Sleep-Disordered Breathing in a Population-Based Cohort: Behavioural Outcomes at Four and Seven Years
OBJECTIVES: Examine statistical effects of Sleep-Disordered Breathing (SDB) symptom trajectories from six months to seven years on subsequent behaviour.
METHODS: Parents in the 'Avon Longitudinal Study of Parents and Children' reported on children’s snoring, mouth breathing, and witnessed apnea at ≥2 surveys at 6, 18, 30, 42, 57, and 69 months, and completed the 'Strengths and Difficulties' questionnaire at 4 (n = 9140) and 7 (n = 8098) years. Cluster analysis produced 5 “Early” (6–42 months) and “Later” (6–69 months) symptom trajectories (“clusters”). Adverse behavioural outcomes were defined by top 10th percentiles on 'Strengths and Difficulties' questionnaire total and subscales, at four and seven years, in multivariable logistic regression models.
RESULTS: The SDB clusters predicted ≈20% to 100% increased odds of problematic behaviour, controlling for 15 potential confounders. Early trajectories predicted problematic behaviour at seven years equally well as at four years. In later trajectories, the “Worst Case” cluster, with peak symptoms at 30 months that abated thereafter, nonetheless at seven years predicted hyperactivity (1.85 [1.30–2.63]), and conduct (1.60 [1.18–2.16]) and peer difficulties (1.37 [1.04–1.80]), whereas a “Later Symptom” cluster predicted emotional difficulties (1.65 [1.21–2.07]) and hyperactivity (1.88 [1.42–2.49]). The two clusters with peak symptoms before 18 months that resolve thereafter still predicted 40% to 50% increased odds of behaviour problems at seven years.
CONCLUSIONS: In this large, population-based, longitudinal study, early-life SDB symptoms had strong, persistent statistical effects on subsequent behaviour in childhood. Findings suggest that SDB symptoms may require attention as early as the first year of life.