To the Editor:
Because of irregularities in the randomization procedures, we wish to retract the following article: Primary Prevention of Cardiovascular Disease with a Mediterranean Diet. N Engl J Med 2013;368:1279-90. DOI: 10.1056/NEJMoa1200303.1 We have reanalyzed the data and have published a new report: Primary Prevention of Cardiovascular Disease with a Mediterranean Diet Supplemented with Extra-Virgin Olive Oil or Nuts. N Engl J Med. DOI: 10.1056/NEJMoa1800389.2
Ramón Estruch, M.D., Ph.D.
CIBEROBN, Madrid, Spain
Emilio Ros, M.D., Ph.D.
Instituto de Investigaciones Biomédicas Augusto Pi Sunyer, Barcelona, Spain
Jordi Salas-Salvadó, M.D., Ph.D.
Rovira i Virgili University, Tarragona, Spain
Maria-Isabel Covas, D.Pharm., Ph.D.
Hospital del Mar Medical Research Institute, Barcelona, Spain
Dolores Corella, D.Pharm., Ph.D.
University of Valencia, Valencia, Spain
Fernando Arós, M.D., Ph.D.
University Hospital Araba, Vitoria, Spain
Enrique Gómez-Gracia, M.D., Ph.D.
University of Malaga, Malaga, Spain
Valentina Ruiz-Gutiérrez, Ph.D.
Instituto de la Grasa, Seville, Spain
Miquel Fiol, M.D., Ph.D.
Institute of Health Sciences, Palma de Mallorca, Spain
José Lapetra, M.D., Ph.D.
Distrito Sanitario Atención Primaria, Seville, Spain
Rosa M. Lamuela-Raventos, D.Pharm., Ph.D.
University of Barcelona, Barcelona, Spain
Lluís Serra-Majem, M.D., Ph.D.
Research Institute of Biomedical and Health Sciences, Las Palmas, Spain
Xavier Pintó, M.D., Ph.D.
Bellvitge University Hospital, Barcelona, Spain
Josep Basora, M.D., Ph.D.
Miguel A. Muñoz, M.D., Ph.D.
Instituto de Investigación en Atención Primaria J. Gol, Barcelona, Spain
José V. Sorlí, M.D., Ph.D.
University of Valencia, Valencia, Spain
J. Alfredo Martínez, D.Pharm., M.D., Ph.D.
Miguel A. Martínez-González, M.D., Ph.D.
University of Navarra, Pamplona, Spain
This letter was published on June 13, 2018, at NEJM.org.
Editor’s note: An analysis of reports of randomized trials for improbable distributions of baseline data included 934 reports published in the Journal and identified 11 with distributions of baseline variables that did not appear consistent with randomization (Carlisle JB. Anaesthesia 2017;72:944-52. DOI: 10.1111/anae.13938. Epub 2017 June 4). We reviewed these 11 trial reports and replicated the Carlisle analysis. In 5 reports, standard errors were inadvertently reported as standard deviations, or vice versa. These errors explained the findings and have been corrected; the 5 reports are as follows: High-Dose Atorvastatin after Stroke or Transient Ischemic Attack (N Engl J Med 2006;355:549-59), Treatment of Periodontitis and Endothelial Function (N Engl J Med 2007;356:911-20), Extended Antiretroviral Prophylaxis to Reduce Breast-Milk HIV-1 Transmission (N Engl J Med 2008;359:119-29), Effect of Bronchoconstriction on Airway Remodeling in Asthma (N Engl J Med 2011;364:2006-15), and Horse versus Rabbit Antithymocyte Globulin in Acquired Aplastic Anemia (N Engl J Med 2011;365:430-8). For 5 other reports, limitations in the Carlisle analysis, such as lack of accounting for correlation among baseline variables, most likely explained the findings.
For the remaining report, Primary Prevention of Cardiovascular Disease with a Mediterranean Diet (N Engl J Med 2013;368:1279-90), the authors’ subsequent review of their data and randomization procedures identified protocol deviations, including the enrollment of participants who were not randomized. The authors have therefore withdrawn their original report (Retraction and Republication: Primary Prevention of Cardiovascular Disease with a Mediterranean Diet. N Engl J Med 2013;368:1279-90. N Engl J Med. DOI: 10.1056/NEJMc1806491). The Journal has now published their new report of the study, which describes the protocol deviations and reports reanalyses of the data (Primary Prevention of Cardiovascular Disease with a Mediterranean Diet Supplemented with Extra-Virgin Olive Oil or Nuts. N Engl J Med. DOI: 10.1056/NEJMoa1800389).
1. Estruch R, Ros E, Salas-Salvadó J, et al. Primary prevention of cardiovascular disease with a Mediterranean diet. N Engl J Med 2013;368:1279-1290.
2. Estruch R, Ros E, Salas-Salvadó J, et al. Primary prevention of cardiovascular disease with a Mediterranean diet supplemented with extra-virgin olive oil or nuts. N Engl J Med 2018;378:e34(1)-e34(14).