Publication bias in clinical trials on cannabinoids: a Meta-epidemiologic study

• Grant number: 19/20691-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2019
• End date: October 31, 2020
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Rachel Riera
• Grantee: Gabriel Cambraia Pereira
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

Cannabinoids have been widely used for therapeutic purposes in the most varied clinical conditions. However, evidences on the effectiveness of its use remain scarce, pointing to the necessity of robust and well-designed studies on the subject. Clinical trials represent the main type of primary study to analyze the effect of a therapeutic intervention in a particular health problem, but it is known that much of the conducted clinical trials are not published, featuring one of the major problems of the scientific community: publication bias. The present article will select, in the Clinical trials registry base, randomized or not randomized phase III or IV clinical trials with terminated, completed or unknown status, whose intervention is the use of any cannabinoid for therapeutic purpose. After the selection, we will assess the proportion of included studies that did not have their results reported in articles or in the registry base, the presence of selective reporting of outcomes, the time interval between the article conclusion and the publication of their results in electronic scientific bases and the proportion of studies with multiple publications. In this way, we hope that it will be possible to identify the existence of biases associated with the topic and to demonstrate the importance of publication in the construction of reliable information about the effectiveness of the use of cannabinoids for different clinical conditions.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

PEREIRA, GABRIEL CAMBRAIA; PRATES, GABRIELA; MEDINA, MATHEUS; FERREIRA, CAROLINA; CRUZ LATORRACA, CAROLINA DE OLIVEIRA; PACHECO, RAFAEL LEITE; CABRERA MARTIMBIANCO, ANA LUIZA; RIERA, RACHEL. High frequency of spin bias in controlled trials of cannabis derivatives and their synthetic analogues: A meta-epidemiologic study. JOURNAL OF CLINICAL EPIDEMIOLOGY, v. 140, p. 3-12, DEC 2021. (19/20691-4)