Simultaneous oral health risk behaviors among adolescents : evidence from the National School-based Student Health Survey

Rev BRas epidemiol 2018; 21(sUppl 1): e180019.sUpl.1 RESUMO: Objetivo: Identificar a prevalência da presença simultânea de comportamentos de risco à saúde bucal em adolescentes brasileiros e fatores associados. Métodos: Foram utilizados dados de 109.104 escolares provenientes da Pesquisa Nacional de Saúde do Escolar (PeNSE). A presença simultânea de baixa frequência de escovação dentária (E), uso recente de cigarros (C), baixa frequência de ida ao dentista (D), baixo consumo de frutas (F) e alto consumo de alimentos que contêm açúcar adicionado (A) foi avaliada pela razão entre as prevalências observada e esperada (PO/PE). Regressão logística foi utilizada para avaliar a associação entre as combinações de comportamentos e as variáveis sociodemográficas e do contexto familiar. Resultados: A ocorrência de dois ou mais comportamentos de risco à saúde bucal foi de 60,40%. As combinações mais prevalentes com razão PO/PE acima de 1,20 foram EDF, CFA e EDFA. A chance de concentrar dois ou mais comportamentos foi maior para adolescentes sem supervisão familiar dos deveres de casa, de escolas públicas, do sexo masculino e das raças indígena ou amarela (odds ratio — OR > 1,00; p < 0,05). O nível de afluência familiar baixo atuou como risco para a combinação ECDFA (OR = 2,58; p = 0,009), enquanto para a combinação CFA os níveis médio e baixo atuaram como proteção (OR = 0,71; p < 0,001 e OR = 0,76; p = 0,011). Conclusão: A prevalência da presença simultânea de comportamentos de risco à saúde bucal foi baixa e associada negativamente a fatores sociodemográficos e do contexto familiar. Intervenções que busquem reduzir os comportamentos de risco em saúde bucal em adolescentes devem priorizar os grupos identificados.

Simultaneous oral health risk behaviors among adolescents: evidence from the National School-based Student Health Survey

INTRODUCTION
Health behaviors play an important role in determining and preventing chronic noncommunicable diseases (CNCDs).Unhealthy diet, smoking, lack of physical activity and excessive use of alcohol are recognized as behavior of risk for morbidity and mortality 1 .Similarly, inadequate behaviors establish an inverse relationship with oral health status 2 .The main behaviors related to oral health include eating habits, oral hygiene practices and smoking 2 .
Adolescence is a crucial period for the promotion and establishment of habits, marked by gains in autonomy, transition between social roles and new experiences 3 .Health risk behaviors tend to start at this stage of life and continue into adulthood 4,5 .In Brazil, the increase in school adolescents with nonfrequent dental brushing between 2009 and 2012 have drawn attention 6 , an attitude that may lead to the accumulation of dental biofilm throughout life and, consequently, to a higher risk of developing chronic oral diseases such as cavities and periodontal diseases 7 .
Health risk behaviors in individuals do not occur in isolation: they tend to add to others 8 .Protection factors for oral health risk behaviors usually correspond to behaviors and patterns related to general health: being a female and having better socioeconomic level, for adults and adolescents [9][10][11][12][13][14] ; parents with higher educational levels, 15 and more family support for adolescents 11,12,16 .

Palavras-chave:
As part of surveillance actions for CNCDs, Brazil has conducted, since 2009, the National School Health Survey (PeNSE), which investigates the health risk and protection factors among Brazilian school adolescents.A previous study grouped behaviors related to general health using the database of the survey, but oral health variables were not analyzed 14 .Considering the approach to common risk factors for chronic diseases, part of the variables investigated also pose risk to the leading oral health problems, including diet, smoking and alcohol consumption 2 .However, there are behavioral factors that, combined with others, influence oral health specifically, such as toothbrushing frequency and visits to a dentist.
The present study sought to assess simultaneous behaviors related to oral health based on PeNSE data, also including those related to general health.When considering socio-demographic characteristics and family context, we sought to identify the groups of Brazilian adolescents who are vulnerable to multiple behaviors posing risk to oral health.The results could support the creation of integrated public policies to prevent multiple oral health risk behaviors, 22 with a view to reducing the burden of oral diseases, as well as the social and economic costs of treatment for adolescents across the country.
Therefore, the objective of this study was to investigate the simultaneous presence of oral health risk behaviors among Brazilian school adolescents and their association with sociodemographic factors and familial context in a sample of national representation.

METHODS
Cross-sectional study using data from PeNSE 2012.Access to this database is available on the website of the Brazilian Institute of Geography and Statistics (IBGE) in the current year.

