Prevalence of alcohol and drug consumption among adolescents: data analysis of the National Survey of School Health
Deborah Carvalho MaltaI; Márcio Dênis Medeiros MascarenhasII; Denise Lopes PortoIII; Eliane Aparecida DuarteIV; Luciana Monteiro SardinhaV; Sandhi Maria BarretoVI; Otaliba Libânio de Morais NetoVII
IGeneral Coordination of Non-Communicable Diseases (CGDANT) of the Health Surveillance Secretariat (SVS) at the Ministry of Health, Brasília (DF); Nursing School at Universidade Federal de Minas Gerais (UFMG) - Belo Horizonte (MG), Brazil
IICGDANT of the SVS at the Ministry of Health, Brasília (DF); Universidade Federal do Piauí (UFPI) - Teresina (PI), Brazil
IIIDepartment of Health Situation Analysis (DASIS) of the SVS at the Ministry of Health - Brasília (DF), Brazil
IVCGDANT of the SVS at the Ministry of Health, Brasília (DF), Brazil
VCGDANT of the SVS at the Ministry of Health, Brasília (DF), Brazil
VIMedical School at UFMG - Belo Horizonte (MG), Brazil
VIIDASIS of the SVS at the Ministry of Health - Brasília (DF), Brazil
OBJECTIVE: To describe the prevalence of alcohol and other drugs consumption, among adolescent students.
METHODS: A cross-sectional study with conglomerate samples of 60,973 students at freshman year high school in public and private schools in capitals and the Federal District in Brazil, in 2009. The 95% confidence interval and prevalence of alcohol and drug consumption were analyzed.
RESULTS: For the set of surveyed students, the following were identified: experimenting alcoholic beverages (71.4%; 95%CI 70.8-72.0); regular alcoholic beverage consumption (27.3%; 95%CI 26.7-28.0); drunkenness in lifetime (22.1%; 95%CI 21.6-22.7); family is worried when the student gets home drunk (93.8%; 95%CI 93.3-94.2); problems with alcohol use (9.0%; 95%CI 8.6-9.4); consumption of other drugs (8.7%; 95%CI 8.3-9.1).
CONCLUSION: The study shows the extension of the alcohol and drugs problem among Brazilian adolescents, with special emphasis on the easy access of students to alcoholic beverages at parties, bars, stores, and at homes.
Keywords: adolescence; school health; alcohol; drugs, risk behavior; risk factor; surveillance; chronic disease.
Adolescence is a stage of human development which is characterized by biological, cognitive, emotional and social changes that are important for reassuring and consolidating the habits of adult life. In this phase, it is common to experiment psychoactive substances, such as alcohol and illicit drugs. Alcohol use in adolescence is an exposure factor for health problems in the adult age, and it significantly increases the risk of the individual becoming an excessive consumer throughout life1.
Alcohol abuse is associated with negative consequences for the health of the population, since it is one of the main risk factors for vascular diseases, car accidents and homicides, which are the leading causes of death among youngsters2,3. Each year, approximately 5.2 million deaths are caused by accidents and violence all over the world, out of which around 1.8 million are associated with alcohol consumption4.
Alcohol use has proved to be a risk factor for the use of other substances, such as tobacco, illegal drugs, and for the manifestation of conditions like depressive disorders, anxiety, school fights, property damage and police-related problems4. Other studies reported that alcohol in adolescence is associated with the absence of parental relationship, the fact of studying in public schools, and school failure1,5.
The constant exposure of adolescents to alcohol advertisement was also related to alcohol consumption in this age group6,7. Some studies demonstrate that the lower the socioeconomic status, the higher the risk to consume alcohol in adolescence1. Besides alcohol, other drugs are important risk factors in this stage of life, since it is a vulnerable period to acquire the habit to consume psychoactive substances4.
Considering the importance of adolescence as a vulnerable stage of life to acquire habits that may last for life, the present study has the objective to describe the prevalence of alcohol use, as well as other drugs among adolescent students enrolled in private and public schools in Brazilian state capitals and the Federal District in 2009.
The results of the National Survey of School Health (Pesquisa Nacional de Saúde do Escolar - PeNSE) were analyzed, which was conducted by the Brazilian Institute of Geography and Statistics (IBGE) and the Ministry of Health, regarding students of the ninth grade enrolled in public and private schools of state capitals and the Federal District of Brazil in the first semester of 2009.
