{'fraction_non_alphanumeric': 0.04456094364351245, 'fraction_numerical': 0.02672720464332522, 'mean_word_length': 5.097317351598173, 'pattern_counts': {'":': 0, '<': 3, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
The associations of parental COVID‐19 related worries, lifestyles, and insomnia with child insomnia during the COVID‐19 outbreak

Abstract The impacts of the Coronavirus Disease 2019 (COVID‐19) pandemic on sleep health have been studied extensively. However, little is known about sleep problems within the family system during the pandemic. This study aimed to examine the influence of the COVID‐19 pandemic on insomnia in both adults and children, and to explore whether parental COVID‐19 related worries, lifestyles, and insomnia were associated with child insomnia. A total of 1355 parent–child dyads (39.2% fathers, mean age 38.37 years, SD = 5.34; 52.7% boys, mean age 12.47 years, SD = 1.67) were recruited from Jiangxi province in China from 4 to 18 February 2020. Data on insomnia, COVID‐19 related worries, physical activity, and screen time were collected using online questionnaires. Path analysis showed that COVID‐19 related worries and screen time were positively associated with insomnia in both parents and children; while children's physical activity was negatively related to children's insomnia. Parents' insomnia, COVID‐19 related worries, physical activity, and screen time were positively associated with children's insomnia, COVID‐19 related worries, physical activity, and screen time, respectively. Bootstrap tests showed that parents' worries were positively associated with children's insomnia via parents' insomnia and children's worries; parents' physical activity was negatively associated with children's insomnia via children's physical activity, parents' screen time was positively associated with children's insomnia via parents' insomnia and children's screen time. Both parental and child sleep are affected by the pandemic. Parental insomnia, stress reaction, and lifestyles contribute to child insomnia. Child sleep health may be maintained or improved by family bonds, home exercise, and sleep schedules.


