Definitions of sleeplessness in children with attention-deficit hyperactivity disorder (ADHD): implications for mothers' mental state, daytime sleepiness and sleep-related cognitions.

BACKGROUND: Sleep disturbances are common in children with attention-deficit hyperactivity disorder (ADHD). Sleeplessness is frequently reported although results are inconsistent perhaps because different definitions for it are applied. This study looked at maternal functioning and child objective sleep patterns in relation to different definitions of sleeplessness in children with ADHD. METHODS: The study included 45 children (aged 3-14 years) with ADHD and their mothers. Sleeplessness was defined according to: (i) yes/no report of whether mothers thought their children had a problem with sleeplessness (Maternal definition MD) and (ii) mothers' responses to a quantitative standardized questionnaire (Quantitative definition QD) designed to detect the frequency and duration of parent-reported problems with settling, night waking and early waking. Objective sleep patterns were also assessed by means of actigraphy. Maternal mental health, daytime sleepiness and cognitions related to child sleep were assessed by questionnaire. RESULTS: Both definitions appeared to tap similar although slightly different constructs. There were no group differences in objective sleep patterns. Maternal mental health was found to be significantly worse in the mothers who considered their child to be sleepless (MD) (P < 0.025), but not in those mothers whose child was found to be sleepless according to the standardized criteria (QD). Maternal sleepiness did not differ between groups. For both categories of sleepless children (MD and QD), the mothers had significantly more doubts about their competency as a parent (P < 0.01 and P < 0.025, respectively) compared to mothers of children without sleeplessness. CONCLUSIONS: Two different maternal assessments of child sleeplessness in children with ADHD may assess subtly different constructs, but both may provide useful information about potential problems across the family.

Melatonin for sleep problems in children with neurodevelopmental disorders: randomised double masked placebo controlled trial.

OBJECTIVE: To assess the effectiveness and safety of melatonin in treating severe sleep problems in children with neurodevelopmental disorders. DESIGN: 12 week double masked randomised placebo controlled phase III trial. SETTING: 19 hospitals across England and Wales. PARTICIPANTS: 146 children aged 3 years to 15 years 8 months were randomised. They had a range of neurological and developmental disorders and a severe sleep problem that had not responded to a standardised sleep behaviour advice booklet provided to parents four to six weeks before randomisation. A sleep problem was defined as the child not falling asleep within one hour of lights out or having less than six hours' continuous sleep. INTERVENTIONS: Immediate release melatonin or matching placebo capsules administered 45 minutes before the child's bedtime for a period of 12 weeks. All children started with a 0.5 mg capsule, which was increased through 2 mg, 6 mg, and 12 mg depending on their response to treatment. MAIN OUTCOME MEASURES: Total sleep time at night after 12 weeks adjusted for baseline recorded in sleep diaries completed by the parent. Secondary outcomes included sleep onset latency, assessments of child behaviour, family functioning, and adverse events. Sleep was measured with diaries and actigraphy. RESULTS: Melatonin increased total sleep time by 22.4 minutes (95% confidence interval 0.5 to 44.3 minutes) measured by sleep diaries (n=110) and 13.3 (-15.5 to 42.2) measured by actigraphy (n=59). Melatonin reduced sleep onset latency measured by sleep diaries (-37.5 minutes, -55.3 to -19.7 minutes) and actigraphy (-45.3 minutes, -68.8 to -21.9 minutes) and was most effective for children with the longest sleep latency (P=0.009). Melatonin was associated with earlier waking times than placebo (29.9 minutes, 13.6 to 46.3 minutes). Child behaviour and family functioning outcomes showed some improvement and favoured use of melatonin. Adverse events were mild and similar between the two groups. CONCLUSIONS: Children gained little additional sleep on melatonin; though they fell asleep significantly faster, waking times became earlier. Child behaviour and family functioning outcomes did not significantly improve. Melatonin was tolerable over this three month period. Comparisons with slow release melatonin preparations or melatonin analogues are required. TRIAL REGISTRATION: ISRCT No 05534585.

The use of MElatonin in children with neurodevelopmental disorders and impaired sleep: a randomised, double-blind, placebo-controlled, parallel study (MENDS).

