Table 3.

Observed and expected deaths from coronary heart disease by age group and time period for patients with and without known coronary disease at registration

Attained age (years)	Person-years observation	1 January 1980 to 31 December 1991						Person-years observation	1 January 1992 to 31 December 2006
		Observed	Expected	SMR	95% CI	P-value	Rate/100 000		Observed	Expected	SMR	95% CI	P-value	Rate/100 000
Primary prevention
20–39	2031	3	0.08	3750	773–10 959	<0.001	148	8227	3	0.26	1153	238–3372	<0.01	37
40–59	2181	8	2.34	342	148–674	<0.01	367	13123	13	9.19	141	75–242	0.28	99
60–79	686	1	3.63	27	1–153	0.25	146	8219	29	34.33	84	57–121	0.41	353
20–79	4898	12	6.05	198	102–346	0.04	212	29 569	45	43.78	103	75–138	0.89	145
Secondary prevention
20–39	178	5	0.01	50000	16 235–116 683	<0.0001	2816	229	1	0			0	436
40–59	1016	9	1.58	570	260–1081	<0.0001	886	3419	34	3.83	888	615–1241	<0.0001	995
60–79	539	11	3.24	340	169–607	<0.001	2038	4509	73	24.01	304	238–382	<0.0001	1619
20–79	1733	25	4.83	515	335– 764	<0.0001	1442	8157	108	27.84	388	318–468	<0.0001	1324