Sleep Patterns among South Korean Infants and Toddlers: Global Comparison

To sleep or to breastfeed: Associations between feeding method and sleep in infants and children

AIM

This study aimed to understand the association between feeding method, specifically breastfeeding versus non-breastfeeding, at 6 and 12 months and infant sleep over the first 3 years of life.

METHODS

A sample of 444 mother-infant dyads from the Maternal Adversity, Vulnerability and Neurodevelopment cohort were analysed. Based on retrospective maternal reports between 3-24 months, infants' breastfeeding status was determined at 6 and 12 months. Nocturnal sleep duration, longest period of consecutive sleep, and total sleep over 24 h were measured by maternal reports at 6, 12, 24 and 36 months.

RESULTS

Generalized Estimating Equations revealed no significant association between feeding status, both at 6 and 12 months, and nocturnal sleep duration or total sleep over 24 h between 6-36 months (p > 0.05). However, breastfeeding at both 6 and 12 months was associated with shorter periods of consecutive sleep, at 6 and 12 months (p < 0.05) but not at 24 and 36 months (p > 0.05).

CONCLUSION

Our findings suggest that breastfeeding seems to be associated with more infant sleep fragmentation but not with total sleep duration in early infancy. However, this sleep fragmentation does not persist into later infancy and early toddlerhood.

Cross-country comparison of parental reports and objective measures of sleep patterns of typically developing children and autistic children between the UK and South Korea

Sleep duration and disturbances in typically developing (TD) children have been found to vary across countries. Given the impact of culture on sleep patterns in TD children, it is also necessary to examine the impact of culture on sleep patterns in children with atypical development. However, previous studies have often relied only on parent reports of children's sleep. Hence, the present study conducted a cross-cultural comparison of sleep duration and disturbances of school-aged TD children and autistic children in the UK and South Korea (hereafter Korea) using both subjective and objective sleep measurements. Cultural differences were observed in both actigraphy measures and parent reports of children's sleep duration and disturbances. Both TD children and autistic children in Korea had a later bedtime, later getting up time and shorter nocturnal sleep duration than their peers in the UK (p < .05). Furthermore, greater parent-reported sleep disturbances were reported in TD children in Korea compared to TD children in the UK and in autistic children in the UK compared to autistic children in Korea. Correlational analyses indicated that most parent-reported measures of children's sleep did not significantly correlate with objective measures and child reports, suggesting that studies on children's sleep can benefit by collecting data from multiple sources. Taken together, these findings suggest a cultural influence on sleep duration and disturbances of both TD children and autistic children. This study raises questions for further research to identify factors underlying cultural differences in children's sleep duration and disturbances.

Padrão de sono em crianças de 12 a 36 meses de idade

Resumo Objetivo Avaliar o padrão de sono de crianças de 12 a 36 meses. Método Estudo transversal, realizado em uma amostra de 808 crianças com 12–36 meses de idade, que frequentavam creches no distrito de Viseu, Portugal. Coleta de dados realizada por meio de questionário aplicado aos pais, entre novembro de 2018 e setembro de 2019. Estudo aprovado pela comissão de ética do Instituto de Ciências Biomédicas Abel Salazar, Portugal. Resultados Verificou-se que durante a semana as crianças dormiam, por dia, entre 9h 30m e 18h (M=12h 25m ±1h 02m) e no fim de semana, entre 9h e 19h (M=12h 49m ±1h 15m). No fim de semana, as crianças deitavam-se e acordavam mais tarde que à semana (M=21h 42m ±40m, M=8h 15m ±50m, respetivamente). A maioria não dormia a sesta da manhã, somente a da tarde. Conclusão Os resultados indicam que a maioria das crianças (91,5% semana; 85,6% fim de semana) dorme o número de horas recomendado. As mais novas são as que dormem mais. Implicações para a prática É importante que, nas consultas de vigilância de saúde, os enfermeiros realizem educação para a saúde direcionada aos pais sobre a relevância de manter um padrão de sono adequado à criança.

A qualitative study of the sleep ecology of infants under 2 years old and their mothers in South Korea

OBJECTIVES/DESIGN

Infancy is a crucial period for establishing an individual's sleep pattern, and it is a common period during which infants and mothers experience sleep problems. The aim of this qualitative study was to explore the sleep ecology of infants under 2 years of age and their mothers.