BACKGROUND: Difficulties in initiating and maintaining sleep are common in children with neurodevelopmental disorders. Melatonin is unlicensed in children yet widely prescribed for sleep problems. OBJECTIVE: To determine whether or not immediate-release melatonin is beneficial compared with placebo in improving total duration of night-time sleep in children with neurodevelopmental problems. DESIGN: Randomised, double-blind, placebo-controlled, parallel study. SETTING: Hospitals throughout England and Wales recruited patients referred by community paediatricians and other clinical colleagues. PARTICIPANTS: Children with neurodevelopmental problems aged from 3 years to 15 years 8 months who did not fall asleep within 1 hour of lights out or who had < 6 hours of continuous sleep. Before randomisation, patients meeting eligibility criteria entered a 4- to 6-week behaviour therapy period in which a behaviour therapy advice booklet was provided. Sleep was measured using sleep diaries and actigraphy. After this period the sleep diaries were reviewed to determine if the sleep problem fulfilled the eligibility criteria. Eligible participants were randomised and followed for 12 weeks. INTERVENTIONS: Melatonin or placebo capsules in doses of 0.5 mg, 2 mg, 6 mg and 12 mg for a period of 12 weeks. The starting dose was 0.5 mg and the dose could be escalated through 2 mg and 6 mg to 12 mg during the first 4 weeks, at the end of which the child was maintained on that dose. MAIN OUTCOME MEASURES: The primary outcome was total night-time sleep time (TST) calculated using sleep diaries at 12 weeks compared with baseline. Secondary outcome measures included TST calculated using actigraphy data, sleep-onset latency (SOL) (time taken to fall asleep), sleep efficiency, Composite Sleep Disturbance Index score, global measure of child's sleep quality, Aberrant Behaviour Checklist, Family Impact Module of the Pediatric Quality of Life Inventory (PedsQL™), the Epworth Sleepiness Scale, number and severity of seizures and adverse events. Salivary melatonin concentrations and association of genetic variants with abnormal melatonin production were also investigated. RESULTS: A total of 275 children were screened to enter the trial; 263 (96%) children were registered and completed the 4- to 6-week behaviour therapy period and 146 (56%) children were randomised, of whom 110 (75%) contributed data for the primary outcome. The difference in TST time between the melatonin and placebo groups adjusted for baseline was 22.43 minutes [95% confidence interval (CI) 0.52 to 44.34 minutes; p = 0.04] measured using sleep diaries. A reduction in SOL, adjusted for baseline, was seen for melatonin compared with placebo when measured by sleep diaries (-37.49 minutes, 95% CI -55.27 to -19.71 minutes; p < 0.0001) and actigraphy (-45.34 minutes, 95% CI -68.75 to -21.93 minutes; p = 0.0003). There were no significant differences between the two groups in terms of the reporting of adverse events. The results of other secondary outcomes favoured melatonin but were not statistically significant. CONCLUSIONS: On average, the children treated with melatonin slept 23 minutes longer than those in the placebo group; however, the upper limit of the confidence interval was less than 1 hour, the minimum clinically worthwhile difference specified at the outset of the trial. Melatonin is effective in reducing SOL in children with neurodevelopmental delay by a mean of 45 minutes; a value of 30 minutes was specified a priori to be clinically important. Future studies should be conducted over longer periods and directly compare different formulations of melatonin with conventional hypnotic and sedative medications. It would also be important to study groups of children with specific neurological disorders. TRIAL REGISTRATION: Current Controlled Trials ISRCTN05534585. FUNDING: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 16, No. 40. See the HTA programme website for further project information.

Sleep behaviour in children with developmental co-ordination disorder.

BACKGROUND: Children with developmental co-ordination disorder (DCD) experience significant difficulty in the performance of everyday movement skills in the absence of obvious neurological, sensory or intellectual impairment. They often underachieve academically and have higher rates of anxiety than their typically developing peers. Such factors are known to be associated with sleep problems in other clinical populations but the sleep patterns of children with DCD have not been examined. Information about the frequency and nature of sleep problems in DCD will aid our understanding of this developmental disorder. It may also be clinically helpful, alerting clinicians to potential difficulties so that these can be identified early and appropriate support offered. OBJECTIVE: To examine sleep behaviour of children with DCD compared with typically developing control children. METHODS: Two groups of 16 boys aged 8 to 12 years (M = 10.28, SD = 1.28) participated: (1) the DCD group had Movement ABC-2 Checklist scores below the 5th percentile; (2) an age-matched control group of typically developing children had Movement ABC-2 Checklist scores above the 15th percentile. Parents of children from both groups completed the Children's Sleep Habits Questionnaire. RESULTS & DISCUSSION: The total sleep disturbance score was significantly higher for children with DCD compared with the control group (U= 24, P < 0.001). Subscale scores indicated particular problems with bedtime resistance (U= 77.5, P < 0.05), parasomnias (U= 28.5, P < 0.001) and daytime sleepiness (U= 58.00, P < 0.01). There were no differences between the groups for sleep onset delay, sleep duration, night wakings and sleep-disordered breathing. These preliminary results suggest that sleep patterns of children with DCD may be of clinical relevance and are worthy of further investigation.

