|
|
 |
|
ORIGINAL ARTICLE |
|
Year : 2022 | Volume
: 19
| Issue : 4 | Page : 234-240 |
|
Association between screen time and psychosocial and behavioral well-being of preschoolers during the COVID-19 lockdown in Tamil Nadu
Anuradha Gunasekaran1, Viswanathan Rangaswamy Gounder Karupannagounder2, Muraleetharan Gopal2, Panneerselvam Periasamy3, Suganthi Vajiravelu4, Sasikala Gunasekaran5
1 Aster Clinics, Dubai, UAE 2 Department of Pediatrics, Government Erode Medical College and Hospital, Erode, Tamil Nadu, India 3 Department of Physiology, Government Erode Medical College, Erode, Tamil Nadu, India 4 Department of Physiology, Vinayaka Mission's Kirupananda Variyar Medical College and Hospital, VMRF (D.U.), Salem, Tamil Nadu, India 5 Department of Nursing, Government Erode Medical College and Hospital, Erode, Tamil Nadu, India
Date of Submission | 09-Jul-2022 |
Date of Decision | 23-Aug-2022 |
Date of Acceptance | 01-Sep-2022 |
Date of Web Publication | 19-Sep-2022 |
Correspondence Address: Dr Muraleetharan Gopal Department of Pediatrics, Government Erode Medical College and Hospital, Perundurai, Erode, Tamil Nadu India
 Source of Support: None, Conflict of Interest: None
DOI: 10.4103/am.am_101_22
Introduction: COVID-19 pandemic-caused burden among the pediatric age group was less in terms of severity and mortality; indirect impacts of the pandemic on the mental health of children are huge and largely unnoticed. The main objective of this exploratory study was to analyze the association between screen time exposures among preschool children aged 3–6 years during the lockdown period in Tamil Nadu, India. Materials and Methods: An exploratory and anonymous population-based e-survey through social networks, including social media platforms (Facebook, LinkedIn, and WhatsApp) and researchers' acquaintances (email), using a snowball sampling strategy was conducted among parents of preschool children (aged 3–6 years) residing in different states of Tamil Nadu. Data were collected using Google Forms, and statistical, analysis was conducted. Results: Among 427 study participants, the mean age of screen introduction was 19.88 ± 11.73 months, and the mean age of independent operation of screen devices was 3.29 ± 1.16 years. Demanding extra attention (25.53%), temper tantrums (21.31%), increased aggressiveness (19.90%), more fussy (18.74%), altered night sleep (18.5%), and clinging (18.27%) were the frequently reported behavioral changes apart from increased screen time (60.88%) and decreased physical activity (28.80%) during the lockdown period. Conclusion: Excessive screen time beyond the recommended 1 h/day was seen in 94.1% of children, and screen exposure was inversely correlated with the duration of outdoor play. Among the behavioral changes, temper tantrums and fussiness were found to be significantly associated with increased recreational screen time.
Keywords: Behavioral well-being, mental health, preschoolers and COVID-19 lockdown, screen time, temper tantrums
How to cite this article: Gunasekaran A, Gounder Karupannagounder VR, Gopal M, Periasamy P, Vajiravelu S, Gunasekaran S. Association between screen time and psychosocial and behavioral well-being of preschoolers during the COVID-19 lockdown in Tamil Nadu. Apollo Med 2022;19:234-40 |
How to cite this URL: Gunasekaran A, Gounder Karupannagounder VR, Gopal M, Periasamy P, Vajiravelu S, Gunasekaran S. Association between screen time and psychosocial and behavioral well-being of preschoolers during the COVID-19 lockdown in Tamil Nadu. Apollo Med [serial online] 2022 [cited 2023 Feb 3];19:234-40. Available from: https://apollomedicine.org/text.asp?2022/19/4/234/356348 |
Introduction | |  |
Routines, social interactions, and friendships are among the most important factors responsible for children's normal psychological development. Strict social distancing measures, prolonged school closures, parental stressors and loss of loved ones are likely to affect children and adolescents' well-being in addition to specific psychological effects of quarantine and isolation.[1],[2] According to the Centers for Disease Control and Prevention, 4.4 million children aged 3–17 years have been diagnosed with anxiety, and 1.9 million have been identified with depression because of home quarantine due to COVID-19.[3] It becomes important to determine how extended school closures, stringent social-distancing steps, and the pandemic itself have impacts on the mental health status of children.[4]
