Prevalence of alcohol abuse and dependence in Rio Grande, state of Rio Grande do Sul: a cross-sectional, population-based survey

Abstracts

INTRODUÇÃO: O consumo de álcool é um problema de saúde pública muito relevante. O objetivo do presente estudo foi identificar a prevalência de alcoolismo e explorar possíveis fatores que contribuam para esse hábito. METODOLOGIA: Foi realizado um estudo transversal de base populacional no município de Rio Grande (RS), constando de uma amostra de 1.044 indivíduos, de ambos sexos, com idade entre 12 e 75 anos. Definiu-se dependência de álcool pelo questionário CAGE, e o abuso de álcool foi caracterizado pelo consumo de 30 ou mais gramas por dia para homens e 24 ou mais gramas por dia para mulheres. Para controlar o efeito de fatores de confusão, procedeu-se a uma análise multivariada por regressão logística. RESULTADOS: 5,5% dos indivíduos abusavam de álcool, dos quais 2,5% eram dependentes. Após controle por possíveis fatores de confusão, identificou-se uma associação significativa entre alcoolismo e as seguintes variáveis: sexo masculino (razão de chances - RC = 6,28), tabagismo (RC = 5,42) e classe social E (RC = 5,37). CONCLUSÃO: Os resultados identificaram as dificuldades de se realizar um estudo de base populacional sobre alcoolismo e revelaram que homens que fumam e são de classe social mais baixa têm uma chance maior de apresentar problemas vinculados ao álcool. A prevalência de abuso de álcool em Rio Grande foi de 5,5%, e de dependência, 2,5%.

Álcool; abuso; dependência; epidemiologia; estudo transversal; atenção primária

ORIGINAL ARTICLE

Prevalence of alcohol abuse and dependence in Rio Grande, state of Rio Grande do Sul: a cross-sectional, population-based survey

Prevalencia del abuso y de la dependencia de alcohol en Rio Grande (RS): un estudio transversal de base poblacional

Newton Luiz Numa Peixoto Primo^I; Airton Tetelbom Stein^II

^IProfessor of Medical Practice, Department of Internal Medicine, Fundação Universidade de Rio Grande, Brazil

^IIProfessor of Epidemiology, Fundação Faculdade Federal de Ciências Médicas de Porto Alegre; Graduate Program in Community Health, Universidade Luterana do Brasil, Brazil. Assistente de Coordenação de Ensino do Grupo Hospitalar Conceição

^{Correspondence}

ABSTRACT

INTRODUCTION: Alcohol consumption is serious public health issue. This study aimed at determining the prevalence of alcohol consumption in a southern Brazilian municipality and at investigating associated factors.

METHODS: A cross-sectional population-based survey was carried out in the municipality of Rio Grande, southern Brazil, with a sample of 1,044 people, both male and female, aged 12 to 75 years. Alcohol dependence was defined according to the CAGE questionnaire, and alcohol abuse was defined as the daily consumption of at least 30 grams of alcohol for men and 24 grams for women. Potential confounding factors were controlled in the multivariate analysis (logistic regression).

RESULTS: Alcohol abuse was found in 5.5% of the sample, and dependence in 2.5%. After adjusting for confounding factors, a significant association was observed between alcohol consumption and the following variables: male gender (odd ratio — OR = 6.28), smoking (OR = 5.42), and social class E (OR = 5.37).

CONCLUSION: Our results revealed the difficulties involved in the performance of a population-based study to assess alcohol consumption and showed that men who smoke and come from lower-income groups have greater chances of presenting alcohol-related problems. The prevalence of alcohol abuse in Rio Grande was of 5.5%, and of alcohol dependence, of 2.5%.

Keywords: Alcohol, abuse, dependence, epidemiology, cross-sectional study, primary care.

RESUMEN

INTRODUCCÍON:El consumo de alcohol es un problema de salud pública muy relevante. El objetivo de este estudio fue identificar la prevalencia de alcoholismo y explorar posibles factores de riesgo.

METODOLOGÍA: Se hizo un estudio transversal de base poblacional en Rio Grande (RS), con una muestra de 1.044 individuos de ambos sexos, con edades entre 12 y 75 años. La dependencia de alcohol fue definida por el cuestionario CAGE, y el abuso de alcohol fue caracterizado por el consumo de 30 o más gramos / día para hombres y 24 gramos / día para mujeres. Para controlar el efecto de factores de confusión, se hizo un análisis multivariado por regresión logística.