Behavioural aspects of children's sleep.

There is good empirical evidence that behavioural factors play a role in the onset/maintenance of many childhood sleeplessness problems and that behaviour therapy can be used as an effective form of management. There is a smaller, but growing, literature supporting the idea that behavioural interventions may also play a significant role in the management of other types of sleep disorder (eg, rhythmic movement disorders, arousal disorders, nightmares and circadian rhythm sleep disorders), and this is an area ripe with research possibilities. This review outlines the nature of behavioural aspects of children's sleep and how these might be addressed by behaviour therapy. Clinical considerations concerned with the use of behavioural therapy are also highlighted (eg, the role of behaviour therapy as an adjunct to other treatments, its use with special populations, and how it might be delivered to families).

Psychological consequences of road traffic accidents for children and their mothers.

BACKGROUND: Little is known about the psychological and behavioural consequences of road traffic accidents for children. The study aimed to determine the outcome of road traffic accidents on children and their mothers. METHOD: A 1-year cohort study of consecutive child attenders aged 5-16 years at an Accident and Emergency Department. Data were extracted from medical notes and from interview and self-report at baseline, 3 months and 6 months. RESULTS: The children had an excellent physical outcome. Fifteen per cent suffered acute stress disorder; 25% suffered post-traumatic stress disorder at 3 months and 18% at 6 months. Travel anxiety was frequent. Post-traumatic consequences for mothers were common. CONCLUSION: Psychological outcome was poor for a minority of children and associated with disability, especially for travel. There were significant family consequences. There is a need for changes in clinical care to prevent, identify and treat distressing and disabling problems.

The relative efficacy of two brief treatments for sleep problems in young learning disabled (mentally retarded) children: a randomised controlled trial.

BACKGROUND: Settling and night waking problems are particularly prevalent, persistent, and generally considered difficult to treat in children with a learning disability, although intervention trials are few. Scarce resources, however, limit access to proven behavioural treatments. AIMS: To investigate the efficacy of a media based brief behavioural treatment of sleep problems in such children by comparing (1) face-to-face delivered treatment versus control and (2) booklet delivered treatment versus controls. METHODS: The parents of 66 severely learning disabled children aged 2-8 years with settling and/or night waking problems took part in a randomised controlled trial with a wait-list control group. Behavioural treatments were presented either conventionally face-to-face or by means of a 14 page easy to read illustrated booklet. A composite sleep disturbance score was derived from sleep diaries kept by parents. RESULTS: Both forms of treatment were almost equally effective compared with controls. Two thirds of children who were taking over 30 minutes to settle five or more times per week and waking at night for over 30 minutes four or more times per week improved on average to having such settling or night waking problems for only a few minutes or only once or twice per week (H = 34.174, df = 2, p<0.001). These improvements were maintained after six months. CONCLUSIONS: Booklet delivered behavioural treatments for sleep problems were as effective as face-to-face treatment for most children in this population.

Behavioural treatment for sleep problems in children with severe intellectual disabilities and daytime challenging behaviour: effect on mothers and fathers.

