Cigarette smoking and mortality in Japan: the Miyagi Cohort Study.
BACKGROUND
We examined the association between smoking and all-cause mortality among Japanese men and women.


METHODS
In 1990, 18,945 men and 17,107 women in Miyagi Prefecture in rural northern Japan (40-64 year of age) completed a self-administered questionnaire including items on smoking. Cox regression was used to estimate relative risk (RR) of mortality according to smoking categories, with adjustment for age, education, marital status, past history of diseases, drinking, body mass index, walking, and dietary variables. During 11 years of follow-up, 1,209 men and 499 women had died.


RESULTS
Multivariate RRs of all-cause mortality for current smokers as compared with never smokers were 1.71 (95% confidence interval, 1.44-2.03) for men and 1.44 (95% confidence interval, 1.06-1.94) for women. Among men, risk in past smokers who had quit smoking for 15 years or longer was not different from the risk in never smokers (RR, 0.97; 95% confidence interval, 0.68-1.39). Of all deaths, 34% in men and 4% in women were attributable to current or past smoking.


CONCLUSIONS
This study indicates that smoking increases the risk of premature death among middle-aged Japanese men and women and that substantial proportion of death, especially for men, is attributable to smoking.
Hozawa
Atsushi
A
Division of Epidemiology, Department of Public Health and Forensic Medicine, Tohoku University Graduate School of Medicine, Sendai, Miyagi 980-8575, Japan.
Ohkubo
Takayoshi
T
Yamaguchi
Junko
J
Ugajin
Takashi
T
Koizumi
Yayoi
Y
Nishino
Yoshikazu
Y
Tsubono
Yoshitaka
Y
Shibuya
Daisuke
D
Tsuji
Ichiro
I
Fukao
Akira
A
Hisamichi
Shigeru
S
D000328:Adult; D015331:Cohort Studies; D005260:Female; D006306:Health Surveys; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008019:Life Style; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012907:Smoking / Q000401:mortality*