On the other hand, an increased exposure to media gadgets as a result of home confinement and online schooling has laid open pathways to screen time-induced behavioral and emotional disturbances in young children.[5] Despite growing literature evidence worldwide, we did not find any study in Tamil Nadu that intends to explore the relationship between screen exposure and behavioral and emotional problems during a confinement situation[6],[7]. We decided to focus attention on the emotional/behavioral responses of children in the preschool age group (3–6 years) for the following reasons: establishment of daily routines, as kids are primed in Montessori and Kindergarten, for adapting to regular schools. Important developmental milestones such as sphincter control, emotional self regulation, falling asleep independently are achieved during this period. Delays and regressions in acquired capacity due to pandemic disruptions in the child's routine and parental care can be evaluated.[6],[7] After being introduced to screen devices by parents and caretakers in early infancy, screen time is stabilized in the 3–6 years age group after a dramatic increase in the first 2 years of life. Children learn to operate media devices independently, and they start charting their own screen hours. In this age group, children may not explicitly express their thoughts and emotional difficulties. Pediatricians and parents have to proactively look for cues from behavioral changes.[8],[9]
Aims and objectives
Therefore, the main objective of this exploratory study was to analyze the association between screen time exposure during the lockdown period in Tamil Nadu due to the COVID-19 outbreak and the emotional and behavioral problems of preschool children aged 3–6 years. Specifically, our aim was to calculate the time duration and conditions of exposure to screens on various digital media devices at home, considering it as the independent variable when studying its relationship with parents' perception of children's emotional and behavioral state during the confinement period (dependent variable). We hypothesized that higher screen time exposure during the lockdown would lead to higher risks of emotional and behavioral problems in children.
Materials and Methods | |  |
This was a cross-sectional questionnaire-based descriptive study. The study was planned and conducted for 6 months, from January 2021 to June 2021, through an online platform and social media networks. An exploratory and anonymous population-based e-survey was conducted among parents of preschool children in Tamil Nadu. Children aged between 3 and 6 years residing in any of the districts of Tamil Nadu were included in the study after obtaining the Institutional Ethical Committee approval. Children studying Montessori levels 1, 2, and 3 or pre-KG, LKG, and UKG in matriculation schools (aged 3–6 years) were included in the study. Children with severe visual or hearing impairments and children with global developmental delays were not included in the study. Children whose parents refused consent were also excluded from the study.
Zhao et al. have studied the relationship between excessive screen time and psychosocial well-being in preschool children in Shanghai province, China.[10] With the above study as a reference, taking 53% of participants exceeding 2 h of screen time/day, the estimated sample size at 5% absolute precision at 80% power of the study is 382. Adding a 10% nonresponse rate, the total sample size comes to around 421 participants.
Data collection
A semi-structured and self-reported questionnaire containing informed consent with five sections, i.e., (1) Sociodemographics (14 questions), (2) Childbirth and developmental history (5 questions), (3) Screen introduction and interaction (10 questions), (4) Social, emotional, and behavioral changes seen in children during lockdown (1 question with 18 symptoms to choose), and (5) Screen time calculations (5 questions), was utilized during data collection. The symptoms described in section 4 of the questionnaire were identified on the base of previous literature on parental responses to the behavioral changes noticed in their children during the pandemic. The questionnaire (English and regional language Tamil) was piloted among 20 parents whose wards were studying in the Montessori schools in the nearby locality. Necessary modifications were made to the questionnaire, and it was converted to suit the online format. Nonprobability sampling (purposive sampling) techniques were used to collect the primary data from the participants.
Tool
The semi-structured ad-hoc questionnaire was incorporated into the Google survey tool (Google Forms). A shareable link was generated and disseminated publicly on various social media outlets (e.g., Facebook, WhatsApp, etc.). Similarly, the link was also shared personally to the contact lists of the investigators and coinvestigators, and participants were recruited using a snowballing strategy. For data collection, the investigators used online approaches (as opposed to the originally planned face-to-face interview-based data collection) due to school closures and COVID preventive measures during the pandemic. Initially, information for the participants was provided in the invite message, and the informed consent of the respondents was obtained through an e-survey.
