Efficacy and safety of transcutaneous electrical nerve stimulation (TENS) for acute and chronic pain in adults: a systematic review and meta-analysis of 381 studies (the meta-TENS study)

To investigate the efficacy and safety of transcutaneous electrical nerve stimulation (TENS) for relief of pain in adults.

Systematic review and meta-analysis. DATA SOURCES: Medline, Cochrane Central, Embase (and others) from inception to July 2019 and updated on 17 May 2020. ELIGIBILITY CRITERIA FOR STUDY SELECTION: Randomised controlled trials (RCTs) comparing strong non-painful TENS at or close to the site of pain versus placebo or other treatments in adults with pain, irrespective of diagnosis. DATA EXTRACTION AND SYNTHESIS: 50%) during or immediately after TENS. Random effect models were used to calculate standardised mean differences (SMD) and risk ratios. Subgroup analyses were related to trial methodology and characteristics of pain.