The conglomerate sample with two stages used data from the School Census 2007. Schools were selected in the first stage, and groups were divided in the second stage by interviews with students8. The sample size was calculated to estimate proportion (or prevalence) of some characteristics of interest in each geographic stratum (the 27 state capitals and the Federal District), with maximum error of 0.03 (3%) and 95% confidence interval (95%CI). Details on the survey may be obtained from specific publications8,9. The data collection instrument was elaborated in accordance with models used in previous national and international studies about adolescent behavior after adaptation to the Brazilian reality based on tests performed in schools of Rio de Janeiro, Belém and Recife9.
For PeNSE, the questionnaire was given to students of the selected groups by means of a portable computer operated by the student in the Personal Digital Assistante (PDA), which automatically registered the information. Data were stored throughout the day, being further transferred to one spreadsheet. The students who did not feel encouraged to participate in the study were considered as losses.
In total, 1,453 schools were selected, with 2,175 groups and 68,735 regular students. On the data collection day, 63,411 students were present; loss rate was 7.7% at this phase. Also, 501 students who refused to participate or did not fill in the variable "sex" were excluded from the sample. Thus, data from 60,973 students were analyzed with a non-response rate of 11.3%.
The statistical package SPSS10 was used to calculate the prevalence and the 95%CI regarding variables, which were analyzed according to sex and administrative management of the school (public or private) for the total of 26 state capitals and the Federal District, also enabling the identification of statistically significant differences.
The following aspects were analyzed: experimenting alcohol in life; drunkenness episodes in life; regular alcohol consumption or just in the previous 30 days; problems with family or friends due to alcohol use such as missing classes, getting hurt or fighting; family perception regarding drunkenness; and experimenting some other type of drug (marijuana, cocaine, crack, shoe glue, inhalants, ecstasy etc.).
The variables: experimenting alcohol and some other type of drug at least once were described for each capital according to sex and age and 95%CI. The number of alcohol glasses consumed per day in the past 30 days and how to get the alcohol were described, with respective 95%CI.
The study was approved by the National Commission on Ethics in Research (CONEP) of the Ministry of Health, amendment nº 005/2009, related to Register 11,537. The research was preceded by a contact with the State and County Secretaries of Education and the administration of the selected schools.
PeNSE revealed that 71.4% (95%CI=70.8-72.0) of students in the ninth year of elementary school have tried alcohol at least once. This situation was significantly higher among females (73.1%; 95%CI 72.3-73.9) from private schools (75.7%; 95%CI 74.6-76.8) when compared to males (69.5%; 95%CI 68.5-70.5) and students from public schools (70.3%; 95%CI 69.5-71.0), respectively (Table 1).
The prevalence of alcohol consumption also varied according to the city, ranging from 55.1% in Macapá to 80.7% in Curitiba. Among females, the capitals with higher prevalence levels were: Curitiba (82.3%; 95%CI 80.1-84.5), Porto Alegre (81.9%; 95%CI 79.2-84.6), Rio de Janeiro (79.4%; 95%CI 77.1-81.7), Campo Grande (79.3%; 95%CI 76.7-81.8), Florianópolis (78.4%; 95%CI 75.9-80.9), Belo Horizonte (77.6%; 95%CI 75.4-79.9), and São Paulo (77.1%; 95%CI 74.6-79.5). As to males, the highest prevalence was found in the following capitals: Curitiba (78.9%; 95%CI 76.4-81.3), Campo Grande (78.7%; 95%CI 75.9-81.4), Florianópolis (76.5%; 95%CI 73.8-79.1), Salvador (75.6%; 95%CI 72.6-78.5), Porto Alegre (74.7%; 95%CI 71.5-77.9), Rio de Janeiro (73.9%; 95%CI 71.4-76.4), Aracaju (73.6%; 95%CI 70.6-76.5) and Belo Horizonte (72.9%; 95%CI 70.2-75.6), as demonstrated in Figure 1.
Regular consumption of alcohol among students, based on the past 30 days, was of 27.3% (95%CI 26.7-28.0) for the state capitals and the Federal District. Females consumed more in the past 30 days (28.1%; 95%CI 27.2-29.0) than males (26.5%; 95%CI 25.5-27.5); however, the difference is not statistically significant. Regular consumption of alcohol was significantly higher among students from private schools (29.5%; 95%CI 28.2-30.8) in relation to those enrolled in public schools (26.8%; 95%CI 26.1-27.5), as demonstrated in Table 1.
