[Non-inferiority and equivalence trials: Key methodological issues]

Non-inferiority and equivalence trials aim to promote new treatments that are not expected to be superior to existing ones in a given indication. In order to compensate for a possible loss of efficacy, the new treatment should offer other advantages compared to the reference treatment, a better safety of use for example. Their methods somewhat differ from those of superiority trials, often better known to the medical community. This article presents the key points of the methodology of non-inferiority and equivalence trials in order to inform the readers of such trials about the issues and critical points. The general methodology (hypotheses, decision rules, number of subjects required, and strategy of analysis) is presented using examples and graphic illustrations. The issues and critical points are identified and discussed, in particular the choice of the comparator and of the margin of non-inferiority.

[The choice of inhalation device: A medical act]

Inhaled treatments are essential for respiratory diseases management, including COPD and asthma. Optimal control of the disease largely depends on patient's compliance and proper use of these treatments. Different types of ready-to-use inhaler devices are available: metered dose inhaler, dry powder inhaler or soft mist inhaler. Each of these devices presents specific characteristics and constraints that have to be evaluated and taken into account before prescription. In order to optimize adherence and treatment efficacy, the choice of inhaler device should depend on the specific needs, abilities and preferences of each patient and a specific education to treatment should be provided. Inhaled treatments, even containing the same drug, have different technical constraints and are thus not easily interchangeable. Their substitution without prior medical consent and without proper training can lead to errors in taking treatment, treatment failures and increased health care consumption. In France, substitution by the pharmacist is not authorized. While patient education must be carried out in collaboration with all health professionals, it is preferable that the choice of inhaler device remains the responsibility of the physician.