Comparing standard and non-standard videolaryngoscopes in children: methodological issues

Editor—We read with great interest the recent article by Peyton and colleagues1Peyton J. Park R. Staffa S.J. et al.PeDI Collaborative InvestigatorsA comparison of videolaryngoscopy using standard blades or non-standard in children Paediatric Difficult Intubation Registry.Br J Anaesth. 2021; 126: 331-339Abstract Full Text PDF PubMed Scopus (17) Google Scholar comparing performance videolaryngoscopes for tracheal intubation children. They showed that infants weighing <5 kg, a videolaryngoscope increased success rate compared videolaryngoscopes. Since management difficult paediatric airways is challenge to anaesthetists benefits are often significant,2Xue F.S. Liu Y.Y. Li H.X. Yang G.Z. video laryngoscopy airway management: what's clinical evidence?.Anaesth Crit Care Pain Med. 2018; 37: 459-466Abstract (6) Scholar,3Fiadjoe J.E. Nishisaki A. Jagannathan N. al.Airway complications from Pediatric (PeDI) registry: prospective cohort analysis.Lancet Respir 2016; 4: 37-48Abstract (201) their findings have potential implications. Other than limitations described authors discussion, this retrospective analysis Registry data has several methodological issues. First, entry criterion 2 patients was direct physically impossible, including limited mouth opening inability intubate trachea because anatomical abnormality. In fact, these factors can also cause patients.4Tsao M. Vargas A.A. Hajduk Singh devices: an update on advances future directions.Expert Rev Med Devices. 15: 911-927Crossref (3) Based provided methods, we do not believe devices could effectively be used whom impossible This selection bias may confounded interpretation findings. Second, based body weight, were stratified into four subgroups perform further comparisons However, number included each subgroup provided. use rates >5 kg more small differences between kg. Given lack sample size information, cannot exclude possibility study underpowered show three Third, multivariable performed generalised estimating equations determine independent associations device types successful it unclear why all baseline variables selected as covariates entered models. According general principles models, only statistical significance initial incorporated univariable model examine multicollinearity among candidate covariate variables. Furthermore, P<0.2 univariate adjustment. By such adjustment patient characteristics controlling biases, independently associated identified.5Vittinghoff E. McCulloch C.E. Relaxing rule ten events per variable logistic Cox regression.Am Epidemiol. 2007; 165: 710-718Crossref (2137) Because question, concerned inference would been distorted. Fourth, directly technical difficulties entire unnecessary value, there significant interventions effects confounding avoided. When association attempts occurrence complications, very interested knowing which Finally, results Hosmer-Lemeshow goodness-of-fit test c-index Thus, whether models established had good fit adequate discriminative performance.6Hosmer D.W. Lemeshow S. Applied regression.2nd Edn. Wiley, New York2000Crossref We addressing above issues improve transparency help The declare they no conflicts interest. None received financial support work.