SETTING/PARTICIPANTS

The study participants were 20 mothers with infants aged 3-19 months living in South Korea.

METHODS

Data were collected through in-depth interviews and analyzed using the thematic analysis.

RESULTS

Five themes related to the sleep of infants and their mothers emerged from the data: (1) changes in sleep patterns, (2) room-sharing, (3) environmental factors affecting sleep, (4) efforts to improve sleep quality, and (5) infant sleep and the mother's health. The sleep patterns of infants and their mothers were mutually interrelated, and were strongly affected by various environmental factors, including infants' biological maturity (a microsystem) as well as cultural factors (a macrosystem). Culture had an especially profound effect on sleep patterns of infants, similar to the effects of microsystem-level factors.

CONCLUSIONS

To improve the sleep quality of infants and mothers, an ecological approach considering the biological characteristics and cultural contexts of infants is required based on an understanding of sleep as a phenomenon that evolves in a relationship of mutual influence between infants and mothers.

A Quantile Regression Analysis of Factors Associated with First-Time Maternal Fatigue in Korea

The aim of this cross-sectional study was to identify the factors associated with different percentiles of first-time maternal fatigue. A total of 123 first-time healthy mothers aged 18 years or older participated through an online survey. The fatigue was measured by the Korean version of the fatigue severity scale. Main variables were constructed based on the integrated fatigue model, which included mothers' sleep quality, parenting stress, the amount of free time mothers have, the number of the child's night wakings, general characteristics including socioeconomic status, and working status. Quantile regression was used to analyze the associated factors according to the fatigue level of first-time mothers with a young child. The mean age of the mothers and children were 32.11 years and 20.81 months, respectively. Mean fatigue score was 6.16 among the 75% quantile with high fatigue score. Lack of adequate free time in mothers, advanced maternal age, being a housewife, having a moderate income, and frequent night wakings of their child significantly increased fatigue among mothers in the third quantile of fatigue. To reduce fatigue, healthcare providers should focus on exploring ways to reduce maternal sleep disturbance and improve maternal sleep quality.

Correlates of Sleep Duration in Early Childhood: A Systematic Review

OBJECTIVE

This systematic review aimed to summarize correlates of sleep duration in children under 5 years of age.

METHODS

Six electronic databases (PubMed, PsycINFO, MEDLINE, CINAHL, SPORTDiscus, and Scopus) were searched from inception to May 2019. Observational studies and intervention studies reporting cross-sectional results from baseline data were considered. Data were extracted using a predesigned form and potential correlates were categorized following a sociological framework.

RESULTS

One-hundred and sixteen studies, representing 329,166 children, met the inclusion criteria, with a high risk of bias in 62 included studies. A total of 83 correlates of sleep duration were identified. Among the associations studied four or more times, correlates of nap duration were child's age and nighttime sleep onset/bedtime; correlates of nighttime sleep duration were household income, parent marital status, parental adiposity level, nighttime sleep duration at younger age, nighttime sleep onset/bedtime, nighttime sleep wakeup time, and frequency of current bedtime routine; correlate of total sleep duration was screen time.

CONCLUSIONS

Young children from low-income households, single families, or having overweight parents may be at risk for short sleep duration. Promoting healthy sleep duration from an early age appears essential. Effective practices may include encouraging an earlier bedtime, limiting screen time, and establishing a regular bedtime routine. The absence of consistent evidence in the psychological, cognitive, and emotional domain as well as the physical environmental domain warrants further research.

