Effects of Parent-based Educational Programme for Sleep Problems in Children With Autism Spectrum Disorder (ASD): A Randomized Controlled Trial
Phase: NA
Conditions: ASD, Insomnia
Sponsor: The University of Hong Kong

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STUDY PROTOCOL 
 
Protocol Title 
Effects of Parent-based Educational Programme for Sleep Problems in Children with 
Autism Spectrum Disorder: A Randomized Controlled Trial 
 
Protocol Identifying Number: Version 2 
 
Date: 8 May 2020 
 
Principle Investigator 
Mr. IP Yee Ting 
Clinical Psychologist in charge 
Department of Clinical Psychology 
The Duchess of Kent Children’s Hospital at Sandy Bay 
iyt003@ha.org.hk 
Tel: 852-29740351 
 
Co-Investigator 
Dr. LEE So-lun 
Chief of Service (Paediatrics) 
Department of Paediatrics & Adolescent Medicine 
The Duchess of Kent Children’s Hospital at Sandy Bay / Queen Mary Hospital / The 
University of Hong Kong 
slleem@hku.hk 
Tel: 852-29740317 
 
Dr. Shirley Xin LI 
Assistant Professor 
Department of Psychology 
The University of Hong Kong 
shirley.li@hku.hk 
Tel: 852-39177035 
 

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Background Information 
Sleep is important for healthy development for all children. Previous studies consistently 
documented that the prevalence rate of sleep problems in children with 
neuro-developmental disorders such as Autism Spectrum Disorder (ASD) are high 
(Corkum, Davidson, Tan-MacNeill, & Weiss, 2014; Richdale & Schreck, 2009). 
Common sleep problems including bedtime resistance, sleep-onset delay, nightwaking 
and early morning awakening were reported in 53% to 78% in children with ASD 
(Couturier et al., 2005; Krakowiak, Goodlin‐Jones, Hertz‐Picciotto, Croen, & Hansen, 
2008). Sleep problems in young children were commonly reported across different 
nationalities and cultures (Lo, 2016; Mindell, Sadeh, Kohyama, & How, 2010). There 
were few published studies on the prevalence of sleep problems in children in Hong 
Kong. Ng et al. (2005) reported the prevalence of common sleep symptoms including 
sleep teeth grinding (20.5%), habitual snoring (10.9%), nocturnal enuresis (5.1%) and 
witnessed sleep apnea (1.5%) in a sample of 3,047 6- to12- year-old children. However, 
data on behavioral sleep problems were not collected. Tso et al. (2016) found that only 
11% of preschoolers had the recommended 11-12 hours of sleep per day. Associations 
between sleep deprivation and lower school readiness, more hyperactivity and inattention, 
and less prosocial behavior were evident. A local study conducted by Doo and Yun 
investigated sleep problems in preschool children with Pervasive Developmental 
Disorders (PDD) (Doo & Wing, 2006). They reported that the prevalence of 
parent-defined sleep problems in various sleep domains ranged from 9.3 to 45.6%, with 
67.9% of children having significant problems in at least one sleep domain. The most 
common problems reported were bedtime resistance and parasomnias. 
 
Previous research has shown the negative impacts of sleep problems in children including 
typically developing children (Beebe, 2006) as well as specific groups of children with 
neuro-developmental disorders including ASD (Schneider, Lam, & Mahone, 2016). 
Analyses of data of three cross-sectional cohorts in a Canadian National Longitudinal 
Study showed that sleep problems were strong correlate of, and might exacerbate, child 
emotional and behavioral problem (Reid, Hong, & Wade, 2009). Turnbull and colleagues 
have done an extensive review on behavioral problems and development of executive 
functions (EF) in children with behavioral sleep problems (Turnbull, Reid, & Morton, 
2013). They proposed that EF might be particularly vulnerable to the effects of these 
common childhood sleep problems: behavioral problems associated with common sleep 
problems suggested poor self-regulation in the context of sleep loss, and developing EF 
skills played important roles in self-regulation. Negative correlates of children’s sleep 
problems identified included inattention and aggressive behavior (Lo, 2016), poor 
academic performance and bad conduct (Ng et al., 2005), and lower school readiness 

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(Tso et al., 2016) in samples of Chinese children. On the other hand, child’s poor sleep 
habits were found to bring negative impacts to their parents as well. Parental stress was 
one of the common outcomes related to children sleep problems (Meltzer & Mindell, 
2007). Parents of children with ASD were also known to have challenges in maintaining a 
positive sense of well-being and self-efficacy (Kuhn & Carter, 2006). There was one 
study suggesting that the improvement in child’s sleep habits relates with improvement in 
parental sense of competence and satisfaction (Malow et al., 2014). 
 
