Background: Individual differences in paediatric sleep duration and sleep phase preferences have been clearly identified and could be described as different ‘phenotypes’ of sleepers. Understanding these differences impacts treatment planning. There is a paucity of empirical evidence regarding sleep genotypes in Australian children and even less in Australian Indigenous children. This is important given the health education and equity gap between indigenous and non-indigenous children.

Methods: Data for 513 children (7 – 9 years; 52% male) were sourced from the Australian Longitudinal Study of Indigenous Children (LSIC) and the National Assessment Program - Literacy and Numeracy (NAPLAN). Latent class analysis were used to determine classes of sleep schedules taking into account sleep duration, bedtimes, waketimes and variability in sleep schedules from week to weekends controlling for SES and family demographics. General linear models were used to associations between sleep and NAPLAN scores.

Results: Five sleep schedule phenotypes were identified: Normative sleep; Early Risers; Long Sleep; Variable Sleep; and, Short Sleep. NAPLAN scores differed significantly between some of the classes, with the Short Sleep class having significantly poorer grammar and numeracy performance compared with Long Sleepers. The Variable Sleep class also had significantly poorer numeracy performance compared with Long Sleepers. Maternal education and geographical remoteness were associated with poorer sleep.

Conclusions: Short sleep and highly variable sleep are associated with poorer performance on numeracy and literacy in Indigenous children. Sleep scheduling is modifiable with increased awareness and education as a first step, so this offers opportunity for improvement in sleep and thus downstream performance outcomes for these children. Further studies in non indigenous children may produce similar findings and present similar opportunities.