OBJECTIVES: The study aimed to assess the mental state of mothers and fathers following successful behavioural intervention for sleep problems in such children. DESIGN: A randomized controlled trial of behavioural interventions for sleep problems. METHODS: Parents of 15 children with severe intellectual disabilities, severe sleep problems, and challenging daytime behaviour received treatment for the child's sleep problem and were compared with 15 controls who received no treatment. Parental stress, sleepiness, locus of control, perceived control, and satisfaction with aspects of sleep were assessed. RESULTS: Successful treatment benefited the mothers, reducing stress, increasing perceived control and making them more satisfied with their sleep, their child's sleep, and their ability to cope with their child's sleep. Positive effects in the fathers were limited to increased satisfaction with their own sleep and their child's sleep; fathers tended to feel less control following treatment. Maternal sleepiness and perceived control, and aspects of parental satisfaction showed improvements in both the treatment and control groups. CONCLUSION: The effects of childhood sleep problems, and their resolution using behavioural interventions, may be different in mothers and fathers. This highlights the need to assess all family members in order to gain a greater understanding of how best to help families as a whole. The improvements in both control and treatment groups indicate that there may be non-specific effects of taking part in the study that played a therapeutic role.

Alterations in sleep physiology in young children with insulin-dependent diabetes mellitus: relationship to nocturnal hypoglycemia.

OBJECTIVES: To examine the effect of diabetes per se and nocturnal hypoglycemia on sleep in children with insulin-dependent diabetes mellitus (IDDM). DESIGN: Overnight polysomnography was performed on 3 occasions in 29 children with IDDM - twice during metabolic profiling. Sleep data were analyzed from 14 children (median [range], 8.7 [5.9 to 12.9] years) with a night of hypoglycemia and a nonhypoglycemic night. Seven children in the control group (9 [5.6 to 11.4] years) underwent 2 nights of polysomnography, once during metabolic profiling (to assess the effects of metabolic profiling), and 15 members of the control group had polysomnography only (to assess the effects of diabetes per se and to compare with the index group). RESULTS: Children with IDDM had disrupted sleep compared with the control group (short wakes, percentage of sleep time, 0.8 [0.5 to 1.9] vs 0.0 [0.0 to 0.3], median [interquartile range], IDDM vs control group, respectively, P =.001; long wakes, 1.2 [0.7 to 3. 0] vs 0.0 [0.0 to 0.0], P =.033; total number of wakes, 6 [3.5 to 11. 5] vs 1 [0 to 2], P =.002). Blood sampling disrupted sleep with increased long wakes as percentage of sleep time (0.3 [0.0 to 3.8] vs 4.3 [3.1 to 16.9], nonsampling vs sampling night, respectively, P =.003). Episodes of hypoglycemia were profound, with a glucose nadir of 2.0 [1.4 to 3.3] mmol/L (35.0 [24.5 to 57.8] mg/dL) and prolonged, 308 [30 to 630] minutes, with no effect on sleep. CONCLUSIONS: Children with diabetes had disrupted sleep compared with a control group, but there was no effect of profound nocturnal hypoglycemia on sleep quality. J Pediatr 2000;137:233-8)

Evaluation of the oxyrase OxyPlate anaerobe incubation system.

The Oxyrase OxyPlate anaerobe incubation system was evaluated for its ability to support the growth of clinically significant anaerobic bacteria previously identified by the Anaerobe Reference Laboratory at the Centers for Disease Control and Prevention. The results were compared with those obtained with conventional anaerobe blood agar plates incubated in an anaerobe chamber. We tested 251 anaerobic bacterial strains. Plates were read at 24, 48, and 72 h; growth was scored by a numerical coding system that combines the degree of growth and the colony size. Organisms (number of strains tested) used in this study were Actinomyces (32), Anaerobiospirillum (8), Bacteroides (39), Campylobacter (8), Clostridium (96), Fusobacterium (12), Leptotrichia (8), Mobiluncus (8), Peptostreptococcus (16), and Propionibacterium (24). At 24 h, 101 (40.2%) of the 251 strains tested showed better growth with the anaerobe chamber than with the OxyPlate system, 10 (4.1%) showed better growth with the OxyPlate system, and the remaining 140 (55. 8%) showed equal growth with both systems. At 48 h, 173 (68.9%) showed equal growth with both systems, while 78 (31.1%) showed better growth with the anaerobe chamber. At 72 h, 176 (70.1%) showed equal growth with both systems, while 75 (29.9%) showed better growth with the anaerobe chamber. The OxyPlate system performed well for the most commonly isolated anaerobes but was inadequate for some strains. These results indicate that the Oxyrase OxyPlate system was effective in creating an anaerobic atmosphere and supporting the growth of anaerobic bacteria within 72 h. OxyPlates would be a useful addition to the clinical microbiology laboratory lacking resources for traditional anaerobic culturing techniques.

