Evaluation of automated pediatric sleep stage classification using U-Sleep - a convolutional neural network

Abstract

Study Objectives U-Sleep is a publicly-available automated sleep stager, but has not been independently validated using pediatric data. We aimed to a) test the hypothesis that U-Sleep performance is equivalent to trained humans, using a concordance dataset of 50 pediatric polysomnogram excerpts scored by multiple trained scorers, and b) identify clinical and demographic characteristics that impact U-Sleep accuracy, using a clinical dataset of 3114 polysomnograms from a tertiary center. Methods Agreement between U-Sleep and gold 30-second epoch sleep staging was determined across both datasets. Utilizing the concordance dataset, the hypothesis of equivalence between human scorers and U-Sleep was tested using a Wilcoxon two one-sided test (TOST). Multivariable regression and generalized additive modelling were used on the clinical dataset to estimate the effects of age, comorbidities and polysomnographic findings on U-Sleep performance. Results The median (interquartile range) Cohens kappa agreement of U-Sleep and individual trained humans relative to gold scoring for 5-stage sleep staging in the concordance dataset were similar, kappa=0.79(0.19) vs 0.78(0.13) respectively, and satisfied statistical equivalence (TOST p<0.01). Median (interquartile range) kappa agreement between U-Sleep 2.0 and clinical sleep-staging was kappa=0.69(0.22). Modelling indicated lower performance for children <2 years, those with medical comorbidities possibly altering sleep electroencephalography (kappa reduction=0.07-0.15) and those with decreased sleep efficiency or sleep-disordered breathing (kappa reduction=0.1). Conclusion While U-Sleep algorithms showed statistically equivalent performance to trained scorers, accuracy was lower in children <2 years and those with sleep-disordered breathing or comorbidities affecting electroencephalography. U-Sleep is suitable for pediatric clinical utilization provided automated staging is followed by expert clinician review.