What is it about?

This article is a response to another article that compared several PEP (positive expiratory pressure) devices. These are devices that help improve expiration and cough strength, for example. We point out that some of the compared devices may not have been comparable, as their main use is not PEP. In particular, The Breather, is a respiratory muscle training device strengthening the inspiratory and the expiratory muscles, and is substantially different from the other devices. We have used this device in many clinical studies and point out that it was not used according to manufacturer instructions in the article that this letter is responding to. Furthermore, it has a different mechanism from the other devices compared in the original article, which may make a comparison less useful. Based on these flaws, we suggest that the obtained results of functionality should be revised.

Why is it important?

This letter has been published as part of a public communication between researchers who disagree on methodology and result of a study comparing several similar, but not equivalent, medical devices. This is important as it highlights potential flaws that may have gone unnoticed during the peer review process, which should check accuracy of the research approach, but has its limitations as it may not be familiar with the adequate use of every device. Furthermore, publication of full research communications is valuable, as the reader gains insight into two sides of an argument, which furthers education and critical evaluation of scientific articles.