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Factors associated with heavy alcohol use among students in Brazilian capitals

Abstracts

OBJECTIVE: To evaluate the association between heavy use of alcohol among students and family, personal and social factors. METHODS: Cross-sectional study including public school students aged ten to 18 from 27 Brazilian capital cities in 2004. Data was collected using an anonymous, self-report questionnaire that was adapted from a World Health Organization instrument. A representative sample comprising 48,155 students was stratified by census tracts and clusters (schools). The associations between heavy alcohol use and the factors studied were analyzed using logistic regression at a 5% significance level. RESULTS: Of all students, 4,286 (8.9%) reported heavy alcohol use in the month prior to the interview. The logistic regression analysis showed an association between fair or poor relationship with the father (OR = 1.46) and the mother (OR = 1.61) and heavy use of alcohol. Following a religion (OR = 0.83) was inversely associated with heavy alcohol consumption. Sports practice and mother perceived as a "liberal" person had no significance in the model. However, a higher prevalence of heavy use of alcohol was seen among working students. CONCLUSIONS: Stronger family ties and religion may help preventing alcohol abuse among students.

Students; Alcohol Drinking; Family Characteristics; Socioeconomic Factors; Cross-Sectional Studies


OBJETIVO: Analisar a associação entre o uso pesado de álcool entre estudantes e os fatores familiares, pessoais e sociais. MÉTODOS: Estudo transversal realizado com estudantes de dez a 18 anos de escolas públicas de 27 capitais brasileiras, em 2004. Os dados foram coletados por meio de questionário anônimo, de autopreenchimento, adaptado de instrumento desenvolvido pela Organização Mundial da Saúde. A amostra representativa, composta por 48.155 estudantes, foi estratificada por setores censitários e por conglomerados (escolas). Associações entre o uso pesado de álcool e os fatores estudados foram analisadas por meio de regressão logística, considerando nível de significância de 5%. RESULTADOS: Do total de estudantes, 4.286 (8,9%) fizeram uso pesado de álcool no mês anterior à entrevista. A análise por regressão logística mostrou associação entre relações ruins ou regulares com pai (OR=1,46) e mãe (OR=1,61) e uso pesado de álcool. Seguir uma religião (OR=0,83) mostrou-se inversamente associado a este tipo de consumo de álcool. A prática de esportes e o fato de a mãe se percebida como liberal não mostraram significância no modelo. Houve maior prevalência de uso pesado de álcool entre os estudantes que trabalhavam. CONCLUSÕES: Ligações familiares mais coesas e seguir uma religião podem prevenir o uso abusivo de álcool entre estudantes.

Estudantes; Consumo de Bebidas Alcoólicas; Características da Família; Fatores Socioeconômicos; Estudos Transversais


OBJETIVO: Analizar la asociación entre el uso pesado de alcohol entre estudiantes y los factores familiares, personales y sociales. MÉTODOS: Estudio transversal realizado con estudiantes de diez a 18 años de escuelas públicas de 27 capitales brasileras, en 2004. Los datos fueron colectados por medio de cuestionario anónimo, de auto-completación, adaptado de instrumento desarrollado por la Organización Mundial de la Salud. La muestra representativa, compuesta por 48.155 estudiantes, fue estratificada por sectores censitarios y por conglomerados (escuelas). Asociaciones entre el uso pesado de alcohol y los factores estudiados fueron analizadas por medio de regresión logística, considerando nivel de significancia de 5%. RESULTADOS: Del total de estudiantes, 4.286 (8,9%) hicieron uso pesado de alcohol en el mes anterior a la entrevista. El análisis por regresión logística mostró asociación entre relaciones malas o regulares con padre (OR= 1,46) y madre (OR =1,61) y uso pesado de alcohol. Seguir una religión (OR=0,83) se mostró inversamente asociado a este tipo de consumo de alcohol. La práctica de deportes y el hecho de que la madre se perciba como liberal, no mostraron significancia en el modelo. Hubo mayor prevalencia del uso pesado de alcohol entre los estudiantes que trabajaban. CONCLUSIONES: Uniones familiares más coherentes y seguir una religión pueden prevenir el uso abusivo de alcohol entre estudiantes.

