Screen time and its association with adolescents' lifestyles in a city in the Brazilian Northeast

Objective : To associate screen time with food, physical activity, sleep and sociodemographic variables in Brazilian adolescents, students of urban public institutions. Methods : Observational, cross-sectional, quantitative, analytical study approved by the Ethics Committee in Research on Human Beings of the Federal University of Sergipe (CAAE 38981320.2.0000.5546) with students from 10 to 18 years of age at a public school in a municipality in the Brazilian Northeast. A descriptive analysis of screen time, sociodemographic, economic variables, academic year, physical activity, sleep duration and daytime sleepiness was performed. Fisher's exact test and Pearson's chi-square test were used to analyze the independence hypothesis and the Mann-Whitney test to assess the hypothesis of equality of the median of two samples, in addition to simple and multiple logistic regression. Results : 364 students participated in the study. The eighth and ninth year of elementary school; the first and second years of high school made more excessive use of electronic devices. There is a greater chance of screen time higher than recommended in those with a higher socioeconomic level. High screen time was associated with the presence of daytime sleepiness, with a higher prevalence of excessive screen time in students who considered they rarely and often had sleepiness. Conclusions : The prevalence of excessive screen time was higher in adolescents considered older, when compared to younger ones and in those with better socioeconomic conditions. It is possible that screen time influences shorter sleep duration and the presence of daytime sleepiness.


Introduction
In the current scenario of globalization, modernization of technological means and changes in personal relationships and entertainment, the increase in screen time is notorious (Guedes et al., 2018). In Brazil, 93% of children and adolescents between 9 and 17 years old use cell phones (Centro Regional de Estudos para o Desenvolvimento da Sociedade da Informação, 2018). The Northeast was the region with the lowest prevalence of excessive screen time in teenagers (Schaan et al., 2019), in Sergipe, the prevalence of excessive television time was 70.9% for girls and 66.2% for boys aged 13 to 18 years old (Silva et al., 2014).
The transition from childhood to adolescence, there is a greater use of media and access by increasingly early ages, with the exception that this involvement depending on culture and behavioral traditions (Gonçalves et al., 2007;Schaan et al., 2019). A exposure to screen devices is considered the most sedentary behavior predominant with negative consequences on body composition, physical fitness, metabolic and cardiovascular risk factors, self-esteem, behavioral conduct, social behavior, length of sleep and academic performance (Schaan et al., 2019;Silva et al., 2014).
Given this situation and the increased prevalence of screen exposure among teenagers, it is relevant to analyze this habit in one of the regions that presented one of the lowest overuse rates. Therefore, the aim of this study was to understand the association of screen with eating behavior, physical activity, sleep and sociodemographic variables in adolescents in a city in Brazilian Northeast. Based on the results found, it would be possible to expand the literature data and establish interventions in an attempt to reduce the exposure time, to mitigate negative outcomes in adolescents.

