Table 3.

Standardised mortality ratios of smokers and never-smokers stratified by mode of identification.

	Smokers		Never-smokers
	O/E	SMR (95% CI)	O/E	SMR (95% CI)	RR (95% CI)
Respiratory cases	156/27.20	5.70 (4.90-6.70)	57/18.20	3.10 (2.37-4.06)	1.80(1.30-2.50)
Non-respiratory cases	35/11.20	3.10 (2.20-4.34)	44/15.40	2.85 (2.07-3.83)	1.10(0.70-1.70)
Screened cases	17/5	3.40 (1.98-5.43)	6/5	1.20 (0.44-2.63)	2.80(1.10-10.40)

O: Observed number of deaths.

E: Expected number of deaths from the general population.

CI: Confidence interval.

RR: Rate ratio.