Data collected through Google Forms were transferred to Microsoft Excel for data sorting and coding. Data were statistically evaluated with IBM SPSS Statistics for Windows, Version 20.0., IBM Corp., Chicago, IL, USA. Descriptive statistics were reported as the mean standard deviation for continuous variables and frequencies (percentage) for categorical variables. An independent t-test was used to find the significant difference. Pearson correlation was used to find the association between two numerical data. All statistical tests were considered significant at a 95% confidence interval with P < 0.05.
Results | |  |
There were 430 responses through Google Forms and 20 responses collected through direct interviews. The online responses were received from 35 districts of Tamil Nadu. Among the online submissions, 27 responses were excluded as some children were beyond the target age group of our study; a few were incomplete responses and double entries. Finally, 427 participants were enrolled in our study, and the mean age of the study population was 4.53 ± 1.12 years [Figure 1]. The mean body mass index (BMI) of 15.58 ± 2.29 was seen in our study population. Among them, 257 children (60.2%) had BMI in the normal range, 128 (30%) were underweight, and 42 (9.8%) belonged to the overweight/obese category [Table 1]. The majority of the children (n = 255, 59.7%) in our study were born out of the cesarean section, and 50 (11.7%) of them were low birth weight babies at birth. | Table 1: Distribution of anthropometric parameters between the gender among the study participants (n =427)
Click here to view |
In our study population, the introduction of screen devices to children was seen as early as 2 months of age, and 37.7% of children were exposed to screen devices by 1 year of age. The mean age of the child when television/mobile/computer has been shown purposefully was around 19.88 ± 11.73 months [Figure 2]. Among our study participants, 72.4% and 91.6% had been exposed to screen-based media by 2 and 3 years of age, respectively. Children learned to handle the gadgets on their own from 1 year of age. The mean age of children starting to operate a smartphone/television independently was around 3.29 ± 1.16 years [Figure 3]. | Figure 2: Distribution of age (in months) of the child when television/mobile/computer was shown to him purposefully (n = 427)
Click here to view |
 | Figure 3: Distribution of age of the child who started to operate a mobile/television independently in years (n = 427)
Click here to view |
Most of the parents show screen devices while giving food (32%), followed by online classes (31%), storytelling and rhymes (22.48%), making them quiet (16.62%), and before sleeping (5.85%). Cartoon shows and rhymes and stories as visuals were the top two frequently viewed screen contents in our study population [Figure 4]. However, only about two-thirds of the children were under constant supervision by adults during the usage of screen devices [Figure 5]. | Figure 4: Distribution of contents viewed by children on television/mobile/computer (n = 427)
Click here to view |
 | Figure 5: Distribution of supervision of children's screen time by adults (n = 427)
Click here to view |
When screen devices are refused, 61.83% of children (n = 264) respond with cries and tantrums, followed by 13.11% isolating themselves (n = 56) and 12.18% turning aggressive and hitting their parents (n = 52). Around 50.1% of study participants (n = 214) tend to demand screen time repeatedly.
During the school closures and lockdown restrictions, approximately one-half of the study participants (n = 207, 48.5%) indulged in outdoor play activities for the recommended 2 h [Figure 6]. In our study, the majority of parents reported increased screen time (60.88%), followed by a perceived decrease in physical activity (28.80%). Major behavioral changes noticed among children were demanding extra attention and care (25.53%), temper tantrums (21.31%), increased aggressiveness (19.90%), more fussy and defiant (18.74%), altered night sleep (18.5%), and clinging (18.27%) [Table 2]. | Figure 6: Distribution of outdoor play hours of children daily (n = 427)
Click here to view |
 | Table 2: Distribution of social, emotional, and behavioral changes in the child during lockdown (n =427)
Click here to view |
In our study population, the mean screen time spent for online classes is 1.17 ± 1.11 h/day. Television continued to be the major contributor to recreational screen time with a mean of 1.74 ± 1.44 h, followed by smartphone or tab devices with a mean of 1.45 ± 1.24 watching hours. The mean total daily screen time exposure for the children in our study group was 4.67 ± 2.81 h, with nearly three-fourths of the total screen time being spent on entertainment shows and other recreational purposes, averaging 3.48 ± 2.25 h [Table 3]. The screen time usage was higher in children residing in urban areas compared to children from semi-urban and rural areas; however, the difference was not statistically significant [Table 4] and [Table 5]. | Table 3: Distribution of screen time calculation among the study participants (n =427)
Click here to view |
 | Table 4: Distribution of recreational screen time versus type of locality (n =427)
