1.36 to −0.68), and non-steroidal anti-inflammatory drugs (SMD = −1.40, 95% CI: −1.98 to −0.82). Subgroup analyses demonstrated consistent analgesic effects across musculoskeletal pain (SMD = −1.23, 95% CI: −1.47 to −0.99), neuropathic pain (SMD = −1.56, 95% CI: −2.09 to −1.03), acute pain (SMD = −1.21, 95% CI: −1.60 to −0.83), and chronic pain (SMD = −1.25, 95% CI: −1.51 to −0.98) in the visual analog scale scores. TSA revealed that the cumulative sample size exceeded the RIS, indicating robust evidence to support FSN’s analgesic effect. Additionally, adverse event analysis showed that the FSN group (20 events among 663 patients, 3.01%) had a lower incidence of adverse events than the control group (36 events among 663 patients, 5.43%), with a pooled risk ratio of 0.59 (95% CI: 0.35 to 0.97, P = 0.04). Conclusions FSN is a safe and effective nonpharmacological intervention for pain, usable alone or with pharmacotherapy. Limitations include moderate study quality and geographic concentration. High-quality multicenter RCTs are needed to confirm its efficacy and generalizability.