Tobacco and Public Health - TCSC Indonesia

the effects of smoking and smoking cessation on many health end points in women
(Kawachi et al. 1997; US Department of Health and Human Services 2001).
Kaiser Permanente Study
Between 1979 and 1986, the Kaiser Permanente Medical Care Program obtained baseline
information about tobacco smoking from 36 035 women and 24 803 men aged 35
years or older (Friedman et al. 1997). Participants in the program made up about 30
per cent of the population in the areas it served. Follow-up through 1987 identified
1098 deaths among all women. The study provides the only published data on premature
death associated with cigarette smoking among African-American women.
Cancer Prevention Study II (CPS-II)
The third large prospective study, begun by the American Cancer Society, was called
Cancer Prevention Study II (CPS-II). Started in 1982, it is a prospective mortality study
of nearly 1.2 million adults, 30 years of age and older, drawn from the entire population
of the USA. Like CPS-I, it included more than 50 per cent women. Enrollment
into the study was accomplished by completing a brief confidential mailed questionnaire
addressing alcohol and tobacco use, diet and other factors affecting mortality.
Deaths were ascertained from month of enrollment through 1988 by personal inquiries
by American Cancer Society volunteers at 2-year intervals. Follow-up after 1988 has
continued through linkage with the National Death Index. Analyses of smoking and
mortality have largely been restricted to the first 6 years of follow-up, since information
on tobacco use was not updated after enrollment. By 1988, 2 per cent of the cohort
were lost to follow-up and 0.2 per cent could not be followed because the personal
identifiers provided were insufficient for linkage to the National Death Index. By 1991,
12 per cent of the cohort had died and death certificates were obtained for 98 per cent
of the deceased. Participants in CPS-II were more likely to be white (93 per cent),
married (81 per cent), middle class, and educated (high school graduates or above,
85.6 per cent) than the general population of the United States of America.
Contributions of later cohort studies
MICHAEL J. THUN AND JANE HENLEY 27
Continuing follow-up of the original cohorts and the initiation of new large cohort
studies proved essential to the scientific consensus that smoking caused a multiplicity
of diseases besides lung cancer. One advantage of cohort studies was their ability to
examine many end points simultaneously. Initially this invoked criticism of the lung
cancer hypothesis—Berkson argued that smoking was associated with so many different
diseases that none of the associations were interpretable (Berkson 1955, 1958).
However, the relative risk for lung cancer was 10.8 among all cigarette smokers, compared
to non-smokers, in the seven cohort studies analyzed by the 1964 Advisory
Committee to the Surgeon General (US Public Health Service 1964) and was 24 among