Dear Sirs
In their paper in the June issue of this journal, Aydemir et al.Reference Aydemir, Tezer, Borman, Bodur and Unal1 assert that, in their series, the application of transcutaneous electrical nerve stimulation improved the quality of life of patients with tinnitus. The study did not, however, control for the substantial placebo effect of this treatment.
This placebo effect has been well demonstrated in other studies in which the reduction of pain has been assessed,Reference Conn, Marshall, Yadav, Daly and Jaffer2 including a meta-analysis of low back painReference Brosseau, Milne, Robinson, Marchand, Shea and Wells3 in which no greater effect of real transcutaneous electrical nerve stimulation compared with sham transcutaneous electrical nerve stimulation could be shown. It is also important to note that, in studies of the use of transcutaneous electrical nerve stimulation in tinnitus which used sham transcutaneous electrical nerve stimulation as a placebo, no significant difference was demonstrated between the active and placebo treatments.Reference Dobie, Hoberg and Rees4, Reference Thedinger, Karlsen and Schack5
Owing to the fact that this treatment has a considerable placebo effect, we suggest caution when ascribing the effects seen after application of transcutaneous electrical nerve stimulation to the treatment itself and not to the placebo effect that it generates.
D D Pothier,
C-L Bredenkamp*,
From the Royal United Hospital, Bath, and *SignalTrust UK, London, UK.
Author's reply
Dear Sirs
Pothier and Bredenkamp criticise our study for the lack of placebo control. However, our specific aim was to show that transcutaneous electrical nerve stimulation improves the quality of life of patients with tinnitus, rather than to evaluate its efficacy, which has been well demonstrated previously.Reference Steenerson and Cronin1–Reference Engelberg and Bauer4 Although a placebo effect of transcutaneous electrical nerve stimulation cannot be entirely ruled out, our study provides evidence that suppression of this troubling symptom by such treatment is accompanied by improvement in the quality of the patient's life.
M S Tezer,
Department of Otorhinolaryngology, Ankara Numune Education and Research Hospital, Ankara, Turkey.
