Journal Information
Vol. 95. Issue 3.
Pages 374-375 (May - June 2019)
Vol. 95. Issue 3.
Pages 374-375 (May - June 2019)
Letter to the Editor
Open Access
Some flaws that could change the effect sizes and limit the extrapolation of these results
Alguns pontos fracos que podem alterar os tamanhos dos efeitos e limitar a extrapolação desses resultados
Visits
1809
Carlos Alberto Velasco-Benítez
Corresponding author
, Herney Andrés García-Perdomo
Universidad del Valle, Cali, Colombia
Related content
This item has received

Under a Creative Commons license
Article information
Full Text
Bibliography
Download PDF
Statistics
Full Text
Dear Editor,

We have carefully read the article published by de Mello et al.,1 and we have found several important issues to discuss.

Regarding the clinical topic, inclusion of studies was based on Rome III Criteria; however, we found that authors misclassified four out of the nine articles included in this systematic review: Castillejo et al.,2 actually used functional constipation (FC) criteria according to Rome II; Mozaffarpur et al.,3 included patients classified using both Rome III criteria and the Paris Consensus on Childhood Constipation Terminology Criteria; Loening-Baucke4 defined FC according to the Medical Position Statement of the North American Society for Pediatric Gastroenterology and Nutrition in 1999; finally, Kokke et al.,5 included patients according to Loening-Baucke.4 This unappropriated inclusion of studies might have led to different effect sizes due to clinical heterogeneity. The authors should have stated that they were going to include different Rome Criteria and afterwards, they should have conducted a sensibility or a subgroup analysis to identify the alteration in effect sizes.

Regarding the methods used to perform this systematic review, we have found some flaws in the following issues6:

  • 1.

    Protocols for systematic reviews and meta-analysis must be published in PROSPERO before performing the entire process and the publication of the final manuscript.

  • 2.

    The search strategy must be based on patient (population), intervention, and study design according to different manuscripts. This one was based on patient, outcome, and study design, which might lead to selection bias.

  • 3.

    Using two tools for assessing bias is unnecessary (RoB Cochrane tool and Jadad score). If the authors wanted to perform another analysis, assessing the quality of evidence using the GRADE tool would have been important and interesting.

  • 4.

    There was no appropriate description of the strategy to identify non-published literature, for example, Google Scholar, Open Grey database, clinical trials registries, and conferences, among others. This might have created publication bias.

Consequently, we suggest caution in the use of the findings when extrapolating results to clinical practice.

Conflicts of interest

The authors declare no conflicts of interest.

References
[1]
P. Piccoli de Mello, D.A. Eifer, E. Daniel de Mello.
Use of fibers in childhood constipation treatment: systematic review with meta-analysis.
J Pediatr (Rio J), 94 (2018), pp. 460-470
[2]
G. Castillejo, M. Bullo, A. Anguera, J. Escribano, F.J. Salas-Salvado.
A controlled, randomized, double-blind trial to evaluate the effect of a supplement of cocoa husk that is rich in dietary fiber on colonic transit in constipated pediatric patients.
Pediatrics, 118 (2006), pp. e641-e648
[3]
S. Mozaffarpur, M. Naseri, M. Esmaeilidooki, M. Kamalinejad, F.A. Bijani.
The effect of cassia fistula emulsion on pediatric functional constipation in comparison with mineral oil: a randomized, clinical trial.
DARU J Pharm Sci, 20 (2012), pp. 83
[4]
V. Loening-Baucke, E. Miele, F.A. Staiano.
Fiber (glucomannan) is beneficial in the treatment of childhood constipation.
Pediatrics, 113 (2004), pp. e259-e264
[5]
F. Kokke, P. Scholtens, M. Alles, T. Decates, T. Fiselier, F.J. Tolboom.
A dietary fiber mixture versus lactulose in the treatment of childhood constipation: a double-blind randomized controlled trial.
JPGN, 47 (2008), pp. 592-597
[6]
J. Higgins, F.S. Green.
Cochrane handbook for systematic reviews of interventions version 5.1.0.
The Cochrane Collaboration, (2011),

Please cite this article as: Velasco-Benítez CA, García-Perdomo HA. Some flaws that could change the effect sizes and limit the extrapolation of these results. J Pediatr (Rio J). 2019;95:374–5.

Copyright © 2019. Sociedade Brasileira de Pediatria
Idiomas
Jornal de Pediatria (English Edition)
Article options
Tools
en pt
Taxa de publicaçao Publication fee
Os artigos submetidos a partir de 1º de setembro de 2018, que forem aceitos para publicação no Jornal de Pediatria, estarão sujeitos a uma taxa para que tenham sua publicação garantida. O artigo aceito somente será publicado após a comprovação do pagamento da taxa de publicação. Ao submeterem o manuscrito a este jornal, os autores concordam com esses termos. A submissão dos manuscritos continua gratuita. Para mais informações, contate assessoria@jped.com.br. Articles submitted as of September 1, 2018, which are accepted for publication in the Jornal de Pediatria, will be subject to a fee to have their publication guaranteed. The accepted article will only be published after proof of the publication fee payment. By submitting the manuscript to this journal, the authors agree to these terms. Manuscript submission remains free of charge. For more information, contact assessoria@jped.com.br.
Cookies policy Política de cookies
To improve our services and products, we use "cookies" (own or third parties authorized) to show advertising related to client preferences through the analyses of navigation customer behavior. Continuing navigation will be considered as acceptance of this use. You can change the settings or obtain more information by clicking here. Utilizamos cookies próprios e de terceiros para melhorar nossos serviços e mostrar publicidade relacionada às suas preferências, analisando seus hábitos de navegação. Se continuar a navegar, consideramos que aceita o seu uso. Você pode alterar a configuração ou obter mais informações aqui.