METHODOLOGICAL ASPECTS OF PENSE 2012
PeNSE is a partnership between the Ministry of Health, IBGE and the Ministry of Education.The study population was made up of students attending the 9th year of elementary education in public and private schools of the 26 Brazilian State capitals, the Federal District and other municipalities in the five major regions of the country.
The survey was carried out in school environment for ease of access to schoolchildren, since most of the population aged 6 to 14 (98.20%) was enrolled in schools in 2011 23 .Of these, 85.6% were attending public schools and 14.4%, private schools.
Rev BRas epidemiol 2018; 21(sUppl 1): e180019.sUpl.1 The sample was estimated based on School Census 2010, excluding schools with less than 15 students in the grades chosen and night-shift classes.The choice for the 9th year is justified by the minimum schooling level needed to answer a self-administered questionnaire and the proximity to the reference age range recommended by the World Health Organization (WHO), which is 13 to 15 years.
The sampling process used a two-phase probabilistic method by cluster selection for the capitals: schools (primary units) and eligible classes in schools selected (secondary units); and three phases for non-capitals: groups of municipalities (primary units), schools (secondary units) and eligible classes in schools selected (tertiary units).All students present on the day of questionnaire application were invited to participate.
The sample size was estimated based on the following parameters: maximum relative error of 3 percentage points, 95% confidence interval (95%CI) and prevalence of 50.00% for the various situations that contemplate adolescent health.The sample size to test the associations between variables was evaluated and shown sufficient.Sample weights were calculated so that data collected could represent all students enrolled in the 9th grade who regularly attended classes in daytime period at public and private schools.Weights were obtained considering absences on the day of questionnaire application and students who did not give an answer to the variable "gender".
For data collection, a self-administered structured questionnaire (made available in a smartphone) was used, which included topics such as feeding habits, physical activity, smoking, alcohol and drugs consumption, oral health, violence and accidents, among others, based on Global Youth Risk Behavior Surveillance System 24 .Additional information on methodological aspects of PeNSE is available elsewhere 25 .
In total, 109,104 adolescents from 2,842 schools agreed to participate.The response rate was 82.60%.

ETHICAL ASPECTS
PeNSE 2012 was approved by the National Research Ethics Committee (CONEP) of Ministry of Health.Participation by students was voluntary and conditioned to their signing an informed consent form.

VARIABLES ANALYZED
The following questions and respective categories, encompassing oral health-related behaviors, were extracted from the PeNSE questionnaire: • Frequency of tooth brushing: "In the past 30 days, how many times per day did you usually brush your teeth?" (less than twice and twice or more times a day) 26 ; • Recent use of cigarettes: "In the past 30 days, on how many days did you smoke cigarettes?" (one or more days and never) 26 ; • Visits to the dentist: "In the past 12 months, how many times did you go to the dentist?" (once or more and not once) 12 ; • Weekly fruit consumption: "In the past 7 days, on how many days did you eat fresh fruit or fruit salad?" (low consumption: none to four days, and high consumption: at least five days a week) 27 ; • Two questions addressing weekly consumption of foods containing added sugar: "In the past 7 days, on how many days did you eat treats (sweets, candies, chocolates, chewing gum, or lollipops)?" and "In the past 7 days, on how many days did you have soda?".Responses were categorized as: low consumption (none to four days) and high consumption (five or more days), characterizing the intake of snacks or soft drinks at least five days a week 28 .
FAL was calculated from information on the possession of goods and services (landline, cell phones, computer, internet at home, car, motorcycle, number of bathrooms with shower and domestic employee service in the household).Each good/service scored 1 per positive response, or 0 for negative, except for the number of bathrooms containing shower reported, which received the corresponding value (0-4).Scores were summed to generate one per participant.This score was classified according to the criteria recommended in the family affluence scale, with three categories, where 0-3 indicates low level; 4-5 medium or moderate level, and 6 or more, high level 29 .
Family supervision was assessed by the question: "In the past 30 days, how often did your parents/guardians check to see if your homework was done?"The answers were categorized in: never or rarely and yes (sometimes, most of the time and always) 30 .

