A Longitudinal Study of Parental Sleep Intervention for Behavioral Insomnia in Early Childhood

Sleep efficiency is defined as the percentage of total sleep time (sleep period determined by the actigraphy) to the total time spent in bed (from the time children go to bed to the time they finally get up in the morning). A higher percentage reflects more continuous and higher-quality sleep. As SE is closely related to SOL and nighttime awakings, it is selected as the primary outcome of the current study.Through the built-in accelerometer and other sensors, the actigraphy can be used to monitor an individual's activity level and sleep situation, thereby analysing the child's sleep patterns such as sleep efficiency. The team technician will export the relevant sleep indicators recorded by the actigraphy and calculate relevant outcome measures. Moreover, the actigraphy is validated with parental records of sleep diaries.

In this study, SOL serves as the indicator of sleep initiation difficulty, with a threshold exceeding 20 minutes indicating prolonged sleep onset. Improvement in SOL (i.e., shortened latency) following the intervention will suggest enhanced self-regulation capacity and reduced reliance on parental assistance at bedtime. Moreover, the actigraphy is validated with parental records of sleep diaries.

Wake after sleep onset (WASO) is defined as the total duration of wakefulness between initial sleep onset and final morning awakening. Longer WASO indicates poorer nighttime sleep quality. Improvements (reductions) following intervention indicate better sleep consolidation. Moreover, the actigraphy is validated with parental records of sleep diaries.

The number of nighttime awakenings (NW) refers to the total number of awakening events lasting more than 5 minutes per night. A frequency of two or more awakenings per night may indicate poor nighttime sleep quality. This indicator will be reported to assess the degree of fragmentation of nighttime sleep. Improvements (reductions) following intervention indicate better sleep consolidation. Moreover, the actigraphy is validated with parental records of sleep diaries.

BISQ is a parent-reported instrument designed to screen for sleep problems in infants and toddlers. This study will use the standardised Chinese version, which covers multiple aspects of early childhood sleep, including sleep onset conditions, total sleep duration, nighttime awakenings, co-sleeping, and overall sleep patterns.

ISAS and TSAS were developed and validated by the Provincial Research Working Group of Chinese Infant and Toddler Sleep Assessment Scale for children aged 4-11 months and 12-35 months, respectively. Total scores, derived from all items, reflect sleep quality, with responses rated on a four-point Likert scale of 1 to 4. Higher scores indicate poorer sleep quality.

The ASQ:SE-2 is an internationally recognised developmental screening tool for assessing social-emotional development in children aged 1 to 72 months.

The questionnaire assesses a child's development across 7 specific behavioural dimensions:

• Self-Regulation: ability to calm or settle themselves.
• Compliance: ability to follow rules and respond to limits.
• Social-Communication: use of gestures, sounds, and words to interact with others.
• Adaptive Functioning: ability to manage daily routines like eating, sleeping, and toileting.
• Autonomy: ability to act independently and demonstrate self-confidence.
• Affect: expression of feelings and emotions.
• Interpersonal interaction: ability to engage with parents, other adults and children.

A higher score indicates more concerning behaviours.

Maternal daytime sleepiness will be assessed using the Epworth Sleepiness Scale (ESS), an 8-item self-reported questionnaire employing a 4-point Likert scale of 0 to 3. It measures how likely a person is to doze off or fall asleep in 8 common, sedentary situations of daily life. Higher scores indicate greater daytime sleepiness, with a score of 10 or above indicating excessive daytime sleepiness.

Maternal mental health will be assessed using the World Health Organization Five Well-Being Index (WHO-5), a 5-item self-reported questionnaire employing a 6-point Likert scale of 0 to 5. These items reflect positive mood, vitality, and general interests over the preceding 14 days. Higher scores indicate greater well-being.

Maternal parenting stress will be assessed using the Parenting Stress Index-Short Form (PSI-SF), a 36-item parent-reported questionnaire consisting of three subscales including parental distress, parent-child dysfunctional interaction, and difficult child. The total score ranges from 36 to 180. A score of 85 or less indicates a normal level of parental stress. A score between 86 and 90 represents a critically high level. A score greater than 90 suggests a high level of parental stress, and a score of 99 or above indicates an extremely high level of parental stress.

Maternal occupational stress will be assessed using the short version of the Copenhagen Psychosocial Questionnaire (COPSOQ), a 44-item self-reported questionnaire consisting of eight subscales. Higher scores in the job demands and job insecurity subscales reflect greater occupational stress, whereas higher scores in the personal impact and development, interpersonal relationships and leadership, and job satisfaction subscales indicate lower levels of occupational stress.

Maternal life satisfaction will be assessed using the Satisfaction With Life Scale (SWLS), a 5-item self-reported questionnaire employing a 7-point Likert scale of 1 to 7. Higher scores indicate greater perceived life satisfaction.

Mother-child bonding will be assessed using the Postpartum Bonding Questionnaire (PBQ), a 25-item self-reported questionnaire employing a 6-point Likert scale of 0 to 5. Higher scores indicate greater impairment in the mother-child relationship.

Maternal satisfaction with family functioning will be assessed using the Family APGAR Index (APGAR), a 5-item self-reported questionnaire employing a 3-point Likert scale of 0 to 2. Scores range from 0 to 10, with higher scores indicating better family functioning (0-3 = highly dysfunctional, 4-6 = moderately dysfunctional, 7-10 = highly functional).

Child temperament will be assessed using age-appropriate version of scales, including the Revised Infant Temperament Questionnaire (RITQ) for infants aged 5 to 11 months, and the Toddler Temperament Scale (TTS) for children aged 1 to 3 years. Both questionnaires assess nine subscales: rhythmicity, adaptability, approach, intensity, mood, activity, threshold, distractibility, and persistence.

Child neurodevelopment will be assessed using the Chinese Developmental Scale for Children Aged 0-6 Years (2nd Edition) (CDSC-II). This scale evaluates five subscales: gross motor, fine motor, adaptive ability, language, and social behaviour, comprising a total of 261 items across 28 age-in-months groups. The development quotient will be used to determine subscale-specific and overall development status, with lower scores signifying developmental vulnerability.