| INTRODUCTION
The Coronavirus Disease 2019 (COVID-19) outbreak has a widespread and profound impact on daily routine, psychological distress, and physical health (Cao et al., 2020;Fisher et al., 2020;Pierce et al., 2020;Sanudo et al., 2020). Sleep, as a public health issue, is also impacted by the pandemic. Cross-sectional studies have revealed a high prevalence of insomnia among Chinese adults and adolescents (23.2%-29.9%) during the COVID-19 pandemic Zhou et al., 2020). A longitudinal study also reported that insomnia increased from 26.2% in pre-COVID-19 to 33.7% during early-COVID-19 periods (Li et al., 2020), although some studies reported opposite findings (e.g. longer night-time sleep duration, better sleep quality, and less daytime sleepiness) (Gao & Scullin, 2020;Ong et al., 2021). Previous studies have demonstrated that COVID-19 related stress, sociodemographic characteristics, environmental background, and biological factors were associated with sleep problems during the COVID-19 pandemic (Ong et al., 2021;Yu et al., 2020;Zhou et al., 2020). However, little is known about sleep problems within the family system during the pandemic.
To cope with COVID-19, restrictions and lockdown strategies were carried out. Schools were closed and non-essential public places were prohibited. People spent more time at home and contacted their families more often. Thus, parents and children may share similar sleep changes during this special period. The links between parents' sleep and children's sleep may be bidirectional. A cross-sectional study by Uccella et al. (2021) found that parents' discomfort related to quarantine (COVID-19 stress, sleep problems) was strongly associated with behavioural changes in their children (age under 18 years). Considering parents' roles in child development, parental factors might have greater effects on children's sleep. More studies are needed to examine whether parental factors, such as parental psychological distress, lifestyles, or insomnia, are associated with children's insomnia during the pandemic.
During the outbreak of COVID-19, parents and children stayed at home and faced various stressors together. Although children may experience increased stress and anxiety during the COVID-19 pandemic, parents too may experience poorer mental health given employment/financial circumstances, health concerns, and uncertainty (Fisher et al., 2020;Pierce et al., 2020). COVID-19 related stress (being worried about COVID-19, self-quarantine, and community infection) may be associated with increased parent anxiety, depression, and insomnia symptoms (Cao et al., 2020;Lu et al., 2020;Meyer et al., 2020). It is possible that children may become aware of their parents' worry about COVID-19 from direct discussion with their parents or by observing their behaviour. To date, no longitudinal studies have investigated the association between parents and children's COVID-19 related worries. However, one cross-sectional study also found positive associations between parents' and children's COVID-19 related fear (Suffren et al., 2021). These studies suggest that COVID-19 related worries could transfer from parents to children, and it is possible that these worries could affect sleep quality.
Home confinement also greatly changed people's lifestyles, especially for physical activity and screen time (Lopez-Bueno et al., 2020;Sanudo et al., 2020;Zheng et al., 2020). Because social isolation and physical distance restrictions were enacted, the usual exercise places were no longer accessible. Reduced physical activity levels and increased screen time have been reported (Meyer et al., 2020;Sanudo et al., 2020;Zheng et al., 2020). Insufficient physical activity is a key risk factor for physical health, mental well-being, cognition, and sleep (Biddle et al., 2019). With more time at home, people spend less time exercising, while spending more time watching TV, playing on computers, and using cell phones (Sanudo et al., 2020;Zheng et al., 2020). Limited physical activity and increased screen time during the COVID-19 pandemic negatively affected mental health and sleep quality (Lu et al., 2020;Meyer et al., 2020;Sanudo et al., 2020). Thus, it is essential to take physical activity and screen time into consideration with insomnia when it comes to the impact of the COVID-19 pandemic on sleep (Becker & Gregory, 2020).
Parental participation plays an important role in children's physical activity and screen time (Rhodes et al., 2020). One longitudinal study that collected three waves of data from 2007 to 2013 reported that parents' physical activity increased children's physical activity (Garriguet et al., 2017). Another longitudinal study that examined TV behaviours in parents and their girls at age 9 and 11 years, found that parents' TV-related behaviours increased girls' TV time (Davison et al., 2005). Furthermore, parental involvement may promote children's sleep through household practices and good sleep hygiene (Godsell & White, 2019;Mindell & Williamson, 2018). Also, a positive family environment, with less chaos and disorganisation could benefit children's sleep (Billows et al., 2009;Koopman-Verhoeff et al., 2019). Thus, those who have good family relationships and spend time with their parents may have good physical health, regular sufficient sleep, and good sleep quality. These findings suggested the positive role of parental lifestyles and sleep on child sleep. However, in the context of the COVID-19 pandemic, rare studies assess parents' sleep and children's sleep together, and physical activity levels and screen time simultaneously.
In this study, we aimed to examine: (1) How COVID-19 related worries and lifestyles influenced parents' and children's insomnia?
(3) Whether parental COVID-19 related worries, lifestyles, and insomnia were associated with children's insomnia? The first hypothesis was that parents and children with fewer COVID-19 related worries, more positive and regular lifestyles would show fewer insomnia symptoms during the COVID-19 pandemic. The second hypothesis was that parents who were more physically active, reporting less screen time, having fewer COVID-19 related worries and insomnia would have children who were also more physically active, reporting less screen time, having fewer COVID-19 related worries and insomnia. The third hypothesis was that children's insomnia might be associated with parents' insomnia, via COVID-19 related worries, physical activity, and screen time.

Participants and procedure
The cross-sectional data were collected online from 4 to 18 February 2020 after the outbreak of COVID-19 in China. Students above fourth grade and at least one of their parents from two schools in fear of infection), an online survey is a convenient and efficient method to assess participants' psychological distress and to obtain informed consent. Numerous studies have used a similar procedure to investigate the psychological impact of quarantine (Brooks et al., 2020).

Demographics
Demographic variables contained gender (male, female), age, location (urban, rural) and the highest level of education (primary school, junior middle school, high school, and college degree or above). Variables of location and education levels were only included in the parent's version questionnaire.

Physical activity
One item was used to measure parent and child physical activity level: "How many days per week did you exercise in the past two weeks?" Five different choices are given, each with a value of 1 to 5 (1 = null, 2 = <1 day per week, 3 = 1-2 days per week, 4 = 3-4 days per week, 5 = 5-7 days per week).

Screen time
Three items were used to assess parent and child screen time: (1) How many hours per day do you spend on TV? (2) How many hours per day do you spend on the computer? (3) How many hours per day do you spend on your cell phone? All questions were responded on a 4-point Likert scale (1 = <1 hour per day, 2 = 1-2 hours per day, 3 = 3-5 hours per day, 4 = ≥6 hours per day). The hours of screen viewing (TV, computer, and cell phone) were added up to obtain an overall screen time.

Self-quarantine
Parents were asked to indicate their current status (self-quarantine): Are you confirmed or suspected as having COVID-19? This item was rated from 1 to 5 (1 = confirmed, 2 = suspected, 3 = isolated in hospital, 4 = home isolation, 5 = normal people). Because category 1-4 had few responses, we recoded this item from 0 (no) to 1 (yes).