Estudiantes; Consumo de Bebidas Alcohólicas; Composición Familiar; Factores Socioeconómicos; Estudios Transversales


ORIGINAL ARTICLES

José Carlos F GaldurózI; Zila van der Meer SanchezII; Emérita Sátiro OpaleyeII; Ana Regina NotoI,II; Arilton Martins FonsecaII; Paulo Leonardo Sirimarco GomesIII; Elisaldo Araújo CarliniII

IDepartamento de Psicobiologia. Universidade Federal de São Paulo (Unifesp). São Paulo, SP, Brasil

IICentro Brasileiro de Informação sobre Drogas Psicotrópicas. Departamento de Psicobiologia. Unifesp. São Paulo, SP, Brasil

IIIRecuperadora Nacional de Crédito. São Paulo, SP, Brasil

Correspondence

ABSTRACT

OBJECTIVE: To evaluate the association between heavy use of alcohol among students and family, personal and social factors.

METHODS: Cross-sectional study including public school students aged 10 to 18 from 27 Brazilian capital cities in 2004. Data was collected using an anonymous, self-report questionnaire that was adapted from a World Health Organization instrument. A representative sample comprising 48,155 students was stratified by census tracts and clusters (schools). The associations between heavy alcohol use and the factors studied were analyzed using logistic regression at a 5% significance level.

RESULTS: Of all students, 4,286 (8.9%) reported heavy alcohol use in the month prior to the interview. The logistic regression analysis showed an association between fair or poor relationship with the father (OR = 1.46) and the mother (OR = 1.61) and heavy use of alcohol. Following a religion (OR = 0.83) was inversely associated with heavy alcohol consumption. Sports practice and mother perceived as a "liberal" person had no significance in the model. However, a higher prevalence of heavy use of alcohol was seen among working students.

CONCLUSIONS: Stronger family ties and religion may help preventing alcohol abuse among students.

Descriptors: Students. Alcohol Drinking. Family Characteristics. Socioeconomic Factors. Cross-Sectional Studies.

RESUMEN

OBJETIVO: Analizar la asociación entre el uso pesado de alcohol entre estudiantes y los factores familiares, personales y sociales.

MÉTODOS: Estudio transversal realizado con estudiantes de diez a 18 años de escuelas públicas de 27 capitales brasileras, en 2004. Los datos fueron colectados por medio de cuestionario anónimo, de auto-completación, adaptado de instrumento desarrollado por la Organización Mundial de la Salud. La muestra representativa, compuesta por 48.155 estudiantes, fue estratificada por sectores censitarios y por conglomerados (escuelas). Asociaciones entre el uso pesado de alcohol y los factores estudiados fueron analizadas por medio de regresión logística, considerando nivel de significancia de 5%.

RESULTADOS: Del total de estudiantes, 4.286 (8,9%) hicieron uso pesado de alcohol en el mes anterior a la entrevista. El análisis por regresión logística mostró asociación entre relaciones malas o regulares con padre (OR= 1,46) y madre (OR =1,61) y uso pesado de alcohol. Seguir una religión (OR=0,83) se mostró inversamente asociado a este tipo de consumo de alcohol. La práctica de deportes y el hecho de que la madre se perciba como liberal, no mostraron significancia en el modelo. Hubo mayor prevalencia del uso pesado de alcohol entre los estudiantes que trabajaban.

CONCLUSIONES: Uniones familiares más coherentes y seguir una religión pueden prevenir el uso abusivo de alcohol entre estudiantes.

Descriptores: Estudiantes. Consumo de Bebidas Alcohólicas. Composición Familiar. Factores Socioeconómicos. Estudios Transversales.

INTRODUCTION

The first exposure to alcohol often occurs during childhood and adolescence, the latter being a life phase marked by social and psychological vulnerability. It is characterized by search for new experiences, along with impulsive behaviors, anxiety, insecurity, dissatisfaction and aggression.4 Alcohol use meets all the requirements for the disharmony in adolescence: immediate pleasure; transgression; escape through solitary pleasure; playing with death; need for power; nonconformity; need for freedom, acceptance and respect from peers/friends.3

While most teenagers try alcohol, a small proportion may develop abuse with serious consequences for their future life.21 Studies have showed that early use of alcohol is one of the main factors for heavy drinking in the future.27 In Brazil, although prohibited by law, young people can easily obtain alcohol, which has wide cultural acceptance across all socioeconomic classes.19

