To develop a measure of sleep fragmentation in children with upper airway obstruction based on survival curve analysis of sleep continuity.
Prospective repeated measures.
Hospital sleep laboratory.
92 children aged 3.0 to 12.9 years undergoing 2 overnight polysomnographic (PSG) sleep studies, 6 months apart. Subjects were divided into 3 groups based on their obstructive apnea and hypopnea index (OAHI) and other upper airway obstruction (UAO) symptoms: primary snorers (PS; n = 24, OAHI < 1), those with obstructive sleep apnea syndrome (OSAS; n = 20, OAHI ≥ 1) and non-snoring controls (C; n = 48, OAHI < 1).
Subjects in the PS and OSAS groups underwent tonsillectomy and adenoidectomy between PSG assessments.
Measurements and Results:
Post hoc measures of movement and contiguous sleep epochs were exported and analyzed using Kaplan-Meier estimates of survival to generate survival curves for the 3 groups. Statistically significant differences were found between these group curves for sleep continuity (P < 0.05) when using movement events as the sleep fragmenting event, but not if stage 1 NREM sleep or awakenings were used.
Using conventional indices of sleep fragmentation in survival curve analysis of sleep continuity does not provide a useful measure of sleep fragmentation in children with upper airway obstruction. However, when sleep continuity is defined as the time between gross body movements, a potentially useful clinical measure is produced.
Coussens S, Baumert M, Kohler M, Martin J, Kennedy D, Lushington K, Saint D, Pamula Y. Movement distribution: a new measure of sleep fragmentation in children with upper airway obstruction. SLEEP 2014;37(12):2025-2034.