How can non-inferiority studies with mortality end points be ethically justified?

Area of Science:

• Clinical Trials
• Medical Ethics
• Health Research

Background:

• Non-inferiority (NI) studies with mortality endpoints are increasingly common.
• These studies assess if a new treatment is not unacceptably worse than a comparator regarding mortality.
• Ethical considerations regarding study rationale, NI margins, certainty, and informed consent require attention.

Purpose of the Study:

• To analyze the ethical issues surrounding NI studies with mortality endpoints.
• To provide ethical reflection on the design and conduct of such trials.
• To highlight the need for clearer justifications and patient involvement.

Main Methods:

• Literature search on NI, mortality, and ethics in PubMed, CINAHL, and Embase.
• Analysis of ethical issues informed by existing research.
• Illustration of results using the PROFID-EHRA NI trial example.

Main Results:

• Justifications for NI over superiority designs are often inadequate.
• NI margins are frequently adopted from prior studies without sufficient rationale.
• There is a lack of consensus on patient involvement in study design, justification, and informed consent processes.

Conclusions:

• NI studies with mortality endpoints are ethically justifiable with proven, significant secondary benefits and patient-acceptable NI margins.
• NI margin acceptability should be assessed case-by-case, with risks clearly communicated.
• Explicit justification for NI over superiority designs is needed, alongside further research on patient perspectives and outcome certainty.