Previous literature showed that sleep-focused behavioral interventions could result in 
lasting beneficial effects on sleep with minimal adverse effects (Malow et al., 2012; 
Meltzer & Mindell, 2007; Vriend, Corkum, Moon, & Smith, 2011). However, few 
treatment studies have measured changes or improvements in daytime functioning of 
children with ASD, or mainly based on parent’s report as outcome measures of sleep 
treatment (Turnbull et al., 2013). Data obtained in this RCT would contribute valuable 
information to the academic knowledge, and propose important implication for relevant 
treatment to children with ASD. 
 
Study Objective and Purpose 
The objective of the current study is to conduct a randomized controlled trial (RCT) for 
children with ASD, in order to examine the effectiveness of a Parent-based Sleep 
Educational Programme, with outcomes of parent-report measures and child’s 
performance on tasks involving executive functions. It is hypothesized that parents’ sleep 
quality and child’s sleep problems would be improved in the Treatment Group, as 
compared to Waitlist Treatment-As-Usual (TAU) control. As secondary outcomes, it is 
hypothesized that parents in the Treatment Group would show improvement in mood, 
quality of life, parenting stress and competence; while children in the Treatment Group 
would show improvement in executive functions and daytime functioning. 
 
Study Design 
The study is a randomized controlled trial (RCT) aiming to examine the effectiveness of a 
Parent-based Sleep Educational Programme. Target participants to be recruited are 
paediatric patients (aged 3 to 6 years old) with a clinical diagnosis of ASD, and their 
parent (aged 21 or above), who are attending paediatric developmental clinic or clinical 
psychology service at the Duchess of Kent Children’s Hospital at Sandy Bay. 
 
Data on patients’ and the family’s demographic information will be obtained from the 
parents. Parent of patients will be invited to complete a set of questionnaires on the 
child’s demographic information and measures on their child including sleep pattern and 

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sleep problems (Child’s Sleep Habits Questionnaire, CSHQ), executive functions 
(Behavior Rating Inventory of Executive Function – Preschool Version, BRIEF-P) and 
behavioral and emotional problems (Strengths and Difficulties Questionnaire, SDQ). 
Parents will also be asked to report their own quality of life (The 12-item Short Form 
Health Survey, SF-12v2), sleep quality (Insomnia Severity Index, ISI; The Pittsburgh 
Sleep Quality Index, PSQI), mood symptoms (Depression, Anxiety and Stress Scale - 21 
Items, DASS), parental stress level (Parental Stress Scale, PSS), and their sense of 
competence and satisfaction in childcare (Parenting Sense of Competence Scale, PSOC). 
Moreover, patients will be assessed using standardized tests on executive functions (Bug 
Search and Picture Memory Subtests from WPPSI-IV(HK), Statue subtest from NEPSY-2, 
and Conners K–CPT 2.  
 
Participants will then be randomly assigned into either Treatment Group or Waitlist 
Group. Parents and Children in both the Treatment Group and Waitlist Group will be 
interviewed individually by Clinical Psychologist (CP) (Week 0). Parent’s specific 
concerns on the child’s sleep issues will be explored. For parents in the Treatment Group, 
they will receive a Parent Sleep Educational Programme which consists of three weekly 
group sessions (Week 1-3) conducted by a CP on behavioral intervention for sleep 
problems. Programme content takes reference from materials developed by the HKU 
Sleep Research Clinic and Laboratory ("Empowering Parents to Help Children Sleep 
Better: Parent-based Sleep Education for Children with Autism Spectrum Disorders," 
2018) and evidence-based sleep educational materials from the relevant literature (Allen, 
Howlett, Coulombe, & Corkum, 2016; Autism Speaks Autism Treatment Network, 2019; 
Yu et al., 2015). Bi-weekly individual telephone support sessions will be conducted by a 
CP to support the parents and trouble-shoot the difficulties that parents may encounter 
when implementing the behavioural strategies to manage their child’s sleep problems (at 
Week 1, 3, 5 and 7). For children and parents in the Waitlist Group, they will be placed on 
waitlist while children continue to receive treatment-as-usual from multidisciplinary team 
of DKCAC (Paediatrician, Physiotherapist, Occupational Therapist, Speech Therapist, 
Social Worker etc.) and other available services in the community. 
 
