Sleep duration and efficiency from 6 to 18 years of age in a birth cohort

Healthy sleep comprises a multidimensional sleep-wake pattern, adapted to individual, social and environmental demands, which promotes physical and mental well-being.

To describe sleep multitrajectories from 6 to 18 years of age.

Population-based birth cohort using information from 4231 participants assessed at birth and at 6, 11, 15, and 18 years of age. Bedtime, wake-up time, sleep duration, and sleep efficiency were measured through actigraphy. Group-based multitrajectory models (GBMTM) were applied to jointly explore the longitudinal changes in bedtime, wake-up time, sleep duration, and sleep efficiency over time. Maternal and child characteristics at birth were used to describe prevalence (with 95 % confidence interval) of sleep multitrajectories.

3595, 3547, 1940, and 3447, respectively, at ages 6, 11, 15, and 18 years had information on sleep parameters, and 2412 were included in the multitrajectory analysis. In the entire cohort, sleep duration decreased from 7.54 h at 6 years to 6.84, 6.14, and 6.42 h, respectively, at 11, 15, and 18 years, and sleep efficiency improved with age from 81.0 % at 6 years to 85.0 % at 18. Three multitrajectory groups containning the simultaneous analysis on the four sleep parameters were defined: G1, G2 and G3, comprising, respectively, 28.8 %, 33.8 %, and 37.4 % of the sample. At 18 years, only adolescents from G3 achieved sleep duration and efficiency within the recommended range for age (respectively, 7.60 h/day and 86.0 %). Female adolescents and those with low birth weight had a greater likelihood of belonging to G3.

Although adolescents from the three groups presented an acceptable sleep duration at 6 years, by the end of adolescence only 37.4 % of them achieved the recommended sleep duration and efficiency needed for a good health and well-being, as defined by the United States National Sleep Foundation.