Table 3

Death rate ratio (95% confidence interval) according to smoking habits, body mass index, and social class for participants without pre-existing disease at the time of recruitment

		Ischaemic heart disease				All causes of death
		No of deaths (64)	Death rate ratio			No of deaths (392)	Death rate ratios
Smoking habits
Never smoked	22	100		173	100
Ex-smoker	25	131 (73–237)		131	112 (88–141)
Current smoker
< 10 cigarettes/day	5	128 (47–344)		34	125 (86–181)
⩾ 10 cigarettes/day	12	464 (224–959)^**		54	241 (176–329)^**
Body mass index (kg/m²)
< 20	8	158 (61–409)		81	141 (106–189)^*
20–	9	100		107	100
22.5–	23	269 (124–584)^*		117	135 (103–176)^*
⩾ 25	24	392 (180–851)^**		87	155 (116–207)^**
Social class
I–II	19	100		128	100
III–V	7	65 (27–155)		85	113 (86–149)
Others	38	118 (62–225)		179	115 (88–151)

Data adjusted for age, sex and for other variables listed.
Significance of difference from reference category: ^*2p < 0.05,^**2p < 0.01.