A New Transient Sham TENS Device Allows for Investigator Blinding While Delivering a True Placebo Treatment

Abstract

This study compared a new transient sham TENS that delivers current for 45 seconds to an inactive sham and active TENS to determine the degree of blinding and influence on pain reduction. Pressure pain thresholds (PPT), heat pain thresholds (HPT), and pain intensities to tonic heat and pressure were measured in 69 healthy adults before and after randomization. Allocation investigators and subjects were asked to identify the treatment administered. The transient sham blinded investigators 100% of the time and 40% of subjects compared to the inactive sham that blinded investigators 0% of the time and 21% of subjects. Investigators and subjects were only blinded 7% and 13% of the time, respectively, with active TENS. Neither placebo treatment resulted in significant changes in PPT, HPT, or pain intensities. Subjects using higher active TENS amplitudes (≥17mAs) had significantly higher PPTs and lower pain intensities to tonic pressure than subjects using lower amplitudes (<17mAs). HPTs and pain intensities to tonic heat were not significantly changed. The transient TENS completely blinds investigators to treatment and does not reduce pain, thereby providing a true placebo treatment.

Dose-specific Effects of Transcutaneous Electrical Nerve Stimulation (TENS) on Experimental Pain

“…36 Other researchers have advocated the use of "barely perceptible" TENS as a placebo. 123 The validity of the placebo used in RCTs in this review depends on the stance taken as to what constitutes a placebo condition. It is recommended that future TENS trials report the success of blinding (whether participants believe they received placebo or active TENS) to be able to judge the credibility of the methods used.…”

Ação da estimulação elétrica nervosa transcutânea sobre o limiar de dor induzido por pressão

“…Isso corrobora os dados de estudo no qual não foram observadas diferenças significativas sobre os efeitos do uso da TENS quando comparada a TENS placebo transitória com a TENS placebo inativa. Em contrapartida; os indivíduos que foram submetidos a TENS ativa apresentaram aumento no limiar de dor por pressão, em comparação com os indivíduos submetidos a TENS transitória e a TENS placebo, com uma maior redução da dor induzida com TENS ativa na maior amplitude de pulso, quando comparado com o de menor amplitude 5 . Outro estudo comparou os efeitos da TENS, em frequência constante (80 Hz) e frequência modulada (20 Hz/100 Hz), com o placebo em quatro momentos.…”

“…A TENS tem sido cada vez mais utilizada devido a sua fácil aplicação e por propiciar menor necessidade de administração de fármacos, promovendo assim o bem estar do paciente e redução de custos com o tratamento. A TENS é um recurso terapêutico amplamente utilizado pelos fisioterapeutas para o tratamento de diversas doenças que produzem dor 5 . Apesar da ampla utilização desse aparelho, com o objetivo de promover analgesia, os estudos apresentam resultados conflitantes com respeito à variação em seus parâme-tros e população estudada, bem como pela forma de ação.…”

Transcutaneous electrical acupoint stimulation as an adjunct therapy for obsessive-compulsive disorder: A randomized controlled study

“…This transient placebo-TENS has been well validated and found to better maintain blinding compared to standard placebo-TENS methods, in which no current was actually delivered to the electrodes (Rakel et al, 2010).…”