Perception and acquaintance of stroke specialists on non-inferiority trials: An international survey.

Introduction: The adoption of non-inferiority trial designs for assessing new interventions in stroke treatment is on the rise. We designed a survey to assess stroke specialists' understanding and familiarity with non-inferiority trials and margins.

Methods: A brief web-based questionnaire was sent to the members of the World Stroke Organization (WSO). The median acceptable non-inferiority margins in different research settings provided by responders were summarized and reported according to the acquaintance of responders with non-inferiority trials.

Results: A total of 120 WSO members from 42 countries responded to the survey. Thirty-two percent (32 %) of respondents self-identified as being very familiar with non-inferiority trials, while 6 % identified as extremely familiar. When asked about the impact of non-inferiority trials on improving stroke patient care, 42 % rated it as high and 45 % as moderate. 83 % of responders reported that the findings of non-inferiority trials affect their clinical practice. Ease of administration, relative effect of the standard treatment, clinical implications of inappropriately introducing the new treatment, availability, price, ease of storage and shipping were all considered as factors that should influence the size of the non-inferiority margin. The magnitude and variability of acceptable non-inferiority margins were seen to decrease as the acquaintance of responders with non-inferiority trials increased.

Conclusion: Although responders acknowledge the importance of non-inferiority trials, most have limited acquaintance with this research design. Educational activities are needed to enhance literacy in non-inferiority trials and the interpretation of non-inferiority margins.