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SYSTEMATIC REVIEW article

Front. Neurol.

Sec. Sleep Disorders

Volume 16 - 2025 | doi: 10.3389/fneur.2025.1600767

This article is part of the Research TopicThe Promise of Sleep TechnologyView all 5 articles

Industry sponsorship bias in randomized controlled trials of digital cognitive behavioral therapy for insomnia: A meta research study based on the 2023 Brazilian Guidelines on the Diagnosis and Treatment of Insomnia in Adults

Provisionally accepted
Viviane  Akemi KakazuViviane Akemi Kakazu1Marcia  AssisMarcia Assis2Andrea  BacelarAndrea Bacelar3Andréia  Gomes BezerraAndréia Gomes Bezerra1Giovanna  Lira Rosa CiuttiGiovanna Lira Rosa Ciutti1Silvia  Gonçalves ConwaySilvia Gonçalves Conway4,5,6José  Carlos Fernandes GaldurózJosé Carlos Fernandes Galduróz1Luciano  Ferreira DragerLuciano Ferreira Drager7Mariana  Pery KhouryMariana Pery Khoury1,8Ingrid  Porto Araújo LeiteIngrid Porto Araújo Leite1Ygor  de Matos LucianoYgor de Matos Luciano1Dalva  PoyaresDalva Poyares1Sergio  TufikSergio Tufik1,9Gabriel  Natan PiresGabriel Natan Pires1*
  • 1Departamento de Psicobiologia, Universidade Federal de São Paulo, São Paulo, São Paulo, Brazil
  • 2Clínica do Sono de Curitiba, Hospital São Lucas, Curitiba, Paraná, Brazil
  • 3Clínica Bacelar - Neuro e Sono, Rio de Janeiro, Paraná, Brazil
  • 4Instituto de Psiquiatria (IPq), Universidade de São Paulo, São Paulo, Rio Grande do Sul, Brazil
  • 5Departamento de Otoneurologia, Universidade de São Paulo, SAO PAULO, Brazil
  • 6AkasA - Formação e Conhecimento, SAO PAULO, Brazil
  • 7Heart Institute (InCor), São Paulo, Sao Paulo, Brazil
  • 8Universidade Santo Amaro, São Paulo, São Paulo, Brazil
  • 9Instituto do Sono (Brazil), São Paulo, São Paulo, Brazil

The final, formatted version of the article will be published soon.

Background: Industry sponsorship bias refers to the tendency of a study, most likely clinical trials, to produce results that favor the sponsor's interest. It is especially relevant in cases in which a study is funded by companies or organizations with a commercial interest in the product or technology being evaluated. Digital Cognitive Behavioral Therapy for Insomnia (dCBT-I) is a widely used nonpharmacological treatment, and research in this area is often funded by organizations that have a commercial interest in this treatment. This study aimed to assess whether industry sponsorship bias in dCBT-I trials is associated with more favorable outcomes. Methods: This study was based on the sample of randomized controlled trials (RCTs) included at the "2023 Brazilian Guidelines on the Diagnosis and Treatment of Insomnia in Adults". Inclusion criteria included 1. Diagnosis using ICSD-3, DSM-5, Insomnia Severity Index (ISI) or Athens Insomnia Scale (AIS). 2. dCBT-I as intervention. 3. Other forms of CBT-I or negative control groups as comparators, and 4. ISI as main outcome. Immediate post-treatment ISI data was extracted for both intervention and control groups in each included study, and the betweengroups Cohen's d effect size was calculated for each included study. Methodological quality was evaluated using the van Tulder scale. Results: Twenty-eight analyses of RCTs were included. Interventions such as SHUTi (Sleep Healthy Using the Internet) (39.28%) and Online CBT-I (28.57%) were the most common, with comparators such as minimal intervention (50%) and waiting list (32.14%). There was a significant association between the risk of sponsorship bias and open access publication [X²(1)=5.250; p=0.022], as well as between the risk of sponsorship bias and lower levels of methodological quality [X²(1)=4.861; p=0.027]. There was no correlation between risk of bias levels and Insomnia Severity Index (ISI) mean scores (the main indicator of outcomes) in the control and experimental groups. These results suggest that the risk of sponsorship bias may impact the methodological quality of studies and compliance with established standards. Conclusion: A greater risk of sponsorship bias was associated with lower methodological quality articles and open access publication.

Keywords: Sleep, Industry Sponsorship Bias, cognitive behavioral therapy, Systematic review, Meta-research

Received: 26 Mar 2025; Accepted: 07 Jul 2025.

Copyright: © 2025 Kakazu, Assis, Bacelar, Bezerra, Ciutti, Conway, Galduróz, Drager, Khoury, Leite, Luciano, Poyares, Tufik and Pires. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Gabriel Natan Pires, Departamento de Psicobiologia, Universidade Federal de São Paulo, São Paulo, 04023062, São Paulo, Brazil

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.