How do infants and toddlers sleep in Spain? A cross-sectional study

There is limited information on sleep patterns among infants and toddlers in Spain. The aim of this study was to assess sleep patterns in children three to 36 months of age in Spain. A cross-sectional study was conducted between February 2017 and February 2018. Sociodemographic data and sleep variables were collected using an expanded version of the validated Spanish version of the brief infant sleep questionnaire. A total of 1,404 parental reports on children (725 males; 679 females) with a mean age of 18.8 ± 9.5 months were collected. Parents who perceived their child's sleep as problematic (39% of our sample) reported fewer sleep hours (median 9 versus 10 h), more night awakenings (median 2 versus 1), and longer periods of nocturnal awakenings (median 0.5 versus 0.08 min) (p < 0.001). Parental presence at the time of sleep onset and later and irregular bedtime routines were significantly associated with a reduction in total sleep time, longer sleep latency, and disruptive night awakenings (p < 0.001). These findings highlight the need for further studies to assess how to improve sleep patterns as a relevant modifiable lifestyle factor.Conclusion: A substantial percentage of the population perceived that their children slept poorly, which was evident in a variety of sleep patterns, including sleep duration and sleep quality. What is known: • Previous research has established that sleep difficulties among pediatric population affect up to 30% of all children and up to 20-30% of infants and toddlers. • A positive relationship between less parental bedtime involvement and sleep consolidation in infants and toddlers has been established. What is new: • More than a third of Spanish parents perceived their infants and toddlers sleep as problematic and their children reportedly have shorter night sleep hours, more night awakenings, and longer periods of nocturnal awakenings. • Later and irregular parental bedtime routines were associated with worst infants and toddlers sleep.

Behavioral insomnia in infants and young children

In infants and young children, bedtime problems and night waking are common and the main presentations of insomnia. Poor sleep may critically impact the daytime functioning and mood of the child and their caregivers. A comprehensive sleep history, a sleep diary/log, and the BEARS (Bedtime problems, Excessive daytime sleepiness, Awakenings during the night, Regularity and duration of sleep, and Sleep-disordered breathing) sleep screen are useful for diagnosing sleep problems in young children. Behavioral therapies for this type of insomnia include extinction, bedtime fading with positive routines, and scheduled awakening. Previous studies of behavioral interventions for young children showed significant improvements in sleep-onset latency, night waking frequency, and night waking duration. Parent education about their child's sleep, bedtime routines, and sleep hygiene is essential for treatment.

A Systematic Review on Cross-Cultural Comparative Studies of Sleep in Young Populations: The Roles of Cultural Factors

Recent studies have shown that sleep is influenced and shaped by cultural factors, including cultural values, beliefs and practices. However, a systematic understanding of how cultural factors in countries may influence sleep duration and sleep disturbances is still lacking. Therefore, we focused on a comparison of sleep duration and disturbances in young populations between countries. We report cross-cultural differences between the child, parent and environmental factors, and their association with sleep duration and disturbances. The review is based on literature searches of seven databases published until December 2020. Studies were included if they investigated sleep duration and disturbances of individuals up to 18 years across at least two or more countries. The results of this review have shown that sleep duration and disturbances vary between countries and regions and certain factors (e.g., bedtime routines, sleeping arrangement, physical activity and psychological functioning) have been associated with sleep duration or disturbances. This review also demonstrates that certain factors which were associated with sleep duration or disturbances in one country, were not shown in other countries, suggesting a need for recommendations for age-related sleep duration and sleep interventions to consider cultural differences that influence sleep duration or disturbances in individual countries or regions.

Environmental Scan of Sleep Health in Early Childhood Programs

OBJECTIVE

To ascertain how sleep health knowledge is translated to early care and education (ECE) programs, using a multi-component environmental scan.

METHODS

A website scan identified organizations' sleep content re: recommended practices, developmental effects, and "actionable" ratings (0-2). ECE staff surveys assessed preparedness, practices, and beliefs about addressing sleep health and sleep problems in ECE programs. Semi-structured interviews with stakeholders from the ECE, pediatric and sleep communities assessed awareness, priorities, and practices at their organizations.

RESULTS

Of 15 websites scanned, half lacked sleep content on links to development, optimal duration, or scientific background. ECE staff (n = 31) were comfortable speaking to parents about healthy sleep, and with incorporating sleep education and guidance into ECE. Stakeholders (n = 15) rated healthy sleep as a high relevance, but lower priority issue. Within ECE settings stakeholders reported that knowledge about specific links to health and development was poor and that sleep health was often obscured by "safe sleep" issues. Their recommendations included: linking sleep health to "hot topics" such as obesity or preschool suspensions and expulsions, integrating it with the teaching of routines, and raising public awareness.

