Table 1

Infant mortality in relation to travel time to hospitals in Cumbria, 1950–93 by time period and adjusted for demographic risk factors (year of birth, social class, birth order, multiple births)

Accessibility function	1950–59			1960–69			1970–79			1980–93			1950–93
Accessibility function	Cases	OR (95% CI)	p	Cases	OR (95% CI)	p	Cases	OR (95% CI)	p	Cases	OR (95% CI)	p	OR (95% CI)	p
Early neonatal death	1048			904			560			323
Travel time (linear)		1.00 (0.99–1.00)	0.15		1.00 (1.00–1.01)	0.93		1.00 (0.99–1.00)	0.48		1.00 (0.99–1.01)	0.63	1.00 (0.99–1.00)	0.30
Travel time (categorical)
Category 1	665	1.00	0.50	604	1.00	0.98	383	1.00	0.51	198	1.00	0.42	1.00	0.67
Category 2	305	0.96 (0.84–1.10)		241	1.01 (0.87–1.18)		145	0.91 (0.75–1.10)		98	1.01 (0.79–1.29)		0.97 (0.89–1.06)
Category 3	78	0.87 (0.68–1.10)		59	0.99 (0.75–1.29)		32	0.87 (0.60–1.25)		27	1.32 (0.88–1.96)		0.95 (0.81–1.10)
Neonatal death	1267			1079			671			413
Travel time (linear)		1.00 (0.99–1.00)	0.04		1.00 (0.99–1.00)	0.78		1.00 (0.99–1.01)	0.77		1.00 (0.99–1.01)	0.81	1.00 (0.99–1.00)	0.14
Travel time (categorical)
Category 1	812	1.00	0.23	726	1.00	0.94	453	1.00	0.76	254	1.00	0.37	1.00	0.52
Category 2	364	0.94 (0.83–1.07)		280	0.98 (0.85–1.12)		177	0.94 (0.79–1.12)		125	1.01 (0.81–1.25)		0.96 (0.89–1.04)
Category 3	91	0.83 (0.67–1.04)		73	1.01 (0.79–1.29)		41	0.94 (0.68–1.30)		34	1.30 (0.91–1.87)		0.95 (0.83–1.09)
Postneonatal death	539			378			259			283
Travel time (linear)		0.99 (0.99–1.00)	0.09		1.00 (1.00–1.01)	0.33		1.00 (0.99–1.01)	0.50		1.00 (0.99–1.01)	0.39	1.00 (1.00–1.01)	0.99
Travel time (categorical)
Category 1	354	1.00	0.06	253	1.00	0.05	180	1.00	0.47	174	1.00	0.60	1.00	0.81
Category 2	153	0.90 (0.74–1.09)		88	0.89 (0.69–1.14)		67	0.92 (0.70–1.22)		92	1.14 (0.88–1.47)		0.97 (0.86–1.09)
Category 3	32	0.66 (0.46–0.96)		37	1.47 (1.04–2.09)		12	0.72 (0.40–1.29)		17	0.98 (0.59–1.62)		0.95 (0.77–1.17)