Methodology
This is an observational, cross-sectional, quantitative, analytical study, approved by the Ethics Committee in Research on Human Beings of the Federal University of Sergipe (CAAE 38981320.2.0000.5546). The population is made up of 900 students, 250 of which are elementary school students and 750 high school students, enrolled in morning and afternoon shifts in urban public schools located in the Centro de Lagarto neighborhood in Sergipe.
To compose the sample of this research, adolescents aged between 10 and 18 years, enrolled in the selected educational institutions, regardless of sex, nutritional status, race or socioeconomic level, who attended morning or afternoon classes. Participants showed agreement with the research by signing the Free and Informed Assent Term (TALE) and obtained authorization of the person in charge, based on the Free and Informed Consent Term (TCLE). Those with some degree of intellectual disability that made it difficult to complete the questionnaire or with any type of physical disability that could interfere with screen use were excluded from the research.
Due to the current epidemiological scenario of the pandemic caused by the SARS-CoV 2 coronavirus agent, for data collection, researchers were present in schools during March to September 2021, so that TCLE was delivered to those responsible, they provided the TALE and the questionnaire to the student.
The semi-structured questionnaire with questions related to screen time was evaluated using the methodology The answers were analyzed from the weighted average of the time of use of each equipment in a week. Students who reported use equal to and/or greater than two hours per day, both for a specific device and for the sum of the total time, categorized as having excessive screen time (Eisenstein et al., 2019;Tremblay et al., 2011).
The sociodemographic variables were age in complete years, sex and grade/school year. The economic aspect was evaluated through the stratification of the Brazil Criterion, representing the order of purchasing power (Associação Brasileira de Empresas de Pesquisa, 2019).
In the evaluation of eating habits, the consumption of fruits and vegetables was analyzed based on the frequency of daily portions in a week (Grupo de Pesquisa em Estilos de Vida Saúde, 2016; Instituto Brasileiro de Geografia e Estatística, 2015). Students who reported consuming fruits and vegetables for five or more days in a week received the classification of adequate consumption. If consumption was lower, it was defined as inadequate (Instituto Brasileiro de Geografia e Estatística, 2015).
The level of physical activity was assessed of the GSHS questionnaire (Grupo de Pesquisa em Estilos de Vida Saúde, 2016; Instituto Brasileiro de Geografia e Estatística, 2015). Those who totaled a time greater than or equal to 60 minutes performing the questioned activities for at least five days were considered physically active. Responses with a shorter period, insufficiently active (Bull et al., 2020).
The questionnaire also addressed aspects of sleep in the last month. Regarding sleep duration, responses were categorized according to age into very short sleep, short sleep, recommended sleep, and long sleep (Galland et al., 2018). The subjective quality of sleep was established as very low, low, good or very good. Another item analyzed was the presence of daytime sleepiness (Munezawa et al., 2011).
Categorical variables (food, physical activity and sleep) were described using absolute frequency and percentage relative, the hypothesis of independence between variables was tested using Fisher's Exact and Pearson's Chi-Square. The continuous variables (screen time, sociodemographics and economic) were described as mean, median, standard deviation and interquartile range. The Mann-Whitney test was applied to evaluate the hypothesis of equality the median of two samples. Research, Society andDevelopment, v. 11, n. 15, e560111537671, 2022 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v11i15.37671 4 Gross and adjusted odds ratios and their respective confidence intervals through the simple and multiple logistic regression model. The inclusion of variables in the model required: hypothesis test with p-value less than 0.2, absence of separation phenomena (zero boxes) and percentage of absentees lower than 10%. The level of significance adopted was 5% and the software used was R Core Team 2021 (Version 4.1.0).

Results
The 364 students participated in the study, 204 from the middle school and 160 of elementary school II, aged between ten and eighteen years old. Between them, 64.3% (n=234) were female and 35.7% (n=130) were male and most classified their color as brown (56%), followed by white (29.7%), black (10.2%), yellow (3.0%) and indigenous (1.1%). The distribution of the students' economic classes were: A=1.9%, B1=8.0%, B2=23.9%, C1=21.2%, C2=27.5% and D and E=17.6%. Table 01 depicts the descriptive analysis according to age, points for class classification economic, classification of the total time of exposure to screens per week, eating behavior, physical activity, duration and quality of sleep.  Source: Authors. Table 2 depicts the relationship between excessive time and adequate screen use, defined from the evaluation of the average weight of use in a week, with the sociodemographic variables and independent. High screen time was associated with the presence of daytime sleepiness (p<0.05). In addition, the academic year, economic classification, number of hours of sleep per day and sleepiness daytime were included in the regression model presented in Table 3.

