Sleep duration and sleep quality in people with and without intellectual disability: A meta-analysis

Abstract

This study provides the first meta-analysis of the purported differences in sleep time and sleep quality between people with and without intellectual disabilities. Twenty-one papers were identified that compared sleep time and/or sleep quality in people with and without intellectual disabilities. The meta-analysis of sleep time revealed that people with an intellectual disability slept for 18 min less, on average, than people without an intellectual disability. This significant difference was limited to those studies that tested groups of people with an identified genetic syndrome or developmental disorder. The analysis of sleep quality also concluded that people with intellectual disabilities experienced poorer sleep: In 93% of comparisons between groups, sleep was found to be of poorer quality in the group of people with intellectual disabilities. There were no differences found between studies that measured sleep objectively and those that used diary or questionnaire measures. Notably, most samples were drawn from populations of people with specified genetic syndromes or developmental disorders, rather than intellectual disability of heterogeneous origin. Similarly, most studies investigated sleep in children, although there was no evidence that the differences between the groups reduced during adulthood. Most studies used highly-regarded objective measures of sleep, such as polysomnography or actigraphy, although methodological flaws were evident in the identification of samples and the measurement of intellectual disability.

The Prevalence of Self-injurious Behaviour in Autism: A Meta-analytic Study

“…Each article was reviewed based on five quality criteria (see Supplementary Materials 1 for table) which control for key threats to validity in sample selection (sample identification, assessment of autism, measurement of IQ, measurement of adaptive functioning and measurement of self-injurious behaviour). The quality criteria were adapted from Richards et al, ( 2015 ) and Surtees et al ( 2018 ). For visual ease of interpretation, the criteria for each article were coded as red for a poor score of 0, yellow for an adequate score of 1, amber for a good score of 2 and green for an excellent score of 3.…”

Sleep disorders in rare genetic syndromes: a meta-analysis of prevalence and profile

“…Previous literature reviews suggest that genetic syndromes are related to elevated prevalence rates of diagnosable sleep disorders and 'general' sleep difficulties in ID. For example, Surtees et al [14] meta-analysed fifteen studies comparing sleep time of individuals with ID to TD comparison groups and found that individuals with ID slept for 18 minutes less per night. Secondary analysis revealed this difference in sleep quantity was isolated to the studies comparing TD individuals to individuals with genetic syndromes, rather than individuals with heterogeneous ID (ID not associated with a given genetic syndrome, but resulting from a range of prenatal, perinatal and postnatal causes).…”

Sleep problems in adults with Down syndrome and their family carers

“…Inadequate or poor quality sleep is associated with disturbed emotional state or behaviour such as anxiety, depression and irritability and also impaired cognitive function and performance. Such disturbance is common in the general population but certain groups are at particularly high risk, including people with intellectual disabilities (Brylewski & Wiggs, ; Gunning & Espie, ; Surtees, Oliver, Jones, Evans, & Richards, ; van de Wouw, Evenhuis, & Echteld, ). The common condition of Down syndrome (DS) affecting around 1 in 1,000 live births worldwide, is a case in point.…”