Reliability of a computational model for evaluating thoracoabdominal mobility in newborns: a cross-sectional study

The present study aimed to verify the inter and intra-examiner reliability of an interactive custom-made MATLAB® App for bio-photogrammetric analysis of thoracoabdominal mobility in newborns and compare the respiratory rate (RR) results between the automatic MATLAB® App and its manual counterpart. This is a cross-sectional study conducted in 27 healthy newborns of both sexes (gestational age between 37 and 41 weeks and up to 72 h of life) who did not cry during data acquisition. Chest and abdominal areas of the subjects in the supine position were analyzed through 60 s videos, totaling 30,714 photograms. All photograms were analyzed by three examiners on three different occasions. Analysis of variance (ANOVA) and intraclass correlation coefficient (ICC) were applied, adopting a 95% confidence interval and significance level of α = 0.05. Reliability was excellent for intra (ICC 0.81-0.96) and inter-examiner correlations (ICC 0.84-0.99) between the chest and abdominal areas, in both inspiration and expiration, with no differences between them. Evaluation of newborns' thoracoabdominal mobility using the custom-made MATLAB® App for bio-photogrammetric analysis exhibited good to excellent intra- and inter-examiner reliability and an excellent correlation between manual and automatic models for measuring RR. Thus, it proved to be an objective and practical tool for bedside thoracoabdominal mobility assessment in different clinical situations involving neonatal care.