Corrigendum to: Ventilatory inefficiency during graded exercise in COPD: A pragmatic approach (Clinical Physiology and Functional Imaging, (2021), 41, 1, (103-109), 10.1111/cpf.12674)

Abstract

Specific Author Contribuitions Muller, PT: Study design, literature search, data collection, analysis of data, manuscript preparation, and review; Saraiva, EF: Study design, literature search, data collection, analysis of data, manuscript preparation and review. All the authors contributed to the writing and editing of the manuscript. Research Support and grant This study was supported by the Federal University of Mato Grosso do Sul. Original article number of words: 2,719 words Contact author address: P.T.Müller, DSc. Head, Laboratory of Respiratory Pathophysiology (LAFIR); Respiratory Division of University Hospital, Federal University of Mato Grosso do Sul (UFMS). Rua Filinto Müller S/N, Vila Ipiranga, CEP:79080-090, Campo Grande, Brazil. Phone: (+55-67) 33453149. FAX: (+55-67) 33453049. e-mail: paulo.muller@ufms.br [ERRATUM] The authors have recently verified a miscalculation in the data set used for the manuscript entitled “Ventilatory Inefficiency During Graded Exercise in COPD: A Pragmatic Approach” (Clin Physiol Funct Imaging 2021; 41 (1): 103-109). The equations for the prediction of maximal voluntary ventilation (MVV) for the Brazilian population were assessed both from the book “Clinical Exercise Physiology: Theory and Practice” (JA Neder & LE Nery, 1o. Edition, 2003, Editora Artes Médicas LTDA) and from the source article (Neder J A, Andreoni S, Lerario MC, and Nery LE. Reference values for lung function tests. II. Maximal respiratory pressures and voluntary ventilation Braz J Med Biol Res 1999; 32 (6):719-27). Unfortunately, for convenience, the authors decided to perform the calculation based on the book. The book misreproduced the equations from the article (without a “minus sign” in the age factor), leading the authors to make a systematic overestimation of the MVV. This error specifically impacts only the calculation of the new variable for ventilatory efficiency ηV'E. Fortunately, the key results and conclusions of the manuscript were not affected by this error. The authors have now recalculated MVV based on the equations from the article cited in the original paper, resulting in values approximately twice as high for the ηV'E (new Figure 3E and new Table 2). The corrected results from the new analysis slightly alter the position of the ηV'E in the second-best model based on the logistic regression approach. However, both CO2 output constant rate and ηV'E are closely dependent on each other and the conclusions remain unchanged. 3 Figure (Figure presented.) Box-plots and whiskers represent successive comparisons between GOLD stages and controls forV'E-V'CO2 slope (A), V'E-V'CO2 intercept (B), V'E-V'CO2 nadir (C), actual CO2 output constant rate (CO2-ACR, D) and ηVE (E). 2 Table Ventilatory efficiency parameters and values, statistical comparisons between the groups and best model evaluated through Multinomial Logistic Regression. (Table presented.) Note: One-way ANOVA comparing GOLD II, III, and IV with at risk COPD and respective p-value. Abbreviations: AIC, Akaike Information Criterion; BIC, Bayesian Information Criterion; V'E, minute-ventilation; V'CO2, exhaled carbon dioxide; ηV'E, ventilatory efficiency. RESULTS (page 5) The best model to discriminate disease severity was the new approach, including the CO2 output constant rate (AIC = 85 and BIC = 95) followed by the ηV'E' (AIC = 86 and BIC = 96) (Table 2).