Community infection
Parents were also asked to indicate their current community infection status: Was anyone confirmed or suspected as having COVID-19 in your community or village? This item was rated from 1 to 3 (1 = confirmed, 2 = nobody, 3 = do not know).

Insomnia
To keep consistent with the assessment for children, the Youth Self-Rating Insomnia Scale (YSIS) was used to measure parents' and children's insomnia within the past 2 weeks (Liu et al., 2019). The YSIS consists of eight items that were based on ICSD-3 and DSM-5 diagnostic criteria. The eight items specifically are asking about sleep quality, sleep satisfaction, and sleep problems (difficulty initiating sleep, difficulty maintaining sleep, early morning awakening, sleep insufficiency, unrefreshing sleep, daytime functioning impairment). Each item is rated from 1 to 5. The total score ranges from 8 to 40. The cutoffs were as follows: normal (8-21), mild insomnia (22-25), moderate insomnia (26-29), and severe insomnia (30-48) (Liu et al., 2019). The YSIS has been used in Chinese community adults (Geng et al., 2021) and college students , demonstrating good reliability and validity. Besides, Cronbach's α was 0.88 with the current parent sample, and 0.89 with the children's sample, indicating good reliability.

Statistical analyses
Descriptive statistics were used to analyse sample characteristics, COVID-19 related worries, self-quarantine, community infection, the proportion of physical activity level, and the proportion of screen time. Pearson correlations between insomnia and all variables were examined. To examine our study hypotheses, path analysis was used to examine the relationships of physical activity, screen time, COVID-19 related worries, self-quarantine, and community infection among parents and children. Demographics were modelled as covariates; indirect effects were calculated with bootstrapping. Regarding COVID-19 related worries, 36 participants did not report their worries because they indicated that their family members or community had been infected with COVID-19. Two methods have been used to deal with these participants. First, they were grouped into the "very worried" category given the higher stress they might meet. Second, they were regarded as missing data. The results of the two methods are similar. The findings of the first method are presented in the results section, and the main findings of the second method are supplied, see Figure S1. The fit of model without an interaction term was evaluated by chisquare (χ 2 ), the comparative fit index (CFI), the Tucker-Lewis index (TLI), and the root mean square error of approximation (RMSEA). Values of CFI and TLI above 0.09, and RMSEA values below 0.08 are an acceptable model fit (Hu & Bentler, 1999). Multiple group contrasts were conducted to examine differences in the effects of parents' lifestyles and well-being on their children between different demographics, including parents' sex, children's sex, children's age, and parent-child relationships (father-boy, father-girl, mother-boy, and mother-girl). Changes of χ 2 were used to test significance. Statistical analyses were conducted with SPSS 26.0 and Mplus 7.0. The significant level was set at p < 0.05, two tails.

RESULTS
Descriptive statistics of demographics, COVID-19 related worries, physical activity, and screen time The demographics, COVID-19 related worries, self-quarantine, and community infection are presented in Table 1 The Pearson correlation matrix of study variables

