Association of High Screen-Time Use With School-age Cognitive, Executive Function, and Behavior Outcomes in Extremely Preterm Children

Key Points

Question  Is increased screen time at early school age associated with an increase in risk of developmental and behavioral problems for extremely premature infants?

Findings  In this cohort study including 414 children who had been born extremely prematurely, high screen time of 2 hours or more per day was associated with an increase in risk of cognitive, executive function, and behavioral problems at early school age among extremely premature children after adjusting for center, male sex, and gestational age, severe retinopathy of prematurity, and social determinants. The maximum number of hours of screen time reported for these children was 40.3 hours per week.

Meaning  These findings suggest that a high level of screen time contributes further to an increase in risk of cognitive, executive function, and behavior outcomes at age 6 to 7 years in extremely premature children, supporting the need for health care professionals to discuss both the benefits and risks of screen time with families and share the American Academy of Pediatrics recommendations.

Importance  Both preterm birth and increased screen time are known to be associated with an increase in risk of developmental and behavioral sequelae. The association between high screen time or a television or computer in the bedroom in early school age and adverse cognitive, executive function, language, and behavior outcomes of extremely preterm children (EPT) is not well understood.

Objective  To assess the association of high screen time with cognition, language, executive function, and behavior of EPT children aged 6 to 7 years; a second objective was to examine the association between high screen time and rates of structured physical activity and weight.

Design, Setting, and Participants  This cohort study was a secondary analysis from the Eunice Kennedy Shriver National Institute of Child Health and Human Development Surfactant Positive Airway Pressure and Pulse Oximetry Randomized Trial Neuroimaging and Neurodevelopmental Outcomes school-aged cohort and includes 414 EPT children born between February 1, 2005, and February 28, 2009, and evaluated in between 2012 and 2016 at ages 6 years 4 months to 7 years 2 months. The study was conducted from July 7, 2012, and August 15, 2016, and data were analyzed between December 10, 2018, and April 1, 2021.

Exposures  Cohorts included children exposed to low (≤2 hours per day) vs high (>2 hours per day) amounts of screen time and by the presence (no vs yes) of a television/computer in the bedroom.

Main Outcomes and Measures  In addition to growth parameters, assessments included the Wechsler Intelligence Scale for Children-IV, the Behavior Rating Inventory of Executive Function, the Developmental Neuropsychological Assessment, the Conners 3rd Edition–Parent Short-Form, and the Social Communication Questionnaire.

Results  Of the 414 children included in the analysis, 227 (55%) were boys; mean (SD) birth weight was 870.6 (191) g. A total of 238 children (57%) had high screen time and 266 (64%) had a television/computer in their bedroom. In multivariable linear regressions adjusted for center, male sex, gestational age, and social determinants of health, high screen time was independently associated with the following mean (SE) test score changes: lower full-scale IQ (−3.92 [1.64]; P = .02); an increase in association with deficits in executive functions, including metacognition (8.18 [3.01]; P = .007), global executive function (7.49 [2.99]; P = .01), inhibition (−0.79 [0.38]; P = .03), and Conners 3rd Edition–Parent Short-Form inattention (3.32 [1.67]; P = .047). A television/computer in the bedroom was associated with an increase in inhibition (−0.80 [0.39]; P = .04) and hyperactivity/impulsivity (3.50 [1.75]; P = .046) problems.

Conclusions and Relevance  The findings of this study suggest that high screen time contributes to adverse cognitive, executive function, and behavior outcomes at ages 6 to 7 years in children born at less than 28 weeks. These findings support the need for clinicians to have heightened awareness of the risks for EPT children and discuss both the benefits and risks of screen time with families.