Besides adolescents' vulnerability and easy access to alcohol, other associated factors have been studied, such as family relationships. Studies have reported that increased use of substances by children is associated with parents who have little control over them, or do not care about their habits, as well as with lack of communication between parents and children. Personal and social factors such as not practicing a religion, low compliance with school activities, and pressure from peers who use drugs are also concurrent with substance abuse.9

Other factors such as work and sports may be associated with the use or non-use of substances. Adolescents who work are more prone to substance use. Some authors suggest that this behavior is due to contact with adults in the workplace, stress, low school commitment, and increased income, all of which allow greater substance use and early transition to adult roles.24

Although sports are associated with healthy behaviors, evidence points to a controversy when it comes to alcohol. Some studies indicate sports as a protective factor, while others found no association. Most of them, however, show a positive correlation between alcohol and sports.16

Therefore, having a better understanding of factors associated with substance use among adolescents can be a valuable input for researchers to design preventive actions and interventions on these behaviors.23 Since alcohol consumption is socially accepted, its use needs to be further explored among young people to prevent a potential progression to abuse.

The objective of the present study was to evaluate heavy use of alcohol among students and its association with family, personal and social factors.

METHODS

A cross-sectional study was conducted among students aged ten to 18 years from public elementary and high schools in all Brazilian capitals. A representative sample was stratified by census tracts in each city and their related socioeconomic characteristics, as well as by clusters corresponding to the schools selected. Random selection was carried out in two stages: first by school, and then by classroom, as proposed by Kish.12

Data were collected through an anonymous self-administered questionnaire with closed questions, adapted from an instrument of the World Health Organization (WHO).22 The instrument was applied between April and June 2004. The questionnaire was administered to all students in the classroom, in the absence of the teacher to reduce bias towards underreporting. Each classroom was visited only once when researchers, who had been properly trained, explained the objectives of the study to students. To ensure anonymity, students were asked to drop their questionnaires inside a box after completion. The questionnaire comprised questions about frequency and pattern of substance use; demographic data; school attendance; sports; religion and work. In addition, there were questions about family relationships and perception of parental control. The instrument had a socioeconomic scale developed by the Brazilian Association of Market Research Institutes. In order to increase the reliability of responses, we included a question on the use of a fictitious drug in the questionnaire.

We adopted some procedures to detect and correct typing errors, e.g. answers with impossible values. In addition, a subsample comprising 10% of subjects in each city was drawn for a full check of the questionnaire. Typing errors accounted for less than 2% of all 2,166,975 pieces of data entered. Since each question consisted of several items, it allowed us to test internal consistency. For example, if a student checked "use over the year" but not "lifetime use," it was considered an inconsistency and the data was excluded.

Questionnaires with typing errors were corrected and inconsistencies were manually reviewed. Those questionnaires with a "yes" answer to the question on the fictitious drug or with more than three cancelled questions or blank answers were excluded from the sample. The final sample included 48,155 students as shown in Table 1.

Heavy alcohol users were those students who consumed alcohol for 20 days or more in the last month or had at least six episodes of alcohol intoxication during the same period. Out of the total sample, 4,286 students (8.9%) were classified as heavy alcohol users.

We applied weights to the distribution in the sample, allowing expansion of data to the target population. The expansion fraction is calculated by dividing the total number of classrooms by the number of schools in the sample, assuming that each student has an equal probability of being included in the sample.12

The study database was divided into two parts: one with 70% of the records (development database) used for estimating the logistic regression parameters, and the other one with the remaining 30%, used to validate the model (validation database). The validation consisted of a statistical assessment of the difference between the receiver operating characteristic (ROC) curve estimates of the two sub-samples.

First, as a preliminary analysis, we performed the bivariate analysis at the level of significance of 20% in order to separate the variables that would be modeled by logistic regression, for which we considered a level of significance of 5%. All procedures for logistic regression and validation of the model followed the guidelines proposed by Hosmer & Lemeshow.10 The variables of interest included: gender; age; relationship with the father and the mother; relationship between parents; perception of parental control; school delay; religion; sports; and work. For the analyses we used the public domain software R (R Project for Statistical Computing).

Subjects were informed their participation in this study was voluntary and that they were free to withdraw their participation at any time or leave questions unanswered. The informed consent form was signed only by the schools' principals. The Research Ethics Committee of Universidade Federal de São Paulo approved the study (0718/03).