A systematic review of treatments for settling problems and night waking in young children.

OBJECTIVES: To assess the efficacy of treatments for settling problems and night waking in young children. DESIGN: A systematic review of randomised controlled trials of interventions for settling problems and night waking in young children. SETTING: Electronic bibliographic databases and references on identified papers, hand searches, and personal contact with specialists. SUBJECTS: Children aged 5 years or less who had established settling problems or night waking. INTERVENTIONS: Interventions had to be described and a placebo, waiting list, or another intervention needed to have been used as a comparison. Interventions comprised drug trials or non-drug trials. MAIN OUTCOME MEASURES: Number of wakes at night, time to settle, or number of nights in which these problems occurred. RESULTS: Drugs seemed to be effective in treating night waking in the short term, but long term efficacy was questionable. In contrast, specific behavioural interventions showed both short term efficacy and possible longer term effects for dealing with settling problems and night waking. CONCLUSIONS: Given the prevalence and persistence of childhood sleep problems and the effects they can have on children and families, treatments that offer long lasting benefits are appealing and these are likely to be behavioural interventions.

Behavioural treatment for sleep problems in children with severe learning disabilities and challenging daytime behaviour: effect on daytime behaviour.

The study aimed to investigate a group of children with severe learning disabilities, challenging daytime behaviour, and severe sleep problems to see if successful behavioural treatment of the children's sleep problems resulted in reduced daytime challenging behaviour as reported by mothers and teachers. A randomised controlled trial of behavioural interventions for the children's sleep problems was conducted (N = 30). The intervention group received an individually tailored behavioural programme and were supported by telephone calls from the therapist. Baseline assessments of the children's behaviour were made using the Aberrant Behavior Checklist and were repeated 1 month and 3 months after the start of intervention. There were no behavioural changes that were specific to children in the treatment group. However, improvements in some behaviours were seen in both the intervention and the control group at the 1-month and 3-month assessments and there was agreement between mothers' and teachers' reports for many of these changes. The results suggest that nonspecific effects of participating in the study (including an increased sleep duration, which was seen in both groups), rather than resolution of sleep problem per se, may have a beneficial effect on child behaviour and these factors need to be identified for therapeutic use.

Sleep problems and daytime challenging behaviour in a community-based sample of adults with intellectual disability.

The present study aimed to explore associations between sleep problems and daytime challenging behaviour in a community sample of adults with intellectual disability. Sleep and behaviour questionnaires were completed for 205 people aged 18 years or over living in health- or social-services-managed community housing. This sample represented an 86% return rate. The informants were carers and the individuals themselves where possible. Seventy-nine people with sleep problems were compared with 121 individuals without this difficulty; five people were excluded from the analysis. Individuals with sleep problems displayed significantly more daytime irritability, stereotypy and hyperactivity than those without sleep problems. Individuals displaying clinically significant aggression/temper, self-injury and screaming were significantly more likely to have a concurrent sleep problem, and these forms of challenging behaviour were significantly more severe in the sleep problem group. Associations between sleep problems and daytime challenging behaviour exist in this population, although the nature of any links remains unclear and should be the attention of future research.

Behavioural treatment for sleep problems in children with severe learning disabilities and challenging daytime behaviour: effect on sleep patterns of mother and child.

Children with sleep problems present serious management problems to their parents. Such children are also more likely to have additional problems, behavioural disturbance being particularly common. This randomized controlled trial of behavioural interventions for the children's sleep problems was conducted to explore the efficacy and mechanisms of treatment in children with the most extreme forms of problems: severe learning disabilities, severe sleep problems and severe daytime challenging behaviour. Fifteen index families received behavioural advice for the child's sleep problem and compared with 15 matched controls who received no such advice. Repeat assessments of the children's and mothers' sleep were made by parental report as well as actometry. Objective changes in the children's sleep quality and quantity were not seen after treatment. However, mothers in the treatment group reported improvements in the children's sleep problems and had an increased sleeping time themselves following treatment. The results indicate that sleep problems can be successfully treated in this group of children, although the mechanisms of treatment may not be as direct as supposed. This has implications for understanding of sleep problems in children with learning disabilities and also for clinical practice, when considering ways of offering help to these highly 'challenged' families.