The availability of screen devices in homes continues to increase. From 2011 to 2020, the percent of families with a smart phone increased from 41% to 97%, a tablet from 8% to 75%, and the child owning a tablet from less than 1% to 44%.¹ Studies reporting screen time describe a spectrum of mobile devices, including television, computers, video games, smart phones, and tablets. A Canadian study identified that 94% of preschool children aged 5 years or younger watched television and 38% played video or computer games. Increased screen time has been associated with cognitive,^2,3 executive function,⁴ language,^5-7 behavior and attention disorders,⁸ and academic,⁹ sleep,¹⁰ and health problems.^11,12 Studies suggest the association between screen time and executive function is mediated by the type of media use, the content, and the age of the child.^13-15 A study of children aged 2 to 3 years demonstrated better executive function skills and delayed gratification after viewing an educational app rather than a cartoon.¹⁴

Television viewing has been negatively associated with the development of cognitive abilities and executive function and positively associated with sleep problems, internalizing and externalizing behavior, depression, and anxiety in children.^10,13,16-18 Christakis et al¹⁹ reported that increased hours of television watching in children aged 1 and 3 years suggested the probability of increased risk of attention problems at age 7 years. In 2013, the American Academy of Pediatrics (AAP)²⁰ recommended not more than 2 hours of screen time for children older than 2 years. As of 2016, however, the AAP recommended that children aged 2 to 5 years have screen use limited to 1 hour per day of high-quality programs, parents place consistent limits on media for children aged 6 years and older, and children not have a television or computer in their bedroom.²¹ The 2016-2017 National Survey of Children’s Health reported that more than one-third of children aged 6 to 11 years in the US spend 4 or more hours of screen time per weekday.²² These national data reflect that we are living in the electronic media age. There is increasing evidence that excessive screen time has deleterious effects on children who were born at full term, including language and developmental problems, behavior and socialization disorders,¹⁶ fine motor coordination, academic problems,^6,11,23-25 and health problems.^16,25

Children who were born prematurely, who are at increased risk of underlying brain abnormalities,^26-28 have been shown to be at increased risk of behavioral self-regulation problems,²⁹ executive function deficits,³⁰ attention-deficit disorder,³¹ gross and fine motor deficits, and academic challenges. It is not known whether a high amount of screen time contributes further to these behavior and learning problems. In addition, children born prematurely have higher rates of cerebral palsy and motor coordination disorder, which, in turn, may contribute to more sedentary behavior and screen time.^32,33 It was previously reported for the Surfactant Positive Airway Pressure and Pulse Oximetry Randomized Trial (SUPPORT), Neuroimaging and Neurodevelopmental Outcome (NEURO) cohort³⁴ that extremely premature children who were overweight and obese (mass index ≥85th percentile) at age 6 to 7 years spent more time with screen activity than their peers who were normal weight. There are limited data on the association of screen time with cognitive and behavior outcomes in the high-risk preterm population.

The primary objective of this cohort study was to assess the association of screen time with cognition, language, executive functions, and behavior at early school age within a population of children born extremely prematurely. It was hypothesized that high screen use (>2 hours per day) is associated with an increase in rates of cognitive, executive function, and behavior disorders. A secondary objective was to examine the association between high screen time and rates of structured physical activity, such as soccer or dance, and rates of overweight (body mass index ≥85th percentile) and obesity (body mass index ≥95th percentile).

This study of screen time is secondary to the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Neonatal Research Network (NRN) SUPPORT NEURO school age cohort,³⁵ which was a secondary study to SUPPORT, a randomized, multicenter trial of ventilation and oxygenation management strategies among infants at 24 to less than 28 weeks’ gestation. Children in the NEURO study cohort representing 16 NRN centers included 386 extremely premature children born from February 1, 2005, to February 28, 2009, with both early and late cranial ultrasonography (CUS) data, evaluated in follow-up between 2012 and 2016 at age 6 years 4 months to 7 years 2 months.^36-38 Children who were bilaterally blind and those with moderate or severe cerebral palsy were excluded. All data on screen time were collected once at the 6- to 7-year visit. The current study includes 414 children because late cranial ultrasonography was not a requirement for inclusion. The study was approved by the institutional review boards of all participating centers and the institutional review board of Research Triangle Institute International and the data coordinating center for the NICHD NRN. Informed written consent was obtained from parents. Parents and children received compensation. Quiz Ref IDThis study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline. The study was conducted from July 7, 2012, and August 15, 2016, and data were analyzed between December 10, 2018, and April 1, 2021.

