[Factors affecting smoking of elementary and high school children from Chile].
BACKGROUND
Despite the harmful effects of tobacco millions of people continue to smoke. Many of these smokers, including most news smokers, are adolescents-both in Chile and in other countries. This study sought to determine the prevalence of smoking among Chilean elementary and high school children and to quantify the relative impact of socioeconomic, socio-cultural, familial, mass media exposure, demographic, educational and psychosocial factors on smoking.


METHODS
A representative sample of 2,967 elementary and high school children from Chile's Metropolitan Region were chosen at random, by grade (IV, VI, and VIII elementary school grades and I and IV high school grades), sex, type of school and geographical area. Prevalence of smoking was determined through an anonymous self-administered questionnaire. Socioeconomic status (SES) was measured by means of Graffar's modified method and family conditions, mass media exposure and psychosocial factors were registered. Scholastic achievement was measured by a language and mathematics test and other educational variables were considered. Statistical procedures included analysis of variance. Student's test and Scheffe's test for comparison of means, correlation, stepwise multiple regression, chisquared and PAHO/WHO risk approach methodology.


RESULTS
Prevalence of smoking (10.6%) increased significantly with age, from 1.3% in school children aged < 13 years to 15.4% and 36.9%, in adolescent students aged 13-15 years and > or = 16 years, respectively (p < 0.001) and was higher in females than in males. Pleasure level (r = 0.499 p < 0.001), level of rebelliousness (r = 0.124 p < 0.0001), family recreation level (r = -0.131 p < 0.0001) and the percentage of school attendance (r = -0.118 p < 0.0001) were the independent variables with the greatest explanatory power in smoking variance (r2 = 0.2860), but pleasure level was the variable with the greatest explanatory power in the explained variance (89.2%) and with the greatest RR (34.3). The relative impact of the independent variables on smoking varied according to age, sex and SES.


CONCLUSIONS
The result demonstrate that pleasure level, level of rebelliousness, family recreation level and the percentage of school attendance were the independent variables with the greatest explanatory power in smoking. These findings may be useful in the implementation of education and health policies with a view to the reduction of this serious public health risk factor.
Daniza Ivanovic
M
M
Instituto de Nutrición y Tecnología de los Alimentos da Universidad de Chile, Santiago, Chile.
Carmen Castro
G
G
Rodolfo Ivanovic
M
M
D000293:Adolescent; D000328:Adult; D002648:Child; D002677:Chile / Q000453:epidemiology; D003469:Culture; D004522:Educational Status; D005190:Family; D005260:Female; D006801:Humans; D008297:Male; D008402:Mass Media; D015995:Prevalence; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology*; D012959:Socioeconomic Factors