Table 1

Rate of increase in mortality from sporadic Creutzfeldt-Jakob disease (definite and probable cases) by age group and genotype (1992–7)

		Number of deaths		Average yearly (%) increase in mortality (95% CI)	p Value
		1992–4	1995–7	Average yearly (%) increase in mortality (95% CI)	p Value
By age group:
30–59	27	40	8.4 (−6.1 to 25.2)	0.27
60–69	48	88	17.8 (6.5 to 30.3)	0.001
70–79	37	58	21.4 (7.4 to 37.1)	0.002
⩾80	6	20	42.5 (10.9 to 83.2)	0.005
By genotype:
Met-Met	59	110	20.4 (9.9 to 31.8)	0.001
Val-Val	8	33	50.5 (22.4 to 85.1)	0.001
Met-Val	13	17	14.7 (−9.2 to 38.7)	0.28