Pedro Glusman Knijnik1, Jeruza Lavanholi Neyeloff2, Brasil Silva Neto3. 1. Faculty of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil. Electronic address: knijnik.pedro@gmail.com. 2. Vice Directory, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil. 3. Faculty of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Urology Department, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil.
We read with great interest the meta-analysis by Zhou et al regarding the long-term efficacy and tolerance of tadalafil daily compared with tadalafil on demand, published in Sexual Medicine in June 2019. It was a well-designed and well-conducted study, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.In this article, the authors analyzed 4 randomized controlled trials and concluded that tadalafil daily provides a preferable therapeutic effect for erectile dysfunction with a lower incidence of side effects relative to tadalafil on demand after, at least, 24 weeks of treatment.The conclusion regarding the superiority of daily usage in comparison with tadalafil on demand was drawn by the analysis of the IIEF-EF questionnaire and the response to questions 2 (Sexual Encounter Profile [SEP2]) and 3 (SEP3) of the SEP Diary. In the results section, the authors reported that the tadalafil daily group had a greater increase of IIEF-EF (MD = 1.24; 95% CI = 0.03–2.44; P = 0.04), SEP2 (MD - 10.08; 95% CI = 9.15–11.01; P < 0.00001) and SEP3 (MD - 8.19; 95% CI = 2.09–14.29; P < 0.00001) in comparison tadalafil on demand, which suggest the superiority of tadalafil daily. However, when we analyze the forests plots figures, we observe the opposite results: this greater improvement described in the tadalafil daily group is actually observed in tadalafil on-demand group.We kindly ask the authors to clarify this discrepancy between the results observed in the forest plot figures and what is reported in the body of the article.
Statement of authorship
Conception and DesignBrasil Silva Neto; Pedro Glusman KnijnikAcquisition of DataBrasil Silva Neto; Pedro Glusman Knijnik; Jeruza Lavanholi NeyeloffAnalysis and Interpretation of DataPedro Glusman Knijnik; Jeruza Lavanholi Neyeloff; Brasil Silva NetoDrafting the ArticleBrasil Silva Neto; Pedro Glusman KnijnikRevising It for Intellectual ContentPedro Glusman Knijnik; Jeruza Lavanholi NeyeloffFinal Approval of the Completed ArticleBrasil Silva Neto; Jeruza Lavanholi Neyeloff