Post-intervention review and assessment at Week 8-10 would be conducted with all 
parents and children (Treatment Group, Waitlist Group) by CP. Parents will be asked to 
fill in the same set of questionnaires measures; re-assessment on the standardized tests 
will also be conducted with the children. Parents in the Treatment Group will also be 
asked to fill in a post-intervention feedback survey. Parents in the Waitlist group will then 
be invited to join a Parent Sleep Educational Programme starting from Week 12. 
 

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Lastly, a 6-month post-intervention assessment (all instruments and standardized tests) 
would be conducted for parents and children in the Treatment Group. 
 
Figure 1 shows a schematic diagram of the study design and flowchart. 
 
Outcome Measures 
 
Child-related Measures: 
Measure of Sleep 
The Children’s Sleep Habit Questionnaire (CSHQ) is a parent-report questionnaire 
designed to assess common sleep problems in children. The 33-item CSHQ evaluates the 
child’s sleep based on behavior within eight different subscales: bedtime resistance, 
sleep-onset delay, sleep duration, sleep anxiety, night wakings, parasomnias, 
sleep-disordered breathing, and daytime sleepiness. Parents give responses from a scale 
of 1-3, with 3 indicating “usually”, 2 indicating “sometimes” and 1 indicating “rarely”. 
The scores are added up and a total score of 41 makes an effective cut-off for screening 
purposes as it correctly identiﬁed 80% of the clinical sample in the developers’ initial 
psychometric study. Internal consistency, test-retest reliability, sensitivity and specificity 
have been demonstrated. 
 
Measure of Emotional and Behavioural Problems 
The Strengths and Difficulties Questionnaire (SDQ) is a 25-item screening measure for 
emotional and behavioral problems in children and adolescents ages 2 to 3, and 4 to 17. It 
rated on a Likert-type scale and equally divided into five subscales: emotional symptoms, 
conduct problems, hyper-activity-inattention, peer problems, and prosocial behavior. The 
sum of the four subscales generates a total difficulties score. Validated Chinese version is 
available, with satisfactory reliability. 
 
Cognitive Performance 
The Behavior Rating Inventory of Executive Function-Preschool version (BRIEF-P) 
consists of 63 items that measure various behavioral manifestations of EF based on parent 
or teacher ratings, within the context of the child's everyday environment, in children 
ages 2 to 5 years old.25 The BRIEF-P covers the scales inhibit (I), shift (S), emotional 
control (EC), working memory (WM), and plan/organize (PO). These scales form three 
broad indexes: inhibitory self-control (ISC), flexibility (F), and emergent metacognition 
(EM), as well as one composite score, the global executive composite (GEC). The scale 
demonstrated high internal consistency reliability and moderate test-retest reliability 
 

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The Wechsler Preschool and Primary Scale of Intelligence™ - Fourth Edition (Hong 
Kong) (WPPSI-IV(HK)) is a measure of cognitive development for preschoolers and 
young children that's rooted in contemporary theory and research that also places a strong 
emphasis on child-friendly, developmentally appropriate features and includes new 
processing speed tasks, the addition of working memory subtests, an expanded factor 
structure. The Hong Kong edition, published in 2018, is locally validated with local 
norms. In the Bug Search subtest, children will be asked to use an ink dauber to mark the 
image of a bug in the search group that matches the target bug. Bug search is 
conceptually similar to Symbol Search, which involves short-term visual memory, 
visual-motor coordination, cognitive flexibility, visual discrimination, and concentration. 
In the Picture Memory Subtest, children will be asked to view a stimulus page of pictures 
for a specified time, then selects theses pictures from options on a response page. This 
subtest taps children’s visual working memory using the familiarize-recognize paradigm. 
 
The NEPSY-II consists of 32 subtests for use in a neuropsychological assessment with 
preschoolers, children, and adolescents. The Statue Subtest is designed to assess motor 
persistence and inhibition for children aged 3- to 6-year-old. Children will be asked to 
maintain a body position with eyes closed during a 75 second period and to inhibit the 
impulse to respond to sound distracters. 
 
The Conners Kiddie Continuous Performance Test 2nd Edition™ (Conners K-CPT 2™) 
assesses attention and inhibition in children ages 4 to 7 years old. Children will be 
instructed to press the keyboard space bar when target pictures are presented, while 
inhibiting their response when a specific picture (ball) is presented. Each child’s 
responses would be scored and resulted in performance in four aspects of attention: 
Inattentiveness, Impulsivity, Sustained Attention, and Vigilance. 
 
