Effects of Transcutaneous Electrical Nerve Stimulation (TENS) on Chronic Pain in Older Adults: a Systematic Review and Meta-Analysis

Purpose of ReviewThis study is aimed to systematically review the effectiveness of transcutaneous electrical nerve stimulation (TENS) in the management of chronic musculoskeletal pain in older adults.Recent FindingsWhile there is no certain method of pain management for older adults, recent developments in electrical stimulation have received attention. The effectiveness of TENS on pain management, quality of life, and concurrent therapy including pharmaceuticals among the older population has generated controversy in the current literature.Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines 2020, PubMed, Web of Science, Embase, and Scopus databases were searched comprehensively from inception to March 2022. Randomized controlled trials regarding the application of TENS in managing chronic, musculoskeletal pain (> 3 months) among adults aged older than 50 years were included. Two independent reviewers extracted the main data from eligible studies. The methodological quality of the studies was evaluated using the Cochrane Handbook for Systematic Reviews of Interventions v5.1.0. Meta-analysis was performed using Review Manager (RevMan) software v5.4. From a total of 2049 citations, 11 randomized controlled trials (RCTs) were eligible for entering this study. Meta-analysis showed that TENS led to a significant improvement in Visual Analogue Score (VAS) (SMD = 1.54, 95% CI = [1.10 to 1.98], p < 0.00001). In addition, disability score was decreased measured by the Roland-Morris Disability (RMD) score (SMD = 1.11, 95% CI = [0.48 to 1.74], p = 0.0005) and Numeric Rating Scale (NRS) (SMD = 1.34, 95% CI = [0.74 to 1.94], p < 0.0001). This systematic review and meta-analysis provides level III evidence that TENS can have a promising effect on improving chronic pain in older individuals. However, due to the heterogeneity among the included studies, these results should be generalized cautiously.