Click here to view |
 | Table 5: Distribution of total screen time versus type of locality (n =427)
Click here to view |
As the hours of children indulging in outdoor play activities increased, there was a significant decrease in the recreational and total screen time viewing [Table 6]. Among the socioemotional and behavioral changes noticed in the study population, temper tantrums and fussiness were found to be significantly associated with increased recreational screen time [Table 7]. Other behavioral changes did not show any significant difference between total and recreational screen time [Table 8]. | Table 6: Correlation between screen time and outdoor play activity hours (n =427)
Click here to view |
 | Table 7: Distribution of recreational screen time calculation versus social, emotional, and behavioral changes among the study participants (n =427)
Click here to view |
 | Table 8: Distribution of total screen time calculation versus social, emotional, and behavioral changes among the study participants (n =427)
Click here to view |
Discussion | |  |
In our study, among parental education status, 82.5% of mothers and 72.1% of fathers have completed college education (under graduation and/or postgraduation). In a similar study by Morgül et al. in the U.K, 74.4% of mothers and 58.9% of fathers had completed a higher education degree or postgraduate studies.[11] Orgilés et al., in their study examining the emotional impact of the quarantine on children and adolescents from Italy and Spain,[5] have documented the higher educational level of the parents/caregivers, with 70.5% in Spain and 56.7% in Italy attending college for an undergraduate degree or more. These data show that higher education opportunities in Tamil Nadu are comparable with the United Kingdom and southern European countries.
Meena et al. have documented screen introduction beginning as early as 2 months of age, and the median age of first exposure being 10 months (interquartile range 8–12).[12] Similarly, screen devices were introduced at 2 months of age in our study.
Shah et al. have documented that the mean daily screen time of 2.7 ± 1.7 h, with an average television screen time of 1.6 ± 1.1 h. About 17.2% of the participants met the AAP recommendation of 1 h or less daily screen time, and 93.9% of the children had at least 1 h of outdoor play activity[13]. Samya et al.'s study found that the show rate of excessive screen time (>1 h/day) among children aged 2–5 years was 73%. The mean total daily screen time exposure for the children in the 2–5 years group was 2.8 ± 2.23 h/day, with a television viewing mean of 1.59 ± 1.43 h and smartphones contributing to 1.35 ± 1.45 h.[14] Comparatively, the mean daily screen time was 4.67 ± 2.81 h, and the mean daily television screen time was 1.74 ± 1.44 h in our study. About 94.1% of our study participants had more than the AAP-recommended daily screen time of 1 h, and around 83.9% of the children had 1 h or more of outdoor playtime.
The study by Shah et al. and Samya et al. was conducted in 2019, well before the COVID times, and our study was done in 2021, 1 year into the pandemic, in the aftermath of lockdown restrictions and school closures. These differences clearly illustrate the dramatic increase in screen exposure time duringa lockdown and school closures.[13],[14]
Jiao et al., as a part of the China-EPA-UNEPSA collaborative working group, conducted a preliminary study in the Shaanxi province during the pandemic to investigate the Chinese children's behavioral and emotional reactions to COVID-19.[15] Clingy, inattention, irritability, worry, and obsessive request for updates were the most common psychological and behavioral problems noticed in their study population of 320 children aged 3–18 years. The Chinese study was conducted in February 2020 during the early phase of the pandemic, when the threat posed by the novel coronavirus and uncertainty was looming very large. Furthermore, the inclusion of older children and adolescents in their study would have led to explicit manifestations of behavioral problems.[15]
Raj et al., in their cross-sectional study to identify the prevalence and determinants of screen time among children under 5 years of age in Malaysia,[16] have documented the excessive screen time of more than the WHO-recommended 1 h/day in 91.3% of their study population among the 2–5 years of age group. Similarly, in our study, the total screen time was more than 1 h/day in 94.1% of preschool children.
In the study by Francisco et al., Italian children presented with fewer psychological and behavioral symptoms compared with Portuguese and Spanish children.[17] The symptoms such as a child crying easily (17.6%), sleeping difficulties (16.8%), and child dependent on parents (26.6%) in their study were comparable to a child being more fussy and defiant (18.74%), altered night sleep (18.5%), and demanding extra attention and care (25.5%) in our study; other symptoms like a child eating a lot (23.2%), the child has difficulty in concentrating (23.9%), and child worrying when one of the parents leave the house (23.6%) were relatively higher than overeating (17.09%), impaired concentration (14.98%), and clinging (18.3%) noticed in our study participants.