Discussion
The present study showed a high prevalence of excessive screen time in both sexes, highlighting the use of smartphones by more than half of the interviewees, which corroborates with Brazilian studies (Centro Regional de Estudos Exposure to screens for more than two hours a day was associated with higher socioeconomic status. Similar data were demonstrated in a study carried out in Brazilian, in which children with higher incomes were 3.5 times more likely to have more screen time, compared to the others (Nobre et al., 2021). It is possible that families with higher purchasing power facilitate access to different technologies considered leisure options and means of promoting learning, interaction and qualification (Nobre et al., 2021).
However, an inverse relationship was analyzed in Berlin, since adolescents with middle and low socioeconomic groups, showed a greater chance of excessive screen time compared to those belonging to the strata superiors of the economic classification, which were subjected to more restrictive rules regarding the use of screens for longer parenteral awareness of the harmful effects of exacerbated use (Tandon et al., 2012). It is worth remembering that Germany has a very high HDI, so the social support offered differentiates compared to the Brazilian Northeast, with an average HDI, a fact that may also influence the findings reported.
When comparing screen time between academic years, there was a greater chance of using higher than recommended for electronic devices by the ninth grade of elementary school II, first, second and third year of high school. Young people represent the target group of the entertainment market, which through technologies promote activation of the reward system, sudden escape from disturbing emotions, obtaining employment and income, in addition to the psychological and physical arousal that cause the craving to become compulsion (Guerrero et al., 2019;Riera et al., 2019). This, associated with the physiological characteristics of adolescence, favors the occurrence of behavioral and mood changes, less self-control, difficulty in interpersonal relationships, decreased academic performance, sleep problems and digital addiction (Hale & Guan, 2015;Twenge & Campbell, 2018).
Most participants reported having short sleep duration and high screen time associated with daytime sleepiness, especially among those who considered sleepiness rarely and frequente. Similarly, in Spain, using a allowed use of cell phone caused worse sleep quality (Riera et al., 2019). The delay in bedtime and the reduction in total sleep time were associated with the night period, which suggests the impact of the negative light of technological devices on sleep homeostasis (Hale & Guan, 2015).
The inverse relationship between screen time and sleep duration can compromise performance academic. It is observed that there is a reduction in the mechanisms necessary for brain maturation, daytime sleepiness, sleep problems, memory, lower psychological well-being and impact on stimulus processing and concentration (Guerrero et al., 2019;Hale & Guan, 2015;Instituto Brasileiro de Geografia e Estatística, 2015). Short sleep duration also may be associated with obesity and cardiometabolic risk factors due to circadian misalignment of the appetite, change in meal times and greater food consumption at night (Seo & Shim, 2019).
The high prevalence of inadequate food and the short time devoted to physical activity were verified in adolescents with excessive use of screens (Instituto Brasileiro de Geografia e Estatística, 2015; Silva et al., 2014). However, in this study, use of screens was not associated with dietary habits and activity physical, appear to be independent factors.
It is important to address the limitations of this study. For data collection, we used self-report questionnaire, which allows for greater detailing of the data and is a form used in epidemiological studies. However, accuracy can be compromised when using the method recall and by questioning socioeconomic data and health risk behaviors, which may stimulate change in response to what actually occurs. As this is an extensive questionnaire, it may have had less careful reading and unreliable answers. The questionnaire did not show the alternative "does not have", when questioned about the use of each electronic device, a fact that differs from do not use. In addition, as it is a cross-sectional study, it is not possible to confirm the relationships of cause and effect found, with only associations being suggested. The study sample is not representative of all teenagers in the city and did not include students from rural schools, however, it encompassed schools with the highest number of students from elementary school II and high school. Finally, the study was carried out during the coronavirus pandemic, a period in which confinement may have interfered in the increase in sedentary behaviors and in encouraging the use of screens for longer prolonged than usual, which perhaps did not reflect the habits prior to that event.

Conclusion
In conclusion, in this study, there was a high prevalence of excess screen time, especially in those with older age in the sample and with better socioeconomic conditions. The findings suggest an influence of screen use on sleep quality by verifying a correlation with shorter sleep duration and daytime sleepiness, which culminates in an unhealthy and inappropriate lifestyle for the physiological development. Thus, public health authorities in partnership with the schools could, from these data, develop interventions aimed at health education in the attempt to reduce the time exposed and the negative outcomes of this habit. Finally, longitudinal studies and more research with similar and more comprehensive methodological procedures in other schools and cities become necessary in order to confirm the results in the Brazilian context.