RESULTS

In the bivariate analysis, all variables were significant at 80% confidence interval.

Table 2 presents the results from the final logistic regression model (p-values, odds ratios and confidence interval) at 5% significance level.

Students who were most likely to report heavy alcohol use: were older than 15 years; had fair or poor relationship with both parents; had divorced parents; perceived the father as a liberal person; had no religious affiliation; and had a formal job.

Considering the most significant p-values (p<0.001) and odds ratios (OR) that were the farthest from 1.0, factors associated with heavy use of alcohol in the month preceding the survey were: formal work (OR = 1.84), age over 15 years (OR = 1.75) and fair or poor relationship with the mother (OR = 1.61).

Formal work appears as the variable most strongly associated with heavy alcohol use among adolescents. Students who had a formal job were 84% more likely to report heavy use of alcohol compared to those without formal employment.

Sports practice and the perception of having a liberal mother did not show any statistical significance and were disregarded. The perception of a liberal father was associated with heavy use of alcohol among students (OR = 0.87, p = 0.01).

However, among family-related variables, the father-child relationship rather than the student's perception of his/her father as a liberal person had a stronger association with the outcome. Having a fair or poor relationship with the mother increased by 61% the likelihood of an adolescent to report heavy alcohol use. The same was seen among those with a negative relationship with the father, though with less strength (likelihood increased by 46%). In this model, those who followed a religion were 17% less likely to report heavy use of alcohol considering the other variables used for constructing the model.

The statistical comparison of the ROC curve estimates between the development and validation databases showed no statistical difference between the two ROC curves assessed (p = 0.76).

DISCUSSION

Self-administered questionnaire in the classroom is the most widely used method to assess the prevalence of substance use among students due to its better cost-benefit relation, low rates of refusal and assurance of anonymity.22 However, it has some limitations. First, the assessment in the classroom may exclude school dropouts or those students who were absent on the day of the interview since they can be often absent or have serious problems due to substance use. Furthermore, the responses were reports of drug use rather than measures of consumption, which may have led to underreporting of actual cases for students' fear of providing information, or over-reporting due to students providing false information.

Similarly, the results cannot be extrapolated to the reality of students in private schools in Brazil, because the sample is representative only of the student population of public schools.

Brazilians are culturally permissive toward alcohol use, and its advertising is much appreciated for its quality and creativity. Adolescents and young adults are particularly exposed to alcohol, and they are even a target population.17 In Brazil the legal age to consume alcohol is 18, but this law is not effectively enforced and underage adolescents can easily buy alcohol.13

Adolescents who consume alcohol may have several negative consequences, from social and school problems to more serious behaviors such as unprotected and/or non-consenting sex, increased risk of suicide or homicide and alcohol-related injuries.8 To that regard, many studies have investigated factors associated with alcohol and other drug use in this age group.18 The finding of 8.9% of adolescents reporting heavy use of alcohol during the month preceding the survey in a representative sample of public school students from capital cities may be indicative of a serious public health issue.

Studies in adults have showed males are more prone to heavy use of alcohol and they also have greater consequences due to its use while women suffer more from violence related to alcohol consumption.ª The data in the present study indicate slight gender differences. Boys were 10% more likely to report heavy alcohol use than girls. Yet recent data from an epidemiological survey among American students did not find any significant differences in heavy alcohol consumption between males and females.6

Factors related to family structure and relationships have been extensively studied in association with alcohol.5 The present study showed that heavy alcohol use was strongly associated with having a poor relationship with either the father or the mother, perception of the father as a liberal person and divorced parents, which corroborates other studies.26 However, the association between the parent-child relationship and heavy alcohol consumption was stronger among those whose parents apparently were liberal, suggesting that the quality of the relationship should more strongly considered in the context of behaviors that aim at monitoring the adolescent. Perceiving parents as liberal can be a way of masking relationships characterized by misunderstanding, rejection or abandonment.26

Consistent with other studies,25 belonging to a religion was negatively associated with greater consumption of alcohol among adolescents and young people. The mechanisms involved are not clear yet, and this finding may be attributed to the public aspects of religion, such as participation in religious groups,1 or to the private domain, such as individual prayer and the importance given to religion.15 One of the few qualitative studies on the subject confirms the quantitative findings, indicating that the major difference between drug users and non-users among low-income Brazilian adolescents was their religiosity and their family's. The authors also found that 81% of non-drug users practiced a religion of their own free will and out of admiration, and that only 13% of drug users did the same.20

Lorente et al14 (2004) reported a positive relationship between alcohol use and sports practice among French students that was even more evident among those who practiced team sports. Similarly, Eitler et al7 (2003) found a stronger association between alcohol use and students who played soccer. In our study, however, sports practice was not associated with heavy alcohol use among adolescents. One possible explanation could be a narrow interpretation of the question as students may have considered physical education, which is compulsory in schools, "sports practice" given the high number of positive answers to this question.