Parent-related Measures: 
 
Measures of Sleep 
The Pittsburg Sleep Quality Inventory (PSQI) is a self-rated questionnaire which assesses 
sleep quality and disturbances over a 1-month time interval. Nineteen individual items 
generate seven “component” scores including subjective sleep quality, sleep latency, sleep 
duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and 
daytime dysfunction. The sum of the seven component scores yields one global score, 
which is used to distinguish good and poor sleepers. Evidence of internal homogeneity, 
consistency (test-retest reliability), and validity have been demonstrated. 
 

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The Insomnia Severity Index (ISI) is a self-rated seven-item questionnaire which asks 
respondents to rate the nature and symptoms of their sleep problems using a Likert-type 
scale. The questions relate to subjective qualities of the respondent’s sleep, including the 
severity of symptoms, the respondent’s satisfaction with his or her sleep patterns, the 
degree to which insomnia interferes with daily functioning, how noticeable the 
respondent feels his or her insomnia is to others, and the overall level of distress created 
by the sleep problem. Respondents rate each question from 0 to 4, where higher scores 
indicate more severe symptoms of insomnia. A total score of 0–7 indicates “no clinically 
signiﬁcant insomnia,” 8–14 indicates “subthreshold insomnia,” 15–21 is “clinical 
insomnia (moderate severity),” and 22–28 indicates “clinical insomnia (severe).” Validity 
and test-retest reliability has been demonstrated.  
 
Measure of Mood Symptoms and Stress 
The Depression Anxiety Stress Scale (DASS-21) is a set of three self-report scales 
designed to measure the emotional states of depression, anxiety and stress. The 
Depression scale assesses dysphoria, hopelessness, devaluation of life, self-deprecation, 
lack of interest/involvement, anhedonia, and inertia. The Anxiety scale assesses 
autonomic arousal, skeletal muscle effects, situational anxiety, and subjective experience 
of anxious affect. The Stress scale is sensitive to levels of chronic non-specific arousal 
and assesses difficulty relaxing, nervous arousal, and being easily upset/agitated, 
irritable/over-reactive and impatient. Parents will be asked to use 4-point 
severity/frequency scales to rate the extent to which they have experienced each emotion 
state during the past week. Scores for Depression, Anxiety and Stress scales are 
calculated by summing the scores for the relevant items. High internal consistency and 
validity have been demonstrated. The Chinese version which we will use has been 
validated. 
 
The Parental Stress Scale (PSS) in Chinese is a self-report scale developed by Cheung 
(2000) based on the Parental Stress Scale developed by Berry and Jones (1995). It 
measures the level of stress experienced by parents, considering both positive and 
negative aspects of parenting. It contains 17 items representing pleasure or positive 
themes of parenthood (emotional benefits, self-enrichment, personal development) and 
negative components (demands on resources, opportunity costs and restrictions). 
Respondents are asked to agree or disagree with items in terms of their typical 
relationship with their child or children and to rate each item on a five-point scale: 
strongly disagree, disagree, undecided, agree, and strongly agree. The 8 positive items are 
reverse scored so that possible scores on the scale can range between 18-90. Higher 
scores on the scale indicate greater stress. The Parental Stress Scale demonstrated 

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satisfactory levels of internal reliability, and test-retest reliability. 
 
Measures of Quality of Life and Parental Competence 
The 12-item Short Form Health Survey (SF-12v2) is a locally validated measure of 
health-related quality of life (HRQOL) that has been shown to be valid, reliable and 
sensitive in Chinese adults and adolescents. It consists of 12 items that cover 8 subscales, 
namely physical functioning (PF), role physical (RP), bodily pain (BP), general health 
(GH), vitality (VT), social functioning (SF), role emotional (RE) and mental health (MH). 
The eight subscale scores can be aggregated into a physical component summary (PCS) 
score and a mental component summary (MCS) score. Each of the eight SF-12v2 
subscale has a scoring range from 0 to 100; a higher score indicates better HRQOL. The 
PCS and MCS scoring are norm-based with 50 and 10 being the Hong Kong general 
population mean and standard deviation, respectively. 
 
The Parenting Sense of Competence scale (PSOC) measures parental competence on two 
dimensions: Satisfaction and Efficacy. It is a 16 item Likert-scale questionnaire (on a 
6-point scale ranging from strongly agree [1] to strongly disagree [6]), with nine 
questions under Satisfaction and seven under Efficacy. Satisfaction section examines the 
parents’ anxiety, motivation and frustration, while the Efficacy section looks at the 
parents’ competence, capability levels, and problem-solving abilities in their parental 
role. 
 