DATA ANALYSIS
A descriptive analysis of independent variables (sociodemographic and family context) of participants and oral health risk behaviors was carried out.Each behavior was categorized as 0 = healthy behavior or 1 = risk behavior, as per previous studies 12,26,28 .
The number of possible combinations for oral health risk behaviors was 32 (2 5 ).Simultaneity of risk behaviors for oral health was evaluated by the ratio between observed and expected prevalence (OP/EP).OP was given by the sample, and EP was calculated by multiplying the individual probabilities of presenting each behavior, assuming that they occur independently.
Descriptive analyses of different combinations of behaviors in relation to the independent variables revealed small number of schoolchildren under the age of 13 presenting combinations.Therefore, we chose not to include the variable age in the models.The collinearity between independent variables was tested by a correlation matrix.Correlations between variables ranged from weak to moderate (from 0.10 to 0.50) 31 , exception mother's and father's educational level (r = 0.56).Thus, the variable father's education was not included in regression.
Logistic regressions (simple and multiple) were used to test associations between each combination of behaviors (variable outcome) and independent variables.Only combinations with OP/EP ratio greater than 1.20 were included in the models 32,33 .
To identify the variables associated with each outcome variable, odds ratio (OR) and 95%CI were used as an effect measure, obtained by logistic regression analysis.All variables with significance level less than 0.20 in the bivariate analysis were included in adjusted models.The multiple logistic regression analysis was based on models that included all pre-selected independent variables, and the variables with p>0.05 were removed step by step.
In all analyses, the sample design effect for complex samples was beared in mind and the svy command of the statistical program Stata 13.0 (Stata Corp., College Station, USA) was applied.The quality of model adjustment was evaluated by appropriate tests, by using Stata's estat gof command.

RESULTS
The sociodemographic profile of participants and the prevalence of behaviors are shown in Table 1.The sample consisted mainly of adolescents aged 13 to 15 (86.03%), females (52.16%) and enrolled in public schools (82.83%).Brown color/ethnicity was majority in the sample (42.22%) and mother's and father's schooling level was predominantly low (42.24 and 43.54%, respectively).The most frequent FAL was high (40.50%)and most participants had family supervision for homework (56.37%).
Prevalence values of oral health risk behaviors among adolescents was: 8.68% for low toothbrushing frequency, 5.07% for recent cigarette use, 36.39% for low frequency of visits to the dentist, 30.21% for low fruit consumption, and 55.28% for high consumption of foods with added sugar.
Of all participants, 32.40% had only 1 oral health risk behavior, 41.40% had 2 behaviors, 16.50% had 3 behaviors, 2.4% had 4 behaviors, and 0.10% had 5 combined behaviors.About 7% did not present any of the risk behaviors investigated.
Ten combinations of behaviors had OP/EP higher than 1.20, which characterizes simultaneity (Table 2): ECDFA, ECDF, ECDA, EDFA, ECA, ECF, EDF, CFA, ED and CA; where E refers to the low toothbrushing frequency, C to recent use of cigarettes, D to low frequency of visits to the dentist, F to low consumption of fruits, and A to high consumption of foods with added sugar.ECDA combination had the highest OP/EP ratio.Table 3 displays the results of the multiple logistic regression analysis for the seven final models presenting good adjustment quality (p>0.05).Family supervision maintained its effect in all models (p<0.01).School network and gender maintained their significance in five and two models, respectively, wherein male adolescents enrolled in public schools were more likely to present the combinations.Skin color/ethnicity maintained its significance in two models: ECA, with Asian ethnicity exhibiting greater chance (OR = 3.05, p < 0.05), and greater chance of CA among individuals of Indigenous background (OR = 1.87, p <0.05).On the other hand, low FAL kept its higher probability of behaviors in one model (ECDFA), while mean and low FAL values acted as protective factors for CFA (OR = 0.71, p <0.001 and OR = 0.76, p <0.05, respectively).Association with mother's schooling was not maintained in the adjusted model.

