Table 5.

Age- and duration-standardized proportions of miners with silicosis, by population group and time interval (nonexternal causes of death), with time interval-specific SPRs (blacks to whites).

	Black			White
Year of autopsy	n	Proportion with silicosis		n	Proportion with silicosis		SPRa (95% CI)
		Crude	Standardized (95% CI)		Crude	Standardized (95% CI)
1975–1979	2,054	0.07	0.06 (0.05–0.07)	3,629	0.31	0.06 (0.05–0.07)	0.95 (0.72–1.27)
1980–1984	1,884	0.13	0.11 (0.09–0.12)	3,890	0.32	0.07 (0.04–0.09)	1.66 (1.18–2.34)
1985–1989	2,010	0.16	0.12 (0.10–0.13)	3,512	0.26	0.05 (0.03–0.07)	2.44 (1.55–3.82)
1990–1994	2,670	0.18	0.12 (0.10–0.13)	3,118	0.24	0.05 (0.03–0.06)	2.57 (1.70–3.89)
1995–1999	3,192	0.23	0.14 (0.12–0.15)	2,284	0.22	0.05 (0.04–0.06)	2.71 (2.01–3.67)
2000–2007	6,466	0.29	0.16 (0.15–0.17)	3,409	0.24	0.06 (0.04–0.09)	2.56 (1.66–3.95)
All years	18,276	0.21	0.13 (0.12–0.13)	19,842	0.27	0.06 (0.05–0.06)	2.27 (2.12–2.43)

^aSPRs indicate ratios of the standardized proportion of black miners with silicosis to the standardized proportion of white miners with silicosis.