The research showed that approximately one out of five students has already gotten drunk (22.1%; 95%CI 21.6-22.7), and such episodes were significantly more frequent among male (23.3%; 95%CI 22.4-24.2) than female adolescents (21.1%; 95%CI 20.3-21.9). The proportion of adolescents who have already gotten drunk was higher in public schools (22.8%; 95%CI 22.2-23.5) than in private institutions (19.4%; 95%CI 18.4-20.5), as demonstrated in Table 1.
When the adolescents were asked about their parents perception of them getting home drunk, most confirmed that the parents would be worried about the situation (93.8%; 95%CI 93.3-94.2). This perception was similar among females (93.2%; 95%CI 92.4-94.0) and males (92.5%; 95%CI 91.8-93.2), as well as among students from private (93.2%; 95%CI 93.4-94.4) and public schools (93.9%; 95%CI 92.4-94.0). Alcohol consumption was the cause of problems such as missing classes, injuries or fights for 9.0% (95%CI 8.6-9.4) of the students, with no differences between females and males, although such problems were more frequent among students from public schools (9.3%; 95%CI 8.5-9.5) in relation to those of private schools (7.6%; 95%CI 6.9-8.3) (Table 1).
Data from PeNSE showed that 8.7% (95%CI 8.3-9.1) of the students had already tried an illicit substance (marijuana, cocaine, crack, shoe glue, inhalants, ecstasy). The use of illicit drugs was significantly higher among male students (10.6%; 95%CI 10.0-11.3) and students from public schools (9.0%; 95%CI 8.5-9.5) (Table 1). In the capitals, the prevalence of illicit drug use ranged from 5.3% in Macapá to 13.2% in Curitiba. Among females, the capitals with the highest prevalence levels were: Curitiba (12.1%; 95%CI 10.2-14.0), Belo Horizonte (9.0%; 95%CI 7.5-10.6) and Natal (8.4%; 95%CI 6.8-10.0). As to males, the highest prevalence levels were observed in Curitiba (14.3%; 95%CI 12.2-16.5), Recife (14.3%; 95%CI 12.1-16.5) and João Pessoa (14.1%; 95%CI 11.7-16.5) (Figure 2).
Figure 3 shows the prevalence of the use of alcohol and other drugs according to age and sex. Alcohol consumption is more prevalent among individuals at the age of 12 and 13 years, and for females (20.6 versus 19.4 and 24.8 versus 23.0%, respectively). Males presented higher prevalence of alcohol use starting from the age of 14 (15.1 versus 13.0%). As to other illicit drugs, the age of first use varied, being more prevalent from 13 to 14 years old, especially among girls (30.4 versus 24.2% and 32.9 versus 27.6%, respectively), while for boys the age was 15 or older (15.6 versus 13.0%) (Figure 3). The number of alcohol doses had different distributions according to sex in two situations: consumption of less than one dose was higher among girls (29.9 versus 25.2%), while the consumption of more than five doses was significantly higher among boys (20.1 versus 15.2%) (Figure 4).
Among the adolescents who had drunk alcohol in the past 30 days, the simplest way to acquire alcohol was at parties (39.8%), followed by the purchase in markets, stores, supermarkets or bars (18.4%). Females could obtain alcohol more easily at parties (43.7 versus 35.1%) or at home (14.5 versus 11.5%). Males could get alcohol more frequently outside the household, by purchasing it in markets, stores, bars and supermarkets (23.0 versus 14.6%), or the street (5.0 versus 2.1%) (non-presented data).
PeNSE showed the prevalence of alcohol consumption and other drugs among students in state capitals and the Federal District. About three quarters of 13 to 15-year-old adolescents have already tried alcohol, around one quarter had regularly drunk in the past 30 days with drunkenness episodes, and 9% reported having had problems with alcohol. As to drugs, 8.7% reported having tried these substances at least once, and alcohol and drug use had happened too early. These data show the extension of the problem, which is so delicate, with Brazilian adolescents. There are different ways for adolescents to get alcohol, especially at parties, bars, stores and even at home.
Many studies show that alcohol use among adolescents has been very common in Brazil and throughout the world. In the United States, a national study11 revealed that the consumption of alcohol at least once was cited by 81.6% of the adolescents in 1997, and the frequency was reduced to 75% in 2007. A survey was conducted in Spain12 and showed that alcohol use among 13 to 14-year-old students was of 35.5% among boys and 27.3% among girls; this frequency increased in the group aged 15 to 16 years to 67.6% among boys and 71.9% among girls.
