Increased Standardised Incidence Ratio of Malignant Pleural Mesothelioma in Taiwanese Asbestos Workers: A 29-Year Retrospective Cohort Study

Table 3

Observed and expected numbers and the SIR with the 95% CI for malignant pleural mesothelioma among the male workers employed in asbestos-related factories, by period of first employment in the factory and time since first employment: follow-up for 1980–2009.

Period of first employment	Time since first employment
	10–20 years			20–30 years			>30 years			Total
	Obs. ()	Exp. ()	SIR (95% CI)	Obs. ()	Exp.; ()	SIR (95% CI)	Obs. ()	Exp. ()	SIR (95% CI)	Obs. ()	Exp. ()	SIR (95% CI)
1950–1979	0	0.45	0.00 (0.00–8.12)	5	1.37	(1.19–8.52)	11	2.43	(2.25–8.09)	16	4.35	(2.10–5.98)
1980–1989	0	0.54	0.00 (0.00–6.79)	1	0.79	1.26 (0.03–7.03)	0	0.05	0.00 (0.00–70.78)	1	1.6	0.62 (0.00–3.48)
Total period	0	1	0.00 (0.00–3.70)	6	2.16	(1.02–6.04)	11	2.48	(2.21–7.92)	17	5.95	(1.66–4.57)

, . Obs. (): observed numbers. Exp. (): expected numbers; SIR: standardized incidence ratio; 95% CI: 95% confidence interval.