RESULTADOS: El 5,5% de los individuos abusaban del alcohol, siendo el 2,5% dependientes. Después del control por posibles factores de confusión, se identificó una asociación significativa entre el alcoholismo y las siguientes variables: sexo masculino (razón de chances — RC = 6,28), tabaquismo (RC = 5,42) y clase social E (RC = 5,37).

CONCLUSIÓN: Los resultados identificaron las dificultades de realizar un estudio de base poblacional sobre alcoholismo y revelaron que hombres que fuman y pertenecen a clases sociales más bajas tienen una mayor posibilidad de presentar problemas vinculados al alcohol.

Palabras clave: Alcohol, abuso, dependencia, epidemiología, estudio transversal, atención primaria.

INTRODUCTION

Alcohol consumption is recognized as a public health problem.^1,2

The proportion of people dependent on alcohol in relation to lifelong usage is, according to CEBRID,³ 20% for men and 10% for women. In the United States, costs from tobacco, alcohol and other drug usage reaches 238 billion dollars per year with 98.6 billion of this is spent as a result of alcohol use.⁴

The life expectancy of alcoholics in the United States is reduced by an average of 15 years, with causes of death, in descending order, being: cardiovascular disease, cancer, traffic accidents and suicide. The number of hospital admissions resulting from problems related to the use of alcohol reaches 32%.⁴ In the same country, the prevalence of alcoholism reaches 5 to 10%;⁴ in Latin America it is 3 to 23%;⁵ in Brazil 3.4 to 9%;^1,3,5 and in Pelotas (Rio Grande do Sul State), the prevalence is 9%.⁶

The objectives of the present study are: to identify the prevalence of alcohol abuse and dependency in the urban area of the town of Rio Grande (RS) among individuals from 12 to 75 years of age; to find evidence for any existing associations between biological, demographic, socioeconomic and behavioral factors and alcohol abuse and dependency.

MATERIAL AND METHODS

The study design employed was a cross-sectional populational study of individuals from 12 to 75 years resident in the town of Rio Grande.

The software program Epi-Info was used for sample size calculations, defining the basic parameters as statistical power of 80%, prevalence of disease of 9% (based on the study of Pelotas)⁶ and prevalence ratio (PR) of 1.5. Thus the estimated sample size was 1,156 individuals.

A standardized, pre-coded questionnaire was used with 86 questions covering the study variables, which were part of the SRQ-20 (Self-Report Questionnaire) and the CAGE.

The SRQ-20 is a questionnaire containing 20 questions with simple responses (yes/no), indicating probable cases of minor psychiatric disorders. The cut-off for positivity is five or more affirmative responses for men and seven or more for women.

The CAGE questionnaire is used to estimate the magnitude of alcoholism at companies or among populations, and includes four basic questions of alcohol intake: C (cut-down), A (annoyed), G (guilty), and (eye-opener). The cut-off for positivity of this test is two or more positive responses.

The independent variables studied were: sex, skin color, age, social class, education, income, smoking habit, alcohol consumption, coffee, chimarrão (Ilex Paraguariensis), obesity, physical activity, minor psychiatric disorders, family history of alcohol consumption, origin, employment status and occupation.

Dependent variables were alcohol abuse and alcohol dependence. Alcohol abuse was defined as daily intake of more then 30 grams for men and 24 grams or more by women.⁷ Alcohol dependence was defined as two or more positive responses to the CAGE questions.

Sociodemographic profiling was done using the Brazilian Economic Classification Questionnaire (Critério de Classificação Econômica Brasil — CCEB) from the Brazilian Association of Market Research Institutes (Associação Brasileira de Institutos de Pesquisa de Mercado — ABIPEME), which estimates the purchasing power of urban people and families, splitting them into economic classes.

Obesity was measured by means of a body mass index above 30 kg/m². Twenty-five census zones (conglomerations), with 1,044 people being interviewed. Homes at which there was refusal to participate or where no resident was found, and also those where individuals within the specified age group were absent at the first visit were visited a second time. Refusals and people difficulty to access were not substituted being considered as losses. Collective residences, such as, hotels, prisons and schools, were excluded from the study.

Double input was used and compared with Epi-Info, in an attempt to check for consistency. Errors that were detected were checked against the original questionnaire and the input set with the lowest density of failures was corrected.

The univariate analysis was descriptive, the bivariate analysis used the chi-square test; the effect measurement was PR. For multivariate analysis, logistic regression was used, employing odds ratios (OR) and confidence interval (CI) for the measure of effect. Statistical significance was set at p<0.05.

Data was considered confidential and all interviewees gave informed consent.