A study conducted by the Brazilian Center for Drug and Alcohol13 with 14 to 17-year-old adolescents living in 143 Brazilian cities showed that 75% of them had already consumed alcohol at least once. However, data from PeNSE presented similar prevalence levels to the ones observed in other countries, which demonstrates the extension of the problem in Brazil and throughout the world.
About 50% of the adolescents interviewed for PeNSE reported having consumed alcohol before the age of 12, information that is similar to the results observed in a study14 with students from the public elementary and high schools of the 27 state capitals in Brazil in 2004, which showed that the average age for initiating alcohol consumption was 12.5 years.
As to current consumption, or regular consumption in the past 30 days, the proportions were also elevated in other studies. In the United States11, 44.7% of the 14 to 17-year-old adolescents reported having drunk alcohol in the past month. In Pelotas, Rio Grande do Sul1, a cross-sectional study showed that, in 2005 and 2006, 23% of the adolescents aged 11 to 15 years consumed alcohol in the month prior to the research, 21.7% of men and 24.2% of women. The adolescents interviewed for PeNSE also reported consuming high levels of alcohol in the previous 30 days. Generally, the studies demonstrated that alcohol consumption has been elevated among youngsters.
A study carried out in 41 countries by the World Health Organization (WHO)4 showed that 11% of the students (9% of girls and 13% of boys) had drunk excessively or gotten drunk at least twice. About 22% of the adolescents interviewed for PeNSE reported having been drunk at least once. This situation may be considered serious, once it increases the chances that youngsters get involved in risky episodes, such as issues with the family and friends, and also at school; these situations were reported by 9% of the students analyzed by PeNSE.
Since alcohol use is socially acceptable, and even stimulated in most countries3, the exposure of adolescents to it has been increasing, thus, there are bigger chances of involvement in risky situations. The family is essential for the development of adolescents, thus, parental support in the activities performed by children is very important. Studies15,16 show that when parents are worried about the activities performed by their children, they show less involvement with alcohol, drugs and tobacco. The fact that adolescents considered that 93% of the parents would be upset in case they got home drunk shows the family as a space of protection, since parents are concerned about their children and discourage risk attitudes.
The increase in drug use among youngster is a serious issue in many countries. The most consumed illicit drug in Europe and the United States is marijuana, and its use among youngsters may be a sign of psychosocial disturbances, which elevates the chances of dependence in adult life. A survey conducted by WHO4 among adolescents in over 40 countries showed that 18% of 15-year-old adolescents had already tried marijuana during some period of life.
Usually, reports on drug use among students show that drugs such as alcohol, marijuana and tobacco are mostly used by males, while females use amphetamines and anxiolytics more frequently. Besides, licit drugs such as alcohol are used earlier when compared to psychotropic drugs13,14. A study conducted in 2004 with students from public elementary and high schools in the 27 state capitals showed that mean age to experiment drugs for the first time ranged from 12.5 to 14.4 years; cocaine had the highest mean (14.4 years old)14.
Data from PeNSE demonstrate the severity of the problem regarding alcohol and drug use among students, showing the early exposure, the dimension of the problem (more than 70% have been exposed to alcohol, and around 8% to drugs), leading to an increasing exposure to risks. It was also observed that adolescents have easy access to alcohol at parties, bars, stores and even at home.
Alcohol and drug advertising, among other problems, causes children and adolescents to develop consumption habits6. In order to reduce the prevalence of experimenting and regular use of alcohol in young and vulnerable populations, society must change its passive and stimulating behavior towards the issue, recognizing the risks of early exposure and proposing control measures, such as the prohibition of alcohol advertisement, especially beer. This has been the main tool to reduce tobacco use9.
Since the use of alcohol and drugs is associated with many other risk factors, leading to problems related to health and life of adolescents, families, schools and the society should take action to propose measures that promote health and prevent the use of such substances.
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Deborah Carvalho Malta
General Coordination of Non-Communicable Diseases
Department of Health Situation Analysis - Health Surveillance Secretariat, Ministry of HealthMinistry of Health
SAF Sul, Trecho 2, Lote 5/6, Torre I - Edifício Premium - Room 14 - Ground floor
CEP: 70070-600 - Brasília (DF), Brazil
Conflict of interest: nothing to declare.
Submitted on: 05/01/2011
Final version presented on: 03/02/2011
Accepted on: 04/02/2011
Financial Support: Ministry of Health