Quiz Ref IDStandard maternal, neonatal, and child data were retrieved from the NICHD NRN SUPPORT and NEURO databases. The following intelligence and executive function tests were administered. The Wechsler Intelligence Scale for Children IV (WISC IV)³⁹ is a standardized intelligence test for children aged 6.0 to 16.11 years with verbal comprehension, perceptual reasoning, working memory, and processing speed indices, as well as a full-scale IQ score. The Behavior Rating Inventory of Executive Function ⁴⁰ includes a parent report assessment of executive function behaviors at home for children aged 5 to 18 years. Scores of interest for this cohort are the Behavior Regulation Index (ability to self-monitor and inhibit), Metacognition Index (planning and problem solving), and Global Executive Composite (overall index of executive functions). Higher t scores (>60) and percentiles indicate greater risk. The Developmental Neuropsychological Assessment (NEPSY II)⁴¹ is used to assess neuropsychological development in children aged 3 to 16 years in 6 functional domains: Auditory Attention, Inhibition Naming Task, Inhibition Inhibition combined, Design Copying Process, and the Memory for Names and Memory for Names Delayed total scores. NEPSY scores lower than 8 indicate greater risk.

Two behavior questionnaires were administered to the parents. The Conners 3rd Edition–Parent Short-Form (Conners)⁴² assesses attention-deficit/hyperactivity disorder and common comorbid problems in children aged 6 to 18 years. Domains of interest included inattention and hyperactivity/impulsivity. These scores are categorized as elevated (considered concerning at scores ≥65; 1.5-2 SDs above the mean) and very elevated (considered substantially concerning at scores ≥70; >2 SDs above the mean ). The Social Communication Questionnaire⁴³ is a questionnaire with 40 yes/no items appropriate for children aged 4 years or older. The total score cutpoint of greater than or equal to 15 has been used to identify children at increased risk of autism. Subscores include qualitative abnormalities in reciprocal social interaction, communication, and restricted, repetitive, and stereotyped patterns of behavior.

A brief parent report of structured physical activity and sedentary behavior questionnaire derived from the NICHD study on growth and calcium intake was completed.⁴⁴ The activity questionnaire included 12 questions that reflect either sedentary screen activity (ie, television, tablet, or computer time) or structured physical activity (ie, sports or dance). Parents reported the number of minutes or hours per day during the 5 weekdays and number of minutes or hours per day on the weekends of child participation in active (playing video games) or passive (watching television) screen-time activity and if the child had a television or computer in their bedroom.

Data sets included SUPPORT and NEURO maternal, neonatal, and school-age data. Data were initially analyzed to assess both the AAP 2013 less than or equal to 2.0 hours²⁰ and AAP 2016 less than or equal to 1.0 hour²¹ cutpoints. There were only 48 children with screen time less than or equal to 1 hour, limiting power, and in adjusted analyses, there were no significant group differences identified by less than or equal to 1 hour. Therefore, because the median screen time value for our cohort was 2 hours and some investigators^45-48 have reported an association of the 2-hour cutpoint with developmental and behavior outcomes, child groups were defined as low users (≤2.0 hours per day) vs high users (>2 hours per day) of screen time, consistent with the AAP 2013 guidelines.²⁰

A total of 414 children meeting the inclusion criteria had screen time data. We estimated the power for comparisons of mean scores for children with high (n = 238) vs low (n = 176) overall screen time on a continuous outcome (eg, scale scores). With these sample sizes, we would have 91% power to detect a small to medium-sized association (F = 0.15), assuming a P value of .05 and inclusion of up to 10 covariates with a combined R² value of 0.10. The F measure is an effect size used for analysis of variance and analysis of covariance; the F value is a ratio of SDs.

