How long do preschoolers in Aotearoa/New Zealand sleep? Associations with ethnicity and socioeconomic position

Objectives: To investigate potential sleep inequities in preschoolers in Aotearoa/New Zealand, by examining sleep durations and week/weekend sleep duration differences of Māori (indigenous) and non-Māori preschoolers; and independent associations between ethnicity (child and maternal), socioeconomic position (SEP) and preschoolers' sub-optimal and inconsistent week/weekend sleep durations.

Design: Cross-sectional analysis of questionnaire data from the Moe Kura: Mother and Child, Sleep and Wellbeing in Aotearoa/New Zealand longitudinal study when children were 3 to 4 years old.

Participants: 340 Māori and 570 non-Māori preschoolers and their mothers.

Measurements: Measures included preschoolers' usual nighttime sleep duration on week nights (week nighttime sleep) and weekends (weekend nighttime sleep); usual sleep duration across 24 hours, including naps, on week nights (week sleep [24 h]) and weekends (weekend sleep [24 h]) (≪10 h/10-13 h/≫13 h); and the difference between week and weekend sleep durations per 24 hours (sleep [24 h] difference) (≫1 h/≤1 h). Log-binomial regression models investigated associations between child and maternal characteristics and sleep duration measures. Child models included child ethnicity, child gender and child SEP (area and individual socioeconomic deprivation). Maternal models included maternal ethnicity, maternal age and maternal SEP (area and individual socioeconomic deprivation).

Results: Ethnicity and low SEP were independently associated with week day sleep (24 h) ≪10 h, weekend sleep (24 h) ≪10 h, and with sleep (24 h) difference ≫1 h.

Conclusions: Ethnic and socioeconomic inequities in sleep durations are evident as early as 3 to 4 years of age in NZ, highlighting the importance of addressing the socio-political drivers of sleep inequities early in the life course.