DISCUSSION
This study brings innovations while analyzing the simultaneous presence of oral health risk behaviors among adolescents in a sample representative of the country, its State capitals and five major regions.The main findings are: high prevalence of risk behaviors studied, the low prevalence of simultaneous behaviors, and the identification of vulnerable groups presenting simultaneous behaviors (adolescents without family supervision, enrolled in public schools, both males and females, with Indigenous or Asian ethnic background).
Rev BRas epidemiol 2018; 21(sUppl 1): e180019.sUpl.1 Another highlight is the inclusion of an unexplored variable as related to grouping of oral health risk behaviors by adolescents from countries outside the Western Europe-United States axis: family supervision of homework.When considering family supervision as a set of parental behaviors involving attention to the tracking of activities, places the adolescent goes to, and processes of children adaptation 34 , the variable homework supervision is part of this set of positive parental practices 35 .This study reports a consistent association between lack of family supervision for homework and a greater chance of combining oral health risk behaviors, corroborating previous findings with positive association between more family supervision and less involvement of European and American adolescents in two or more health risk behaviors 11,36 .
A highlight of the study is that, although the low frequency of toothbrushing and recent cigarette use had the lowest prevalence in the sample, these behaviors were the most frequent when combinations with OP/EP ratio were observed above that expected at random.For most combinations, the low frequency of toothbrushing was alongside less frequent visits to the dentist, while the recent use of cigarettes was combined with high consumption of foods with added sugar.These are worrisome results, since a high-sugar diet is known to be a risk factor for dental cavities, diabetes, obesity and cardiovascular diseases, while smoking contributes to several types of cancer, periodontal diseases and oral mucosa lesions 2 .
Similar prevalence values for low toothbrushing and low fruit consumption have been reported among Danish adolescents 37 .Such findings suggest that oral health promotion interventions may benefit from an approach that can join these behaviors.
It is important to note that the combination of recent cigarette use, low fruit consumption and high consumption of foods with added sugar was less pronounced in adolescents of low and mean FAL.These results seem to suggest that higher economic resources may facilitate access to industrialized products such as cigarettes and foods with high sugar content, as observed by Mistry et al. 36 in the United States and by Gonçalves et al. 38 in Brazil, indicating the need for family monitoring when it comes to access to such items.
Studies have shown that male adolescents are more likely to adopt a number of unhealthy behaviors, such as less frequent toothbrushing 6,12 , cigarette use 39 and less regular visits to the dentist 39 .When analyzing behavior combinations in our study, the male risk effect was maintained for two combinations, confirming the need for specific strategies that engage this audience in healthier lifestyle habits.
Because this was a cross-sectional study, it was not possible to make causal inferences about the factors studied.As the instrument for data collection was a questionnaire, likely information bias is related to social desirability, meaning that answers to some of the questions may have been under-or over-reported.However, self-reported behaviors in adolescents have validity 40 and the guarantee of anonymity in this questionnaire can minimize this tendency.Another type of information bias is memory, which is present in questions that require referring to longer time cuts, such as dentist visits in the year prior to survey.
PeNSE is consolidated as a tool to monitor the health of Brazilian school adolescents, and its continuity is of utmost importance.Its instrument of data collection has been improved: the 2015 edition was added with questions related to the use of electronic cigarette and daily consumption of certain foods.As for oral health, additional questions addressing self-perception, the impact of oral health conditions on daily performance, and reasons for the last visit to the dentist are encouraged.It is recommended that strategies aimed at collecting health information from out-of-school adolescents be outlined.
The present study steps forward by identifying the factors associated with simultaneity of multiple oral health risk behaviors among adolescents, pointing to determinants that are common to risk behaviors for chronic diseases.The approach of common risk factors in intersectoral interventions involving the family, the school and social contexts of adolescents should be privileged, as it offers opportunities for an integrated tackling of challenges and the empowerment of adolescents.

CONCLUSION
The prevalence of simultaneous oral health risk behaviors was low, although associated with sociodemographic factors and familial context.Adolescents without family supervision for homework, enrolled in public schools, males, and of Indigenous or Asian ethnicity were more likely to present two or more behaviors combined.
Family supervision is highlighted as a protective factor for multiple oral health risk behaviors, which adds evidence to the importance of family's role in adolescents' health-related choices.Interventions aimed to reduce oral health risk behaviors among adolescents should prioritize the vulnerable groups identified.

Table 1 .
Socio-demographic characteristics of participants and prevalence of oral health risk behaviors (n = 109,104).National School Health Survey, Brazil.
*Corrected for the sample design; **family affluence level: land line, cell phone, computer, home internet, car, and motorcycle ownership; number of bathrooms with shower and existence of domestic service employee in the household.Table 1.Continuation.

Table 2 .
Prevalence of combined oral health risk behaviors.National School Health Survey, Brazil.
E: low frequency of tooth brushing; C: recent use of cigarettes; D: low frequency of visits to the dentist; F: low fruit consumption; A: high consumption of foods with added sugar; OP: observed prevalence; EP: expected prevalence; OP/EP: ratio observed/expected prevalence; + presence of risk behavior; -absence of risk behavior; OP/EP > 1.20.

Table 3 .
Result of the multiple logistic regression between combined oral health risk behaviors and independent variables.National School Health Survey, Brazil.: low frequency of tooth brushing; C: recent use of cigarettes; D: low frequency of visits to the dentist; F: low fruit consumption; A: high consumption of foods with added sugar; OR: adjusted odds ratio.95%CI: 95% confidence interval; ref.: reference category; *p <0.05; FAL: family affluence level.