Bivariate analyses were conducted to examine the characteristics of children with low vs high screen time and for those with and without a television/computer in their bedroom, using χ² tests or Fisher exact tests, depending on cell size. Mixed-effects regression models were run to compare high vs low screen time and separately for a television/computer in the bedroom on cognition, executive function, language, and behavior. Each model included center as a random effect and controlled for antenatal, neonatal, social, and demographic factors that were significant in bivariate analyses at P < .05: male sex, gestational age, severe retinopathy of prematurity, maternal age younger than 20 years, White race, maternal educational level less than high school, and public insurance. Of these control variables, data were missing on educational level for 7 mothers (2%) and retinopathy of prematurity for 26 children (6%). Multiple imputation was used to impute missing values on the demographic factors. The specific type of model (eg, linear, logistic, and Poisson) was selected based on the distribution of the outcome variables. Analyses were conducted in SAS, version 9.4 (SAS Institute Inc).

A total of 414 children who met the inclusion criteria were analyzed by high (n = 238) vs low (n = 176) overall screen time. As presented in Table 1, social and demographic characteristics differed between the groups. A total of 227 (55%) were boys and 187 (45%) were girls; mean (SD) birth weight was 870.6 (191) g. Quiz Ref IDHigh screen time was associated with younger maternal age (mean [SD], 27.0 [6.6] vs 28.7 [7.3] years; P = .01) and non-White race (Black, 92 [39%] vs White, 83 [35%]; P = .01). Within the cohort, 176 of 414 (43%) of the children met the screen time recommendation of 2 hours or less per day. Television/computer in the bedroom was also associated with younger maternal age (mean [SD], 26.7 [6.8] vs 29.5 [6.9] years; P < .001) and non-White race (Black, 112 [42%] vs White, 88 [33%]; P < .001). In addition, a television/computer in the bedroom was associated with a lower maternal educational level (80 [30%]; P = .01) and public insurance (155 [58%]; P < .001). There were no significant differences in infant medical morbidities.

Child characteristics are reported in Table 2. In this cohort, 238 (57%) of the children spent more than 2 hours per day with screen time and 266 (64%) had a television/computer in their bedroom. The peak number of hours of screen time reported for the children was 40.3 hours per week. Children with high screen time were more likely to have lower mean (SD) minutes per day of structured physical activity than children with low screen time (8.07 [12] vs 4.42 [9]; P < .001). The range, however, extended to the recommended 60 minutes per day for both the low screen and television/computer groups. There was also an association of high screen time with overweight (62 [28%] children; P < .001) and obesity (33 [15%] children; P < .001).

Quiz Ref IDTable 3 displays the comparisons of cognitive and executive function test results by screen time. On the WISC-IV, children with high screen time had significantly lower mean full-scale IQ scores after adjustment for center, male sex, gestational age (weeks), maternal age younger than 20 years, White race, retinopathy of prematurity, public insurance, and maternal educational level less than high school (mean [SE] difference, −3.92 [1.64]; P = .02). Although children with high screen time had significantly lower mean scores for WISC-IV verbal comprehension and perceptual reasoning subscales in the unadjusted comparisons, these differences were no longer significant in the adjusted comparisons. After controlling for other factors, high screen time was associated with significantly higher mean scores on the Behavior Rating Inventory of Executive Function metacognition index based on t scores (mean [SE] difference, 2.82 [1.34]; P = .04) and percentiles (mean [SE] difference, 8.18 [3.01]; P = .007) and on the global executive composite percentiles (mean [SE] difference, 7.49 [2.99]; P = .01). Children with high screen time also had significantly lower NEPSY Inhibition inhibition scores (mean [SE] difference, −0.79 [0.38]; P = .03) and significantly higher Conners inattention scores (mean [SE] difference, 3.32 [1.67]; P = .047) than those with low screen time based on the adjusted comparisons.

Quiz Ref IDResults for comparisons by having a television/computer in the child’s room are reported in Table 4. Although full-scale IQ and 3 of the 4 WISC-IV subscale scores (verbal comprehension, perceptual reasoning, and working memory) differed significantly across the 2 groups in the unadjusted comparisons, these differences were not significant when adjusted for demographic factors. After controlling for other factors, children who had a television/computer in their room had significantly lower NEPSY Inhibition inhibition scores (mean [SE] difference, −0.80 [0.39]; P = .04) and significantly higher Conners hyperactivity/impulsivity scores (mean [SE] difference, 3.50 [1.75]; P = .046).