Study Criteria 
Inclusion criteria: Parents/caregivers (aged 21 or above) of preschool children (aged 3 to 
6 years old) with a clinical diagnosis of ASD attending paediatric developmental clinic or 
clinical psychology service at the Duchess of Kent Child Assessment Centre (DKCAC) 
will be recruited. The clinical diagnosis of ASD would be made by either a Pediatrician 
or a Clinical Psychologist, using at least one of the following diagnostic tools: Childhood 
Autism Rating Scale, Second Edition (CARS-2), Autism Diagnostic Observation 
Schedule, Second Edition (ADOS-2), Autism Diagnostic Interview-Revised (ADI-R) and 
clinical interview based on diagnostic criteria of ASD depicted in the Diagnostic and 
Statistical Manual of Mental Disorders, Fifth Edition (DSM-5).  
 
Exclusion criteria: Parent/caregiver of children with diagnosed co-morbid neurological, 
psychiatric or medical conditions which could have affected their sleep, such as 
obstructive sleep apnea, epilepsy, childhood anxiety disorder will be excluded. 
 

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Statistics 
With a priori power analysis for multi-variate analysis of variance (MANOVA) with 
repeated measures, at an estimated effect size of 0.25, with projected power of 0.8 at the 
0.05 error level, the sample size required would be 66. For the current study, around 80 
subjects are planned to be recruited based on the estimated number of patients 
following-up at Duchess of Kent Child Assessment Centre (DKCAC), and the optimal 
sample size comparable with similar studies conducting RCT with an estimated attrition 
rate of 10%. Descriptive statistics will be calculated for parent and child characteristics. 
Categorical variables will be presented as observed frequencies and proportions. 
Correlational analyses, multivariate analyses of variance (within-subject, between group, 
mixed) will be conducted. All analyses will be conducted with .05 as level of statistical 
significance. 
 
Ethics 
The current study based on self-reporting questionnaires and commonly used assessment 
tasks that will pose no harm to the participating subjects. 
 
Data Handling and Record Keeping 
All the personal data will be handled and stored by the principal investigator in a safe 
database server under the participating institute. Paper questionnaires would be stored in a 
locked cabinet in the participating institute. The principal investigator, the co-investigators 
and supervisor are responsible for the personal data during and after the study. The data 
containing personal identifiers be kept for 10 years after publication of the first paper 
arising from the research project. Anonymized data be kept for 20 years after publication of 
the first paper arising from the research project. 
 
Financing and Insurance 
This is a non-funded project. 
 
Publication Policy 
After the analysis of the study findings we aim to have this original study written up in a 
paper for publication to share the result. 

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Appendix: Figure 1 
 
 
 

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References 
Allen, S. L., Howlett, M. D., Coulombe, J. A., & Corkum, P. (2016). ABCs of SLEEPING: a 
review of the evidence behind pediatric sleep practice recommendations. Sleep 
medicine reviews, 29, 1-14.  
Autism Speaks Autism Treatment Network, A.-A. (2019). Strategies to Improve Sleep in 
Children with Autism Spectrum Disorders - a Parent's Guide. Retrieved from 
https://www.autismspeaks.org/tool-kit/atnair-p-strategies-improve-sleep-childre
n-autism 
Beebe, D. W. (2006). Neurobehavioral morbidity associated with disordered breathing 
during sleep in children: a comprehensive review. Sleep, 29(9), 1115-1134.  
Berry, J. O., & Jones, W. H. (1995). The parental stress scale: Initial psychometric 
evidence. Journal of Social and Personal Relationships, 12(3), 463-472.  
Cheung, S.-K. (2000). Psychometric Properties of the Chinese Version of The Parental 
Stress Scale. Psychologia, 43, 253-261.  
Corkum, P., Davidson, F. D., Tan-MacNeill, K., & Weiss, S. K. (2014). Sleep in children with 
neurodevelopmental disorders: a focus on insomnia in children with ADHD and 
ASD. Sleep Medicine Clinics, 9(2), 149-168.  
Couturier, J. L., Speechley, K. N., Steele, M., Norman, R., Stringer, B., & Nicolson, R. 
(2005). Parental perception of sleep problems in children of normal intelligence 
with pervasive developmental disorders: prevalence, severity, and pattern. 
Journal of the American Academy of Child Adolescent Psychiatry, 44(8), 815-822.  
Doo, S., & Wing, Y. K. (2006). Sleep problems of children with pervasive developmental 
disorders: correlation with parental stress. Developmental medicine child 
neurology, 48(8), 650-655.  
Empowering Parents to Help Children Sleep Better: Parent-based Sleep Education for 
Children 
with 
Autism 
Spectrum 
Disorders. 
(2018). 
Retrieved 
from 
http://www.psychology.hku.hk/sleep/asd/index.html 
Krakowiak, P., Goodlin‐Jones, B., Hertz‐Picciotto, I., Croen, L. A., & Hansen, R. L. (2008). 
Sleep problems in children with autism spectrum disorders, developmental 
delays, and typical development: a population‐based study. Journal of sleep 
research, 17(2), 197-206.  
Kuhn, J. C., & Carter, A. S. (2006). Maternal self‐efficacy and associated parenting 
cognitions among mothers of children with autism. American Journal of 
Orthopsychiatry, 76(4), 564-575.  
Lo, M.-J. (2016). Relationship between Sleep Habits and Daytime Sleepiness, Inattention, 
and Aggressive Behavior among Taiwanese Kindergarten Children. Clinics Mother 
Child Health, 13(247), 2.  
Malow, B. A., Adkins, K. W., Reynolds, A., Weiss, S. K., Loh, A., Fawkes, D., . . . Clemons, T. 