CONCLUSION

Despite understanding that healthy sleep promotes school readiness, there is insufficiently specific, actionable information in ECE training, programs, or policies. Findings suggest a need for an awareness campaign with clear, actionable messaging, dissemination of turnkey materials, and integration with policy and professional training systems.

TRIAL REGISTRATION

- ClinicalTrials.Gov: NCT03556462.

Associations of screen time, sedentary time and physical activity with sleep in under 5s: A systematic review and meta-analysis

Sleep is crucial to children's health and development. Reduced physical activity and increased screen time adversely impact older children's sleep, but little is known about these associations in children under 5 y. This systematic review examined the association between screen time/movement behaviors (sedentary behavior, physical activity) and sleep outcomes in infants (0-1 y); toddlers (1-2 y); and preschoolers (3-4 y). Evidence was selected according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and synthesized using vote counting based on the direction of association. Quality assessment and a Grading of Recommendations, Assessment, Development and Evaluation was performed, stratified according to child age, exposure and outcome measure. Thirty-one papers were included. Results indicate that screen time is associated with poorer sleep outcomes in infants, toddlers and preschoolers. Meta-analysis confirmed these unfavorable associations in infants and toddlers but not preschoolers. For movement behaviors results were mixed, though physical activity and outdoor play in particular were favorably associated with most sleep outcomes in toddlers and preschoolers. Overall, quality of evidence was very low, with strongest evidence for daily/evening screen time use in toddlers and preschoolers. Although high-quality experimental evidence is required, our findings should prompt parents, clinicians and educators to encourage sleep-promoting behaviors (e.g., less evening screen time) in the under 5s.

What does sleep hygiene have to offer children's sleep problems?

Sleep hygiene practices have been described extensively in the literature. There is considerably less clarity about relationships between particular elements of sleep hygiene and particular sleep outcomes, and which intervention approaches using sleep hygiene principles are effective. In this review, we describe themes extracted from a systematic review of the sleep hygiene literature. We systematically searched Psycinfo, CINAHL, Cochrane, Ovid Medline, Embase, and Web of Science Search Engines up to August, 2017. We included all studies that associated sleep hygiene (behaviors adjacent to bedtime and during the night) with sleep duration and/or sleep onset latency and/or night waking or that used sleep-hygiene based interventions to improve sleep duration and/or sleep onset latency and/or night waking (n = 44). We organized our findings into themes by age group, sleep hygiene factors, and interventions. We provide evidence-based recommendations about areas of sleep hygiene that have significant empirical support and those that require urgent attention.

Levels and correlates of 24-hour movement behaviors among South Koreans: Results from the Korea National Health and Nutrition Examination Surveys, 2014 and 2015

PURPOSE

This study aimed to examine the levels and correlates of 24-h movement behaviors (i.e., physical activity, sedentary time, and sleep), and different patterns of these behaviors in a nationally representative sample of South Koreans aged 12 years and older. This study also aimed to examine the sociodemographic correlates of 24-h movement behaviors stratified by age groups.

METHODS

Self-reported, repeated cross-sectional data from 10,708 participants in the 2014 and 2015 Korea National Health and Nutrition Examination surveys were used. Key variables included moderate-to-vigorous intensity physical activity, muscular strengthening exercises, walking, active transportation, sedentary time, and sleep. Sociodemographic variables included age, sex, household income, area of residence, and education level. Descriptive statistics by sex and age as well as general linear models by age group were performed.

RESULTS

The proportions of individuals meeting the moderate-to-vigorous intensity physical activity, muscular strengthening exercises, and sleep guidelines were, respectively, 21.6%, 22.1%, and 32.5% in male youth; 6.9%, 4.5%, and 22.8% in female youth; 55.5%, 30.8%, and 54.0% in male adults; 48.8%, 14.4%, and 57.6% in female adults; 44.0%, 30.6%, and 45.5% in male older adults; and 29.5%, 8.9%, and 37.3% in female older adults. The proportions of individuals showing the most ideal combinations of 24-h movement behaviors were only 3.2% in youth, 0.4% in adults, and 0 in older adults. Universally, older age, female sex, or living in metro Seoul were associated with unfavorable patterns of 24-h movement behaviors across different age groups. However, the associations of income and education with movement behaviors were mixed across age groups.