Path analysis
The best fitting model and its standardised path coefficients are shown in Figure 1.   The prevalence of insomnia in the current study is lower than that reported by using the Insomnia Severity Index (Li et al., 2020) and also lower than that reported by the YSIS scale in a community sample before the pandemic (Geng et al., 2021). However, the figure aligns with the findings of a study conducted among college students, which showed a similar proportion (6.1%) of clinical insomnia through for the YSIS scale . This may be attributed to the special data collection period and the resilience of individuals. The data were Recent studies have also found improved sleep (Blume et al., 2020;Wright et al., 2020). These findings indicated that the general public may remain resilient and flexible in school/work schedules and preserve/enhance sleep health (Becker & Gregory, 2020;Gao & Scullin, 2020). Finally, another possible reason may be that the participants were mostly from rural areas. Families could be more protected by the fact of being able to stay in the open air, and through the confinement due to the lower possibility of being infected.
Consistent with previous studies (Suffren et al., 2021), our findings showed that parents' COVID-19 related worries were significantly related to children's COVID-19 related worries. One study has indicated that COVID-19 related worries was one of important risk factors for insomnia (Lu et al., 2020). Extending this study, we found associations of parental COVID-19 related worries and insomnia with children's insomnia. Parents' COVID-19 related worries could be indirectly associated with increased children's insomnia via parents' insomnia and children's COVID-19 related worries. One study has revealed that parents' reported COVID-19 fear was more affected by contextual concerns (e.g., financial resources and health services) than their children (Suffren et al., 2021). Thus, parents may convey their concerns about the epidemic to children through communication/ behaviours, which would affect children's cognition of the pandemic, and lead to poor sleep.
Similar to previous studies, we found that parents and children's insomnia were positively associated with screen time (Lopez-Bueno et al., 2020;Suffren et al., 2021;Zheng et al., 2020), while children's physical activity was specifically related to children's insomnia. Contrary to the expectation that physical activity would be significantly associated with insomnia (Lu et al., 2020), we did not find support in our parent sample. One reason for such insignificance might be that parents spent less time exercising, and more time watching TV, playing on the computer or using cell phones; thus, the effect of physical activity on sleep was decreased. This also accords with a previous study , which showed that people stay at home, spend less time exercising, and more time sitting, and expose themselves to more artificial light or digital screens with excessive use of TV, cell phone, and computer. In general, increased screen time and less physical activity may have adverse effects on sleep quality (Sanudo et al., 2020).
This current study confirmed that children's physical activity and screen time were positively associated with parents' physical activity and screen time (Garriguet et al., 2017). Importantly, findings showed that parents' lifestyles and insomnia could be indirectly associated with children's insomnia: (1) parents' physical activity was indirectly associated with children's insomnia via children's physical activity; (2) parents' screen time was indirectly associated with children's insomnia via parents' insomnia and children's screen time. These results could be explained in different ways. Sleep behaviour is associated with strong familial aggregation, as well as some genetic transmission (Dauvilliers et al., 2005;Partinen et al., 1983). Family studies also confirmed the effects of genetic factors on insomnia (Watson et al., 2006). Moreover, one study pointed out that adolescents' insomnia was significantly associated with parental insomnia symptoms in China (Liu et al., 2016). Nevertheless, it also suggested that adolescents' sleep may largely be affected by biological and environmental factors (Liu et al., 2016). During the COVID-19 crisis, environmental factors could be parental involvement (e.g., parenting, parents' modelling role and parent-child relationship) (Garriguet et al., 2017;Rhodes et al., 2020). Typically, children spend most of their time with their parents during the COVID-19 pandemic. Children may imitate their parents' behaviours, such as parents' exercise habits, and digital habits. It should also be noted that links of COVID-19 related worries, lifestyles, and sleep between parents and children may be bidirectional (Sleddens et al., 2017). To date, only one cross-sectional family study reported that parents with children under 6 years were more likely to be affected by the COVID-19 pandemic (Uccella et al., 2021).
Thus, longitudinal analysis is needed to examine possible bidirectional associations.
These findings have potential implications for parental involvement and sleep during the pandemic. Solutions to promote good sleep are to keep a regular and healthy sleep schedule, exercise regularly, use fewer electronic devices before sleep, and pay less attention to the COVID-19 pandemic that would rouse anxiety. Owing to the independent impact of COVID-19 related worries, physical activity, screen time, and the indirect impact of parental involvement, it is expected that increasing physical activity, limiting screen time, and COVID-19 related worries concurrently with parental involvement would be a better protective factor to improve child sleep than only focusing on physical activity or others. Moreover, these results can be used to guide physical and psychological measures to prevent insomnia of parents and children.
This current study has its strengths and limitations. Although a large sample of parent-child dyads assessed by the same questionnaire is a strength, several limitations should be noted. First, this study is cross-sectional, so the causal effect cannot be determined. Second, the findings of this study were derived from participants that were mostly from rural areas. Furthermore, children under 9 years and their parents were not recruited, as children were required to finish the self-report questionnaire. However, several studies indicate that parents who have young children reported more behavioural and emotional problems than those with older ones during the COVID-19 outbreak Uccella et al., 2021). Third, this study was

ACKNOWLEDGMENTS
The present study was funded by National Natural Science Foundation of China (grant numbers: 31700987). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

CONFLICT OF INTEREST
None.

AUTHOR CONTRIBUTIONS
Nalan Zhan collected and analysed the data and drafted the manuscript; Yeqing Zhang collected the data and revised the manuscript; Dongjie Xie revised the manuscript; Fulei Geng designed the study, supervised the collection and analyses of data, and revised the manuscript.

DATA AVAILABILITY STATEMENT
The dataset and Mplus code are available on request from the corresponding author, Fulei Geng.