Study Title
How fragile are Mediterranean diet interventions? A research-on-research study of randomised controlled trials.
Principal Investigator
Maria G. Grammatikopoulou, Meletios P. Nigdelis, Xenophon Theodoridis, et al.
Affiliation
International Hellenic University, Aristotle University of Thessaloniki.
Start Date
September 2020.
End Date
February 2021.
Study Objective
To assess the robustness of randomised controlled trials (RCTs) with Mediterranean diet (MD) interventions using fragility and reverse fragility indices (FI and RFI).
Short Abstract
This study investigated the robustness of RCTs focused on Mediterranean diet interventions. By calculating fragility indices, it was found that many trials lacked robustness, with small event changes capable of altering statistical significance. The findings raised concerns about the strength of evidence underlying MD recommendations, highlighting the need for more rigorous designs in future trials.
Study Design
Systematic review of RCTs with Mediterranean diet interventions, focusing on fragility and reverse fragility indices.
Population
RCTs of various populations, ages, and health conditions.
Sample Size
27 RCTs.
Inclusion Criteria
RCTs on humans of any age or health status, applying Mediterranean diet interventions with dichotomous primary outcomes.
Exclusion Criteria
Trials lacking randomisation or dichotomous primary outcomes, performed on animals, or without event counts.
Intervention/Exposure
Mediterranean diet interventions compared to non-Mediterranean diets or no intervention.
Outcome Measures
Fragility and reverse fragility indices, robustness of results.
Funding Source
Not specified.
Collaborating Institutions
Aristotle University of Thessaloniki, International Hellenic University.
Ethics Approval
Not applicable (systematic review).
Publication Status
Published in BMJ Nutrition, Prevention & Health, March 2021.
Keywords
Mediterranean diet, randomised controlled trials, fragility index, robustness, nutrition recommendations.
Data Collection Methods
Systematic search on PubMed, extraction of event data from trials to calculate FI and RFI.
Primary Data Availability
Data available on request.
Contact Information
Dr. Maria G. Grammatikopoulou,