CONCLUSION

Overall, the proportion of South Koreans with a healthy 24-h movement behavior pattern is low. The sociodemographic correlates of different types of 24-h movement behaviors should be considered when designing targeted interventions for the promotion of healthy active living for South Koreans.

Screen viewing behavior and sleep duration among children aged 2 and below

Background

Few studies have investigated the association between screen viewing (SV) and sleep duration among young children. This study aims to examine the association between total and device-specific SV and sleep duration among children aged 2 and below.

Methods

We conducted a cross-sectional study of 714 Singaporean children aged 2 years and below. Parents were recruited during routine well-child clinic visits from two national polyclinics. In Singapore, all parents visit well-child clinics with their children at regular intervals for routine check-ups and vaccinations. Socio-demographic characteristics, duration of total and device-specific SV, and sleep duration were reported by parents via interviewer-administered questionnaires. Multiple linear regression analysis was used to assess associations between various types of SV and sleep duration, adjusted for socio-demographic variables. Due to significant interaction between SV and age, stratified analyses for children aged less than 6 months and those aged 7–24 months were performed.

Results

The prevalence of daily SV among children was 53.1%; 28.3% in children up to 6 months and 73.8% in children aged 7 to 24 months. TV viewing was reported for 44.3% of all children and mobile device SV for 30.1%. Children’s average sleep duration was 13.9 (SD = 3.5) hours daily and younger children had longer sleep duration than older ones (up to 6 months: mean = 15.6 h, SD = 3.9; 7–24 months: mean = 12.4 h, SD = 2.2; P < 0.01). In the regression analysis among all children, each 1 h per day increment in total SV was significantly associated with 0.26 h shorter sleep duration with similar significant associations for TV (β = − 0.28 h, 95%CI: -0.50, − 0.06) and mobile devices (β = − 0.35 h, 95%CI: -0.61, − 0.09). Stratified analysis revealed significantly greater reductions in sleep with higher SV among children aged 6 months and below (β = − 0.73 h, 95%CI: -1.12, − 0.34), while associations were weaker in older children (β = − 0.13 h, 95% CI: -0.24, − 0.01).

Conclusions

This study provides evidence for a substantial association between longer SV and shorter sleep duration among very young children. These associations appeared stronger among children aged 6 months and below as compared with those aged 7 to 24 months. Further studies are warranted to confirm our findings.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-6385-6) contains supplementary material, which is available to authorized users.

[Adaptation and study of the measurement properties of a sleep questionnaire for infants and pre-school children]

INTRODUCTION

Although sleep disturbances in infants and toddlers are common, there is no suitable validated tool in Spanish to evaluate sleep disorders. The Brief Infant Sleep Questionnaire (BISQ) is a well-established multidimensional questionnaire widely used internationally.

OBJECTIVES

To adapt the BISQ questionnaire to Spanish and analyse its reliability and validity. To explore its feasibility, both in the clinical context, and in epidemiological research.

METHODS

Participants were parents of children between 3 and 30 months of age. The adaptation to Spanish (BISQ-E) was achieved by using both back translation and consensus, following the international guidelines.Reliability was determined by means of test-retest and measurement of agreement (Kappa value) between 2forms of administration of the questionnaire (self-administration and clinical interview). Construct validity was established by analysing its correlation with a sleep diary.

RESULTS

A total of 87 families/children participated. The test-retest reliability undertaken in 60 subjects was excellent; r = 0.848 (P<0.001). The kappa value was 0.939 (95% CI: 0.858-1.00, P<0.001).The agreement between BISQ-E and the sleep diary was analysed in 27 families/children, with statistically significant values being obtained for the following variables: bedtime (r = 0.731), hours of night sleep (r = 0.726), hours of daytime sleep (r = 0.867), and number of nocturnal awakenings (r = 0.888) (P < 0.001).

CONCLUSIONS

The Spanish adaptation of the BISQ shows overall adequate validity and reliability for the evaluation of sleep in infants and pre-school children. Its use as a clinical tool, or for clinical-epidemiological research studies, is feasible.