Study objectives: This report describes clinical outcomes and threshold levels of respiratory disturbance index (RDI) associated with sleep-disordered breathing in children participating in the Tucson Children's Assessment of Sleep Apnea study.
Design: A community-based, prospective cohort study designed to assess the severity of sleep-related symptoms associated with sleep-disordered breathing in children aged 6 to 11 years.
Setting: Students attending elementary school in the Tucson Unified School District.
Participants: Unattended home polysomnograms were completed on 239 children-55.2% boys, 51% Hispanic, and 55% between the ages of 6 and 8 years.
Measurements and results: Based on full home polysomnography, levels of RDI that correspond to a higher prevalence of clinical symptoms of sleep-disordered breathing in children aged 6 to 11 were observed. An RDI of at least 5 was associated with frequent snoring (20.3% vs 9.1%, P<.01), excessive daytime sleepiness (22.9% vs 10.7%, P<.01), and learning problems (8.5% vs 2.5%, P<.04) when no oxygen desaturation accompanied the respiratory event. An RDI of at least 1 was associated with these symptoms when a 3% oxygen desaturation was required, snoring (24.0% vs 10.4%, P<.006), excessive daytime sleepiness (24.0% vs 13.4%, P<.04), and learning problems (10.7% vs 3.0%, P<.02). Hispanic or Caucasian ethnicity, sex, age category, obesity, insomnia, and witnessed apnea were not associated with RDI regardless of event definition.
Conclusions: The Tucson Children's Assessment of Sleep Apnea study has shown that there are values of RDI based on polysomnography that correspond to an increased rate of clinical symptoms in children ages 6 to 11 years.