Sleep and psychological disturbance in nocturnal asthma.

Subjective and objective sleep disturbance was studied in children with nocturnal asthma. Relations between such disturbance and daytime psychological function were also explored, including possible changes in learning and behaviour associated with improvements in nocturnal asthma and sleep. Assessments included home polysomnography, parental questionnaires concerning sleep disturbance, behaviour, and mood and cognitive testing. Compared with matched controls, children with asthma had significantly more disturbed sleep, tended to have more psychological problems, and they performed less well on some tests of memory and concentration. In general, improvement of nocturnal asthma symptoms by changes in treatment was followed by improvement in sleep and psychological function in subsequent weeks. The effects of asthma on sleep and the possible psychological consequences are important aspects of overall care.

A questionnaire survey of sleep and night-time behaviour in a community-based sample of adults with intellectual disability.

Two hundred and five people with intellectual disability, aged 18 years or over, and living in health- or social-services-managed community housing, completed sleep and behaviour questionnaires. An 85.7% return rate was achieved. Settling problems were present in 26.8% and night waking in 55.6% of the subjects. Parasomnias were present in 14% of subjects and 15% of the sample showed some features associated with sleep-related breathing problems. Factors associated with sleep-related problems included gender, aetiology of intellectual disability, epilepsy, treatment with antiepileptic medication, evening caffeine consumption, nocturnal urinary incontinence and ability to communicate. Significant sleep-related problems were demonstrated in this population; some of these problems might be avoided by simple measures.

Sleep disorders and their relationship to psychological disturbance in children with epilepsy.

By means of parental questionnaires, sleep disturbances were assessed in 79 schoolchildren with epilepsy (mean age 10.12, range 5-16 years) for comparisons with 73 healthy control children matched for gender and to within a maximum of 6 months of age. The daytime behaviour of the children with epilepsy was also assessed by questionnaire. The children with epilepsy were considered representative of such children under general paediatric care. Sleep disturbance was classified into five basic types (poor quality sleep, anxieties about sleep, disturbances during sleep, symptoms of disordered breathing during sleep and short duration sleep) and the behaviour questionnaire provided scores on five factors (conduct problems, hyperactivity, attention problems, anxiety and physical complaints). Compared with normal controls children with epilepsy showed much higher rates of sleep disorders, particularly poor quality sleep and anxieties about sleep. In children aged 5-11 years associations were found between disturbed daytime behaviour and sleep problems, particularly poor quality sleep. There was also a significant association between seizure frequency and anxieties about sleeping. This study highlights the potentially serious psychological and other developmental implications of persistent sleep disturbance to children with epilepsy, and the need for further research on specific types of epilepsy with careful identification of the nature of both sleep disturbance and related psychological dysfunction.

Clinical services for sleep disorders.

Children's sleep disorders are common and often harmful to development and well being. The clinical services available to affected children and their families need to be improved. At present, professional interest and expertise in sleep disorders medicine is severely limited by the paucity of appropriate teaching and training. The work of a mainly tertiary sleep disorders clinic was reviewed, which showed that accurate diagnosis of a wide range of sleep disorders is possible, and that treatment needs can be specified. Although families appreciated such assessment, the outcome was unsatisfactory in many cases, often because treatment recommendations were not implemented by referrers. Reasons for this appear to include poor communication between referrers and families, and unavailability of treatment resources. A three tier system of service provision is proposed to improve this situation, which rests essentially on better professional training in the sleep disorders field.

Home polysomnography norms for children.

Home polysomnography (PSG) by means of ambulatory monitoring systems has distinct advantages over sleep laboratory recordings, especially for children. However, normative data have been lacking. Norms for conventional PSG variables were compiled for 60 children age 5-16 years using the Oxford Medilog ambulatory monitoring system. Recordings were confined to a single night in view of previous demonstrations that the sleep on the first night is not significantly affected by the recording procedure. The results are presented in 5 age subgroups. Broad comparisons with published laboratory PSG norms for children of the same ages suggest that in home recordings sleep duration is longer, and slow wave sleep is much more pronounced with a commensurate reduction in stage 2 NREM sleep. That is, sleep quality and quantity appears better at home even when adaptation to the laboratory situation has been promoted. These new normative data are considered valuable for both clinical and research purposes where physiological sleep studies in children are required.