However, despite the positive association between sports activities and alcohol use, this relationship seems to vary depending on factors such as skin color, gender, identity, type of sports, number of participants and regular extracurricular activity.16 Thus, more in-depth studies are required to further explore this subject, preferably with a qualitative design.

Heavy use of alcohol was higher among students who worked than those who did not. This is not a consensus in the literature. Some studies have postulated that adolescents who do not work are more inclined to spend their free time consuming alcohol and other drugs,2 while others claim that work is a risk factor for substance use among adolescents.11

In the present study, work was the factor most strongly associated with heavy alcohol use, followed by age over 15 years. Greater access to alcoholic beverages due to their own income is possibly one of the factors involved in greater heavy alcohol use among working adolescents. Another reason would be exposure to an environment outside the family, which together with taking on an adult role, would promote their early independence and lack of parental supervision, a factor previously discussed as associated with heavy alcohol use.23,24

In conclusion, despite its limitations as a cross-sectional study, the present study found that heavy alcohol use among students in public middle and high schools in capital cities is associated with personal and family variables. While maintaining a good relationship with the parents and following a religion seem negatively associated with heavy alcohol use, working was shown as the most positively associated factor. The prevention of alcohol use does not depend on public and private programs only, but also on strengthening family and religious bonds.

REFERENCES

  • 1. Blum RW, Halcón L, Beuhring T, Pate E, Campell-Forrester S, Venema A. Adolescent health in the Caribbean: risk and protective factors. Am J Public Health. 2003;93(3):456-60. DOI:10.2105/AJPH.93.3.456
  • 2. Bobrowski K. Adolescents' free time activities and substance use. Med Wieku Rozwoj. 2003;7(1 Pt 2):91-104. Polish.
  • 3. Cavaiola AA, Cavaiola CK. Basics of adolescent development for the chemical dependency professional In: Henry PB. Adolescent chemical dependency. New York: The Haworth Press; 1989.
  • 4. Chambers RA, Taylor JR, Potenza MN. Developmental neurocircuitry of motivation in adolescence: a critical period of addiction vulnerability. Am J Psychiatry. 2003; 160(6):1041-52. DOI:10.1176/appi.ajp.160.6.1041
  • 5. De Michele D, Formigoni MLOS. Drug use Brazilian students: associations with family, psychosocial, health, demographic and behavioral characteristics. Addiction 2004;99(5):570-8. DOI:10.1111/j.1360-0443.2003.00671.x
  • 6. Delva J, Wallace JM, O'Malley PM, Bachman JG, Lloyd D, Johnston D, et al. The epidemiology of alcohol, marijuana, and cocaine use among Mexican American, Puerto Rican, Cuban American, and other Latin American eighth-grade students in the United States: 1991-2002. Am J Public Health. 2005;95(4):696-702. DOI:10.2105/AJPH.2003.037051
  • 7. Eitle D, Turner RJ, Eitle TM. The deterrence hypothesis reexamined: sports participation and substance use among young adults. J Drug Issues. 2003;33(1):193-221.
  • 8. Faden V. Epidemiology. In: Galanter M, editor. Recent developments in alcoholis. New York: Kluwer Academic/Plenum Publishers; 2005. v.17, p.1-4.
  • 9. Graunbaum JA, Tortolero S, Weller N, Gingiss P. Cultural, social, and intrapersonal factors associated with substance use among alternative high school students. Addict Behav. 2000;25(1):154-1.
  • 10. Hosmer DW and Lemeshow S. Applied Logistic Regression. 2.ed. New. York: John Wiley & Sons;