Pisano et al., in their qualitative report on exploratory data on the possible emotional/behavioral correlates of COVID-19 lockdown in Italian children, have documented 17.6% new-onset fear and 4.4% enuresis in the 4–6 years age group.[18] This would have resulted in relatively lower manifestations of fearfulness and enuresis in our study.
Hosokawa and Katsura, in their study, found that using mobile devices without educational content, such as smartphones and tablets, was associated with a higher likelihood of behavior problems (i.e., conduct problems and hyperactivity/inattention difficulties).[19] In our study, temper tantrums and fussiness were found to be significantly associated with increased recreational screen time.
A large multinational longitudinal study, the Co-SPACE project, has been tracking the mental health of school-aged children and young people aged 4–16 years (at the beginning of the study in March 2020) throughout the COVID-19 crisis.[20] Till the publication of interim report 8, over 12,500 parents/caretakers and 1300 adolescents have taken part in the Co-SPACE survey at baseline, submitting online surveys on a monthly basis. Preliminary findings from the Co-SPACE study showed that parents/caretakers of 4–10 years old in the UK reported significant increases in emotional, behavioral, and restless/attentional difficulties as the latest lockdown progressed over a 1-month period in January 2021.
Hence, the behavioral problems noticed in our study participants, i.e., demanding extra attention and care (25.53%), temper tantrums (21.31%), increased aggressiveness (19.90%), more fussy and defiant (18.74%), altered night sleep (18.5%) clinging (18.27%), etc., could be well attributed to the COVID-19 pandemic and its consequences–social distancing, extended lockdown, and school closures. In concurrence with the displacement hypothesis, we found that the increased duration of outdoor play significantly decreased the time spent in front of the screens. Therefore, increased screen time (60.88%) and decreased physical activity (28.80%) could be considered modifiable risk factors to mitigate behavioral and emotional disturbances in young children.
Limitations
Our study participants were recruited from almost all the districts of Tamil Nadu. Being a cross-sectional study, a casual association could not be established between the variables. There was a possibility of “recall bias” when parents reported the screen introduction and exposure time in an e-survey. Questionnaire-based methods still hold their place in screen time assessments and are comparable with diary-based calculations.
Conclusion | |  |
The adverse psychosocial effects of COVID-19 and its prevention strategies–social distancing, lockdown, and school closures, in young children, need urgent attention by policymakers, and appropriate protective measures should be initiated at the earliest. Parents, teachers, and pediatricians should act on the modifiable risk factors to mitigate the emergence of the child psychiatric epidemic from the evolving pandemic.
Acknowledgment
We sincerely thank each and every one of the participants for taking the time to complete our survey. The authors thank the Government Erode Medical College and Hospital, Perundurai, Tamil Nadu, for providing the necessary facilities.
Conflicts of interest
There are no conflicts of interest.
IEC/IRB approval
Government Erode Medical College and Hospital, Perundurai, Erode, Institutional Ethics Committee (Ref No-IEC/001-03/GEMCand H/2020. Dated: July 31, 2020).
Funding
Nil.
Credit authorship contribution statement
Dr. Anuradha Gunasekaran (AG) and Dr. Vajiravelu Suganthi (VS) had the idea for this study. Dr Muraleetharan Gopal (M.G.) and Panneerselvam Periasamy (P.P.) are the principal investigators of the research work. AG, MG, Sasikala Gunasekaran (GS), and Dr. Viswanathan Rangaswamy gounder Karupannagounder (VR) designed the study protocol. M.G. performed data collection, G.S. conducted the analyses, and VS drafted the manuscript. P.S., AG, and V. R. further edited the manuscript, and all gave the final approval.
