Transcutaneous electrical nerve stimulation and interferential current demonstrate similar effects in relieving acute and chronic pain: a systematic review with meta-analysis.

BACKGROUND Transcutaneous electrical nerve stimulation and interferential current have been widely used in clinical practice. However, a systematic review comparing their effects on pain relief has not yet been performed. OBJECTIVES To investigate the effects of transcutaneous electrical nerve stimulation and interferential current on acute and chronic pain. METHODS We use Pubmed, Embase, LILACS, PEDro and Cochrane Central Register of Controlled Trials as data sources. Two independent reviewers that selected studies according to inclusion criteria, extracted information of interest and verified the methodological quality of the studies made study selection. The studies were selected if transcutaneous electrical nerve stimulation and interferential current were used as treatment and they had pain as the main outcome, as evaluated by a visual analog scale. Secondary outcomes were the Western Ontario Macmaster and Rolland Morris Disability questionnaires, which were added after data extraction. RESULTS Eight studies with a pooled sample of 825 patients were included. The methodological quality of the selected studies was moderate, with an average of six on a 0-10 scale (PEDro). In general, both transcutaneous electrical nerve stimulation and interferential current improved pain and functional outcomes without a statistical difference between them. CONCLUSION Transcutaneous electrical nerve stimulation and interferential current have similar effects on pain outcome The low number of studies included in this meta-analysis indicates that new clinical trials are needed.