  • 11. Johnson MK. Further evidence on adolescent employment and substance under differences by race and ethnicity. J Health Soc Behav. 2004;45(2):187-97. DOI:10.1177/002214650404500205
  • 12. Kish L. Survey sampling. New York: John Wiley & Sons Inc; 1967.
  • 13. Romano M, Duailibi S, Pinsky I, Laranjeira R. Pesquisa de compra de bebidas alcoólicas por adolescentes em duas cidades do Estado de São Paulo. Rev Saude Publica. 2007;41(4):495-501. DOI:10.1590/S0034-89102007000400001.
  • 14. Lorente FO, Souville M, Griffet J, Grélot L. Participation in sports and alcohol consumption among French adolescents. Addict Behav. 2004;29(5):941-6. DOI:10.1016/j.addbeh.2004.02.039
  • 15. Nonnemaker JM, Neely CA, Blum RW. Public and private domains of religiosity and adolescent health risk behaviors: evidence from the national longitudinal study of adolescent health. Soc Sci Med. 2003;57(11):2049-54. DOI:10.1016/S0277-9536(03)00096-0
  • 16. Peck SC, Vida M, Eccles JS. Adolescent pathways to adulthood drinking: sport activity involvement is not necessarily risky or protective. Addiction 2008;103(Suppl 1):69-83. DOI:10.1111/j.1360-0443.2008.02177.x
  • 17. Pinsky I, Sanchez M, Zaleski M, Laranjeira R, Caetano R. Exposure to alcohol advertising among youngsters in Brazil: results from the 2006 Brazilian national survey. Alcohol Clin Exp Res. 2007;31(6):245A.
  • 18. Osório-Rebolledo EA, Ortega de Medina NM, Pillon SC. Risk factors associated with drug abuse among adolescent students. Rev Lat-Am Enfermagem. 2004;12(Spec):369-75. DOI:10.1590/S0104-11692004000700011.
  • 19. Romano M, Duailib S, Pinsky I, Laranjeira R. Alcohol purchase survey by adolescents in two cities of State of Sao Paulo, Southeastern Brazil. Rev Saude Publica. 2007;41(4):495-501. DOI:10.1590/S0034-89102007000400001
  • 20. Sanchez ZM, Oliveira LG, Nappo AS. Fatores protetores de adolescentes contra o uso de drogas com ênfase na religiosidade. Cienc Saude Coletiva. 2004;9(1):43-55. DOI:10.1590/S1413-81232004000100005
  • 21. Scivoletto S. Tratamento psiquiátrico de adolescentes usuários de drogas. In: Focchi GRA, Leite MC, Laranjeira R, Andrade AG. Dependência química: novos modelos de tratamento. São Paulo: Roca; 2001. p.65-85.
  • 22. Smart RG, Hughes PH, Jonhston LD, Anumonye A, Khant U, Medina-Mora ME, et al. A methodology for students drug use surveys. Geneva: World Health Organization; 1980. (WHO - Offset Publication, 50).
  • 23. Soldera M, Dalgalarrondo P, Filho HRC, Silva CAM. Uso de drogas psicotrópicas por estudantes: prevalência e fatores sociais associados. Rev Saude Publica. 2004;38(2):277-83. DOI:10.1590/S0034-89102004000200018
  • 24. Souza DPO, Silveira-Filho DX. Uso recente de álcool, tabaco e outras drogas entre estudantes adolescentes trabalhadores e não-trabalhadores. Rev Bras Epidemiol. 2007;10(2):276-87. DOI:10.1590/S1415-790X2007000200015
  • 25. Stylianou S. The role of religiosity in the opposition to drug use. Int J Offender Ther Comp Criminol. 2004;48(4):429-48. DOI:10.1177/0306624X03261253
  • 26. Tavares BF, Béria JU, Lima MS. Fatores associados ao uso de drogas entre adolescentes escolares. Rev Saude Publica. 2004;38(6):787-96. DOI:10.1590/S0034-89102004000600006
  • 27. Vieira DL, Ribeiro M, Laranjeira R. Evidence of association between early alcohol use and risk of later problems. Rev Bras Psiquiatr. 2007;29(3):222-7.
  • Factors associated with heavy alcohol use among students in Brazilian capitals

    Factores asociados al uso pesado de alcohol entre estudiantes de las capitales brasileras
  • Publication Dates

    • Publication in this collection
      22 Apr 2010
    • Date of issue
      Apr 2010

    History

    • Received
      09 Mar 2009
    • Accepted
      05 Aug 2009
    • Reviewed
      16 July 2009
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