Tobacco and Public Health - TCSC Indonesia

JOHN P. PIERCE ET AL. 317
would be the impact of this on population prevalence? Obviously, smoking prevalence
cannot be maintained if there is no initiation to replace those who successfully quit or
who die. The rapidity of the effect on prevalence of smoking in the population can be
seen from the experience of United States physicians. At the time of the consensus that
smoking caused lung cancer, approximately half the physicians and medical students
smoked. However, the report appeared to have a huge effect on medical students; by the
early 1980s, only 2 per cent of students in US medical schools in the United States were
smoking (Pierce and Gilpin 1994). On the other hand, successful quitting among physicians
increased only slowly, in a pattern very similar to other highly educated people in
the society. However, within 20 years, the rapid and sustained decline in smoking initiation
led to a 6 per cent prevalence of smoking among US physicians (USDHHS 1989).
Studying trends in smoking uptake also provides valuable information on the likely
impact of different health promotion messages aimed at discouraging adolescents
from smoking. Between 1950 and 1964, there was a barrage of news media coverage on
the health consequences of smoking that was associated with many smokers quitting
(Pierce and Gilpin 2001). However, there was no discernable effect on initiation rates
of people aged 14–24 years. However, after the public health consensus that smoking
caused disease in 1964, there has been a continual decline in the proportion of neversmoking
adults (aged 18–24 years) who initiated smoking. This effect of the dissemination
of the health consequences of smoking in reducing the incidence of initiation in
young adults has been replicated in many countries. This declining pattern was not
observed among 14–17-year-old adolescents in the United States or anywhere else.
What is the process by which someone becomes a smoker?
Longitudinal studies of adolescents in the late 1980s and 1990s have shown that, at the
end of elementary school, children are generally committed never smokers, that is, they
do not envisage that there is any way that they will become a smoker. However, for
many this certainty does not last, and they eventually become unwilling to rule out
smoking in all situations, which we have defined as becoming susceptible to smoking.
Susceptible smokers indicate that their decision depends on the particular situation
they are in and many would describe themselves as curious about smoking. A series of
studies have demonstrated that susceptible never smokers are at twice the risk of smoking
of committed never smokers (Pierce et al. 1996; Unger et al. 1997; Jackson 1998).
Many studies have shown that the more experience a person has with smoking, the
greater the likelihood they will be a continuing smoker. Indeed, each increase in the
level of experience increases the probability of future smoking. However, this probability
decreases with time since the last smoking experience. What people expect they will
do in the future is also important. If an adolescent is certain that they will not try a cigarette
again, then their risk level is reduced (Choi et al. 2001). These variables can be put
together to create a continuum for assessing the probability of future smoking for any
individual at any point in time.