title: Respiratory rate and pulse oximetry derived information as predictors of hospital admission in young children in Bangladesh: a prospective observational study.
abstract: Hypoxaemia is a strong predictor of mortality in children. Early detection of deteriorating condition is vital to timely intervention. We hypothesise that measures of pulse oximetry dynamics may identify children requiring hospitalisation. Our aim was to develop a predictive tool using only objective data derived from pulse oximetry and observed respiratory rate to identify children at increased risk of hospital admission.
  
  
  
  Tertiary-level hospital emergency department in Bangladesh.
  
  
  
  Children under 5 years (n=3374) presenting at the facility (October 2012-April 2013) without documented chronic diseases were recruited. 1-minute segments of pulse oximetry (photoplethysmogram (PPG), blood oxygen saturation (SpO2) and heart rate (HR)) and respiratory rate were collected with a mobile app.
  
  
  
  The need for hospitalisation based on expert physician review and follow-up.
  
  
  
  Pulse rate variability (PRV) using pulse peak intervals of the PPG signal and features extracted from the SpO2 signal, all derived from pulse oximetry recordings, were studied. A univariate age-adjusted logistic regression was applied to evaluate differences between admitted and non-admitted children. A multivariate logistic regression model was developed using a stepwise selection of predictors and was internally validated using bootstrapping.
  
  
  
  Children admitted to hospital showed significantly (p<0.01) decreased PRV and higher SpO2 variability compared to non-admitted children. The strongest predictors of hospitalisation were reduced PRV-power in the low frequency band (OR associated with a 0.01 unit increase, 0.93; 95% CI 0.89 to 0.98), greater time spent below an SpO2 of 98% and 94% (OR associated with 10 s increase, 1.4; 95% CI 1.3 to 1.4 and 1.5; 95% CI 1.4 to 1.6, respectively), high respiratory rate, high HR, low SpO2, young age and male sex. These variables provided a bootstrap-corrected AUC of the receiver operating characteristic of 0.76.
  
  
  
  Objective measurements, easily obtained using a mobile device in low-resource settings, can predict the need for hospitalisation. External validation will be required before clinical adoption.
authors.affiliation: Department of Electrical & Computer Engineering, The University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Ainara
authors.initials: A
authors.lastname: Garde
authors.affiliation: Department of Statistics, The University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Guohai
authors.initials: G
authors.lastname: Zhou
authors.affiliation: Centre for Child and Adolescent Health, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh.
authors.forename: Shahreen
authors.initials: S
authors.lastname: Raihana
authors.affiliation: Department of Anesthesiology, Pharmacology & Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Dustin
authors.initials: D
authors.lastname: Dunsmuir
authors.affiliation: Department of Health Sciences and Technology, ETH Zurich, Zürich, Switzerland.
authors.forename: Walter
authors.initials: W
authors.lastname: Karlen
authors.affiliation: Department of Electrical & Computer Engineering, The University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Parastoo
authors.initials: P
authors.lastname: Dekhordi
authors.affiliation: Centre for Child and Adolescent Health, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh School of Public Health, Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Tanvir
authors.initials: T
authors.lastname: Huda
authors.affiliation: Centre for Child and Adolescent Health, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh.
authors.forename: Shams El
authors.initials: SE
authors.lastname: Arifeen
authors.affiliation: Department of Pediatrics, British Columbia Children's Hospital and The University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Charles
authors.initials: C
authors.lastname: Larson
authors.affiliation: Department of Pediatrics, British Columbia Children's Hospital and The University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Niranjan
authors.initials: N
authors.lastname: Kissoon
authors.affiliation: Department of Electrical & Computer Engineering, The University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Guy A
authors.initials: GA
authors.lastname: Dumont
authors.affiliation: Department of Anesthesiology, Pharmacology & Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: J Mark
authors.initials: JM
authors.lastname: Ansermino
mesh_terms: D001145:Arrhythmias, Cardiac / Q000175:diagnosis; D001459:Bangladesh; D002675:Child, Preschool; D002908:Chronic Disease; D042241:Early Diagnosis; D005260:Female; D006760:Hospitalization; D006801:Humans; D000860:Hypoxia / Q000175:diagnosis; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D063731:Mobile Applications; D010092:Oximetry; D010100:Oxygen / Q000097:blood; D017156:Photoplethysmography; D019095:Point-of-Care Systems; D011446:Prospective Studies; D015203:Reproducibility of Results; D056152:Respiratory Rate / Q000502:physiology*
chemical_list: D010100:Oxygen
keywords: Global health; Heart rate variability; Mobile health; Paediatric infectious disease; Pulse oximetry