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Use of oximetry to screen for paediatric obstructive sleep apnoea: is one night enough and is 6 hours too much?
  1. Niamh Catherine Galway1,
  2. Barbara Maxwell1,
  3. Michael Shields1,2,
  4. Dara O'Donoghue1,3
  1. 1 Paediatric Respiratory Department, Royal Belfast Hospital for Sick Children, Belfast, UK
  2. 2 Queen's University Belfast Centre for Infection and Immunity, Belfast, UK
  3. 3 Centre for Medical Education, Queen's University Belfast, Belfast, UK
  1. Correspondence to Dr Dara O'Donoghue, Paediatric Respiratory Department, Royal Belfast Hospital for Sick Children, Belfast BT12 6BA, UK; d.odonoghue{at}


Introduction Nocturnal pulse oximetry can be used to screen for obstructive sleep apnoea (OSA) using the McGill Oximetry Score (MOS). The MOS has a time threshold for a technically adequate study of 6 hours. It has been suggested that one night of oximetry is sufficient to screen for OSA using the MOS.

Aims (1) To evaluate night-to-night variation of the MOS. (2) To determine the impact of recording three nights of oximetry on the screening yield for OSA. (3) To explore whether useful MOS data are discarded when a threshold of 6 hours of oximetry recording is used.

Methods A retrospective study of nocturnal pulse oximetry done at home over three consecutive nights in paediatric patients with suspected OSA. Studies were scored (MOS) using thresholds of ≥6 and ≥4 hours of recording.

Results A total of 329 patients were studied. MOS scores over three nights showed only fair to moderate agreement. On the first night 126 patients (38%) screened positive for OSA. When three nights of oximetry were done 195 patients (59%) screened positive on at least one of the nights. There were 48 patients with studies of between 4 and 6 hours duration on one or more nights. If these studies are scored 20 patients (42%) would screen positive for OSA on at least one night based on scoring these studies alone.

Conclusion One night of oximetry screening may not be sufficient to screen for OSA. Lowering the time threshold to ≥4 hours may increase the screening capability of nocturnal oximetry.

  • respiratory
  • sleep

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  • Contributors NCG collected the data, analysed the data and cowrote the paper. BM collected the data and cowrote the paper. MS helped with study design, analysed the data and cowrote the paper. DOD conceived the study, supervised the data collection and data analysis and cowrote the paper.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient consent for publication Not required.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement All data relevant to the study are included in the article or uploaded as supplementary information.

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