Children with a history of preterm birth are known to be at increased risk of deficits in cognitive and executive functions in comparison with those born term.^49-53 Studies have shown an association of increased screen time with cognitive and executive function deficits in the general population.^13,14,54-56 Our data on a well-described cohort of children born extremely prematurely support the independent association between high screen time and a decrease in cognitive and executive functions after adjustment for center, male sex, and social-environmental factors. In this cohort, 57% of the children spent more than 2 hours per day with screen time and 64% had a television/computer in their bedroom. Social and environmental characteristics associated with poverty were associated with both an increase in screen time and a television/computer in the bedroom. Our findings support our hypotheses that high screen use is associated with an increase in rates of low cognitive and executive functions. After adjustment for multiple confounders, high screen time was associated with lower full-scale IQ and an increase in problems with metacognition, global composite of executive function, and NEPSY inhibition, and is consistent with reports in term children. Decreased executive function in children born at term has been associated with an increase in television exposure⁵⁷ and high-dose app use (≥30 minutes per day).⁵⁸ In addition, longitudinal studies have reported that high screen time is associated with subsequent lower developmental scores and educational achievement.^3,50,59 The Adolescent Brain Cognitive Development (ABCD) Study of 4524 US children aged 8 to 11 years reported that meeting the guideline of 2 hours or less of recreational screen time per day was associated with significantly higher global cognition.⁴⁵ In addition, although prior investigators have reported an association between an increase in screen time and language outcomes,^6,7,46,60,61 our adjusted analyses did not reach significance.

Our findings also support our hypothesis that high screen time was associated with an increase in rates of behavior disorders. This association in our cohort was limited to attention deficit relative to screen time and hyperactivity/impulsivity related to a television/computer in the bedroom. Other investigators have identified an association of either an increase in screen time or having a television/computer in the bedroom with an increase in rates of attention-deficit/hyperactivity disorder, attention problems, and hyperactivity.^62-64 In a large Canadian study, children with more than 2 hours per day of screen time had a 5-fold increased odds for clinically significant externalizing problems compared with those with less than 30 minutes of screen time per day and were 5.9 times more likely to report clinically significant inattention problems.⁴⁷ Guerrero et al,⁴⁸ in a recent report from the ABCD study of US school children aged 8 to 11 years, reported fewer impulsive behaviors for children who met the recommendations for both low screen time (≤2 hours per day) and 9 to 11 hours of sleep per night. Only 11.5% of children in the study met the screen time recommendation. In our cohort, 43% of children met the recommendation at age 6 to 7 years. Although television/DVD/video viewing has been shown to be associated with children's social skills,⁶⁵ an association with Social Communication Questionnaire scores in our cohort was not present.

Relative to brain changes, Hutton et al⁶⁶ found an association between increased screen-based media use and lower microstructural integrity of brain white matter tracts supporting language and emergent literacy skills in healthy children aged 3 to 5 years. It is well documented that infants born extremely prematurely are at increased risk of brain injury, reduced brain volume, and reduced gray and white matter.^67-69 In addition, increased regional vulnerability of temporal lobes (language), frontal lobes (executive functions),⁷⁰ and cerebellum, and altered microstructure and connectivity have been reported both in the neonatal period and at school age.⁶⁹ These abnormalities are known to be associated with cognitive, behavior, and language outcomes.^27,71 We speculated that the association of screen time with executive functions may, therefore, be amplified in the preterm child compared with the typically developing child.

In addition, although not a primary outcome, our data showed an association between screen time and child overweight and obesity. This finding is consistent with a previous report on extremely premature infants³⁴ and others in the general population.^11,12,72 Increased screen time was also associated with lower structured physical activity levels. Mean activity levels for all study groups were substantially below the 60 minutes per day recommended.^73,74 The association of low physical activity and obesity with high screen time in children has been reported.^24,25,34 Factors contributing may be decreased physical stamina, lack of access to outdoor play activities, and a decrease in gross motor skill proficiency resulting in avoidance of physical activity.