References | |  |
1. | Marques de Miranda D, da Silva Athanasio B, Sena Oliveira AC, Simoes-E-Silva AC. How is COVID-19 pandemic impacting mental health of children and adolescents? Int J Disaster Risk Reduct 2020;51:101845. |
2. | Fegert JM, Vitiello B, Plener PL, Clemens V. Challenges and burden of the Coronavirus 2019 (COVID-19) pandemic for child and adolescent mental health: A narrative review to highlight clinical and research needs in the acute phase and the long return to normality. Child Adolesc Psychiatry Ment Health 2020;14:20. |
3. | Deolmi M, Pisani F. Psychological and psychiatric impact of COVID-19 pandemic among children and adolescents. Acta Biomed 2020;91:e2020149. |
4. | Spinelli M, Lionetti F, Pastore M, Fasolo M. Parents' stress and children's psychological problems in families facing the COVID-19 outbreak in Italy. Front Psychol 2020;11:1713. |
5. | Orgilés M, Morales A, Delvecchio E, Mazzeschi C, Espada JP. Immediate psychological effects of the COVID-19 quarantine in youth from Italy and Spain. Front Psychol 2020;11:579038. |
6. | Imran N, Aamer I, Sharif MI, Bodla ZH, Naveed S. Psychological burden of quarantine in children and adolescents: A rapid systematic review and proposed solutions. Pak J Med Sci 2020;36:1106-16. |
7. | Lee J. Mental health effects of school closures during COVID-19. Lancet Child Adolesc Health 2020;4:421. |
8. | Patra S, Patro BK, Acharya SP. COVID-19 lockdown and school closure: Boon or bane for child mental health, results of a telephonic parent survey. Asian J Psychiatr 2020;54:102395. |
9. | Cost KT, Crosbie J, Anagnostou E, Birken CS, Charach A, Monga S, et al. Mostly worse, occasionally better: Impact of COVID-19 pandemic on the mental health of Canadian children and adolescents. Eur Child Adolesc Psychiatry 2022;31:671-84. |
10. | Zhao J, Zhang Y, Jiang F, Ip P, Ho FK, Zhang Y, et al. Excessive ScreenTime and Psychosocial Well-Being: The Mediating Role of Body MassIndex, Sleep Duration, and Parent-Child Interaction. J Pediatr 2018;202:157-62.e1. doi: 10.1016/j.jpeds.2018.06.029. Epub 2018 Aug 9.PMID: 30100232. |
11. | Morgül E, Kallitsoglou A, Essau CA. Psychological effects of the COVID-19 lockdown on children and families in the UK. Rev Psicol Clín Con Niños Adolesc 2020;7:42-8. |
12. | Meena P, Gupta P, Shah D. Screen time in Indian children by 15-18 months of age. Indian Pediatr 2020;57:1033-6. |
13. | Shah RR, Fahey NM, Soni AV, Phatak AG, Nimbalkar SM. Screen time usage among preschoolers aged 2-6 in rural Western India: A cross-sectional study. J Family Med Prim Care 2019;8:1999-2002.  [ PUBMED] [Full text] |
14. | Varadarajan S, Govindarajan Venguidesvarane A, Ramaswamy KN, Rajamohan M, Krupa M, Winfred Christadoss SB. Prevalence of excessive screen time and its association with developmental delay in children aged < 5 years: A population-based cross-sectional study in India. PLoS One 2021;16:e0254102. |
15. | Jiao WY, Wang LN, Liu J, Fang SF, Jiao FY, Pettoello-Mantovani M, et al. Behavioral and emotional disorders in children during the COVID-19 epidemic. J Pediatr 2020;221:264-6.e1. |
16. | Raj D, Mohd Zulkefli N, Mohd Shariff Z, Ahmad N. Determinants of Excessive Screen Time among Children under Five Years Old in Selangor, Malaysia: A Cross-Sectional Study. Int J Environ Res Public Health 2022;19:3560. doi:10.3390/ijerph19063560. |
17. | Francisco R, Pedro M, Delvecchio E, Espada JP, Morales A, Mazzeschi C, et al. Psychological symptoms and behavioral changes in children and adolescents during the early phase of COVID-19 quarantine in three European Countries. Front Psychiatry 2020;11:570164. |
18. | Pisano L, Galimi D, Cerniglia L. A qualitative report on exploratory data on the possible emotional/behavioral correlates of Covid-19 lockdown in 4-10 years children in Italy. “ PsyArXiv. doi:10.31234/osf.io/stwbn. https://psyarxiv.com/stwbn/. [Last accessed on 2022 Sep 09]. |
19. | Hosokawa R, Katsura T. Association between mobile technology use and child adjustment in early elementary school age. PLoS One 2018;13:e0199959. |
20. | |
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8]
|