3. Study Protocol_dated20200508,version2.doc 
12 
 
(2014). Parent-based sleep education for children with autism spectrum 
disorders. J Autism Dev Disord, 44(1), 216-228. doi:10.1007/s10803-013-1866-z 
Malow, B. A., Byars, K., Johnson, K., Weiss, S., Bernal, P., Goldman, S. E., . . . Glaze, D. G. 
(2012). A practice pathway for the identification, evaluation, and management of 
insomnia in children and adolescents with autism spectrum disorders. Pediatrics, 
130(Supplement 2), S106-S124.  
Meltzer, L. J., & Mindell, J. A. (2007). Relationship between child sleep disturbances and 
maternal sleep, mood, and parenting stress: a pilot study. Journal of Family 
Psychology, 21(1), 67.  
Mindell, J. A., Sadeh, A., Kohyama, J., & How, T. H. (2010). Parental behaviors and sleep 
outcomes in infants and toddlers: a cross-cultural comparison. Sleep medicine, 
11(4), 393-399.  
Ng, D. K., Kwok, K.-l., Cheung, J. M., Leung, S.-y., Chow, P.-y., Wong, W. H., . . . Ho, J. C. 
(2005). Prevalence of sleep problems in Hong Kong primary school children. 
Chest, 128(3), 1315-1323.  
Reid, G. J., Hong, R. Y., & Wade, T. (2009). The relation between common sleep problems 
and emotional and behavioral problems among 2‐and 3‐year‐olds in the context 
of known risk factors for psychopathology. Journal of sleep research, 18(1), 49-59.  
Richdale, A. L., & Schreck, K. A. (2009). Sleep problems in autism spectrum disorders: 
prevalence, nature, & possible biopsychosocial aetiologies. Sleep medicine 
reviews, 13(6), 403-411.  
Schneider, H. E., Lam, J. C., & Mahone, E. M. (2016). Sleep disturbance and 
neuropsychological function in young children with ADHD. Child neuropsychology, 
22(4), 493-506.  
Tso, W., Rao, N., Jiang, F., Li, A. M., Lee, S.-l., Ho, F. K.-w., . . . Ip, P. (2016). Sleep duration 
and school readiness of Chinese preschool children. The Journal of pediatrics, 169, 
266-271.  
Turnbull, K., Reid, G. J., & Morton, J. B. (2013). Behavioral Sleep Problems and their 
Potential Impact on Developing Executive Function in Children. Sleep, 36(7), 
1077-1084. doi:10.5665/sleep.2814 
Vriend, J., Corkum, P., Moon, E., & Smith, I. (2011). Behavioral interventions for sleep 
problems in children with autism spectrum disorders: current findings and future 
directions. J Pediatr Psychol, 36(9), 1017-1029. doi:10.1093/jpepsy/jsr044 
Yu, X., Lam, H., Au, C., Chan, S., Chan, D., & Li, A. (2015). Extended parent-based 
behavioural education improves sleep in children with autism spectrum disorder. 
Hong Kong J Ped, 20, 219-225.