RESULTS

The sample under study was composed of 1,044 people, and losses were 9.7%. There was a predominance of white people, those who lived with a partner, females and individuals at social class C. With respect of education (in years of schooling), one third of the people in the sample had passed the first level of the current formal school structure. Fifty-six percent of the people studied said they had been born in Rio Grande. Unemployment was at 20.4% of the economically active population (EAP) (Table 1).

It was found that 26% were smokers and that, of these, 76% smoked more than 10 cigarettes/day. The rate of consumption of chimarrão was 59.2% of the sample; of these 60% exhibited the habit as a daily pattern. Coffee consumption was positive in 79.5%, and, of these, 83.7% consumed coffee daily. The study identified 88.2% as sedentary, 16.2% as obese and 22.5% as having minor psychiatric disorders.

Approximately one third of the sample revealed a family history of alcohol consumption and had ingested alcohol during the last month. Of these last 24% drank beer, 4.6% wine and 2.5% cachaça (sugar cane spirits); 5.5% were abusing alcohol, and 2.5% were dependent on alcohol (Table 2).

The bivariate analysis found evidence of a significant association between the dependent variables of alcohol abuse and dependence with male sex, age between 30 and 49 years, individuals belong to social class E, family history positive for alcohol consumption, chimarrão consumption and tobacco consumption.

In order to control confounding factors a multivariate analysis by logistic regression was employed, which sustained the association between alcohol abuse and dependence and the variables male sex (OR = 6.28), smoking (OR = 5.42) and social class E (OR = 5.37) (Table 3).

DISCUSSION

Cross-sectional studies are widely used to investigate the prevalence of conditions, allowing for better health planning and to generate hypotheses for new studies.^1,5,6,8,9

The distribution of this sample by skin color, sex, marital status and minor psychiatric disorders is comparable with the distributions found in other studies undertaken in Pelotas (RS),⁶ Porto Alegre (RS)⁷ and Rio de Janeiro (RJ).^10,11

Alcohol consumption found in populational samples in the United States (90%) and Australia (87%) found similar values. Consumption exhibited in Canada (75%), while below the figures cited above, is significantly above that of Colombia and Mexico (51%), which is comparable with Rio de Janeiro (52%).¹⁰ The consumption revealed by the present study indicates a surprisingly lower proportion (33%).

Abusive alcohol consumption observed in a study performed in Porto Alegre (15%)¹¹ was above that of Pelotas (9%)^6,11 and of Rio Grande (5.5%).

Alcohol dependence in Rio Grande, which was 2.5% (according to CAGE)^4,12,18, was significantly below that found at the United States (5% for women and 10% for men) and in Porto Alegre (9%)⁷, and is very similar to the values found in Pelotas (4%)^6,11 and Rio de Janeiro (3%)¹⁰.

The disparity towards lower alcohol consumption and abuse found in Rio Grande when compared with other studies may be the result of the losses that occurred during this study, in the hypothesis that non-respondents present higher proportions of alcohol consumption than those who did respond to the questionnaire. Nevertheless, the possibility remains that the findings do reflect reality.^19,20

The present study found evidence of prevalence rates for of alcohol abuse and dependence approximately two times lower in Rio Grande than in Pelotas. Taking the limitations into account, the results of this study found a lower proportion of positivity on CAGE than in studies in Pelotas, Porto Alegre, Rio de Janeiro and the United States. One possible interpretation for this variation might be the magnitude of the losses, at 9.7% (selection bias).

Six of the variables exercised an effect on alcohol abuse and dependence: one socioeconomic type (social class E), three biological types (age 30 to 49 years, male sex, family history of consumption) and two behavioral types (tobacco and chimarrão). The association between tobacco use and alcohol abuse and dependence is confirmed by the literature.^3,8,11,21-25 Nevertheless, because exposure and outcome were sampled at the same time it is necessary to call attention to possible reverse causality.

Under multivariate analysis, the variables family alcohol consumption, age and chimarrão consumption no longer exhibited significant associations while the variables sex, tobacco and social class E maintained their effects on alcohol abuse and dependence.

CONCLUSIONS

The performance of this research study has found evidence of the difficulties involved in conducting a populational study of alcoholism. It is estimated that in Rio Grande, 5.5% of the population abuse alcohol and 2.5% are dependent on it. The subset of male smokers of low socio-economic level is most vulnerable to alcohol abuse and dependence. The health services in Rio Grande should develop campaigns to reduce alcohol use, with special attention paid to this stratum of the population.

REFERENCES

Received on July 22, 2004.

Revised on July 27, 2004.

Approved on November 30, 2004.

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Publication Dates

• Publication in this collection
  14 Sept 2005
• Date of issue
  Dec 2004

History

• Accepted
  30 Nov 2004
• Reviewed
  27 July 2004
• Received
  22 July 2004