A strength of this report is that, to the best of our knowledge, it is the first study of screen time association with school age cognitive, executive function, and behavior outcomes of children born extremely prematurely. Our models controlled for multiple child, family, and environmental confounders known to be associated with school age outcomes. A limitation of the study is that screen time and activity information were obtained by parent report and did not differentiate tablet from television or educational media vs games, and the presence of a television/computer in the bedroom did not account for the presence of a tablet. However, the study children were born between 2005 and 2009 and the study protocol was conceived before the escalation in use of tablets and smart phones by children. A further limitation is that analyses were not corrected for multiple comparisons, so it is possible that some significant differences may have occurred by chance. In addition, this was a cross-sectional study and so does not reflect causality, we did not include a term control group, parent but not teacher’s versions of the Behavior Rating Inventory of Executive Function and Conners measures were administered, parent report of screen time was for a typical 7-day week and was not cumulative, and parent-child at-home learning activities,⁷⁵ which can affect development, were not collected.

Although the use of electronic media can provide new and relevant educational information and learning opportunities for children, the results of this study provide evidence that high screen time and having a television/computer in the bedroom may contribute further to school age outcomes in children born extremely prematurely. Our findings support the need for clinicians to discuss both the benefits and risks of screen time with families and share AAP recommendations.²¹

Accepted for Publication: April 26, 2021.

Published Online: July 12, 2021. doi:10.1001/jamapediatrics.2021.2041

Corresponding Author: Betty R. Vohr, MD, Division of Neonatal Medicine, Department of Pediatrics, Women & Infants Hospital of Rhode Island, 101 Dudley St, Providence, RI 02905 (bvohr@wihri.org).

Author Contributions: Drs Bann and Das full access to all the data in the study and take responsibility for the integrity of the data and accuracy of the data analyses.

Concept and design: Vohr, Higgins, Hintz.

Acquisition, analysis, or interpretation of data: All authors.

Drafting of the manuscript: Vohr, McGowan, Bann.

Critical revision of the manuscript for important intellectual content: Vohr, McGowan, Das, Higgins, Hintz.

Statistical analysis: Bann, Das.

Obtained funding: Das, Hintz.

Administrative, technical, or material support: Higgins, Hintz.

Supervision: Higgins.

Conflict of Interest Disclosures: Dr Vohr reported receiving grants from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Neonatal Research Network (NRN) during the conduct of the study. Dr Bann reported receiving grants from the NICHD during the conduct of the study. Dr Das reported receiving grants from the National Institutes of Health cooperative agreement grant during the conduct of the study. Dr Hintz reported receiving grants from the NICHD NRN during the conduct of the study. No other disclosures were reported.

Funding/Support: The National Institutes of Health (M01 RR30, M01 RR32, M01 RR39, M01 RR54, M01 RR59, M01 RR64, M01 RR80, M01 RR70, M01 RR633, M01 RR750, M01 RR997, UL1 RR25008, UL1 RR25744, UL1 TR442), the NICHD (U10 HD21364, U10 HD21385, U10 HD21373, U10 HD27851, U10 HD27856, U10 HD27880, U10 HD27904, U10 HD34216, U10 HD36790, U10 HD40461, U10 HD40492, U10 HD40689, U10 HD53089, U10 HD53109, U10 HD53119, and U10 HD53124) and the National Heart, Lung, and Blood Institute (NHLBI) (via co-funding) provided grant support for the NRN’s Extended Follow-up at School Age for the Surfactant Positive Airway Pressure and Pulse Oximetry Randomized Trial (SUPPORT) Neuroimaging and Neurodevelopmental Outcomes (NEURO) Cohort.

Role of the Funder/Sponsor: Although the NICHD staff had input into the study design, conduct, analysis, and manuscript drafting, the comments and views of the authors do not necessarily represent the views of the NICHD. Data collected at participating sites of the NICHD Neonatal Research Network NRN were transmitted to Research Triangle Institute International, the data coordinating center for the network, which stored, managed, and analyzed the data for this study.

Group Information: The members of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network are listed in the Supplement.

Additional Contributions: We thank the children and their parents who participated in this study.

Additional Information: Extended Follow-up at School Age for the SUPPORT NEURO Cohort: NCT00233324.