The National Health and Medical Research Council (NH & MRC) conducted surveys of Australian schoolchildren's smoking habits in 1967 and 1973. More recently, national surveys of schoolchildren's smoking habits have been coordinated by the Centre for Behavioural Research in Cancer (CBRC) within the Anti-Cancer Council of Victoria.(9,10,11,12) Because the two data series are not directly comparable, the NH & MRC reports will not be discussed further here. Hill et al (1984) provide analysis and, where possible, comparisons between the NH & MRC reports and the CBRC's 1984 survey.
The national surveys published to date by the CBRC have been undertaken every three years since 1984. Table 1.3 shows the percentage of students by sex and age group who were current smokers (classified on the basis as having smoked in the week prior to the survey) in the four survey years. Between 1984 and 1990, the prevalence of smoking among 12 to 15 year olds decreased. Among students aged 16 and 17 years old, the prevalence of smoking decreased between 1984 and 1987, but no change was found between 1987 and 1990.12
A different trend appears to have emerged between 1990 and 1993. The proportion of male current smokers in 1993 is higher than that found in 1990 in all age groups. Among girls, the proportion of female current smokers in 1993 is greater than or equal to that found in 1990 among all age groups.(12) Among 12 to 15 year-olds, the proportion of secondary school students who are current smokers has increased, the increase among boys being more pronounced than that among girls. The proportion of 16 to 17 year olds who are current smokers may also have increased, but these data do not reach statistical significance.(12) Hill et al observe that the trend towards reduced student smoking seen throughout the 1980s appears to have ended, although the increase noted appears to be among 'experimental' rather than 'committed' smokers (the proportion smoking on three or more days per week).(12)
In all survey years, smoking prevalence was higher among girls than boys in all but the youngest age sample; however in the 1993 survey this difference only reached statistical significance among 15 year olds(12) In general, boys who smoke, smoke more heavily than girls who smoke (although neither group smokes as heavily as the average adult smoker -- see Chapter 2, Section 3 for further discussion).
In 1993, the prevalence of smoking among students aged 15-16 was close to the adult smoking prevalence, if one considers the proportion who smoke at least once a week. The main developmental period of uptake of current smoking among schoolchildren therefore appears to be between the ages of 12 and 16 years.(11)
It is important to note that because these surveys are confined to schoolchildren, rates measured for the 16-17 year old age groups may not be representative for all teenagers of these ages as they do not account for those who have left school. However in response to Australia's economic downturn in the late 1980s and early 1990s, school retention rates have increased dramatically (from 45% in 1984, to 64% in 1990 and 77% in 1993). Hill et al note that because of this factor, the population in the older age groups is likely to have changed over the study years.(12) It therefore follows that the 1993 data are more likely to be representative of the smoking behaviour of the overall teenage population than in previous years. However, teenagers outside the school system may have a higher prevalence of smoking. Higher achieving students are more likely to remain at school for longer than lower achievers, and academic standard is related to school age smoking.(13) Teenagers who have left school may also receive a greater degree of exposure to tobacco use, whether in the workplace (see also Chapter 10), or in a peer group where unemployment is common (the unemployed in general exhibiting higher smoking rates -- see Table 1.5 below).