Table 4.

 Rate ratios (95% confidence interval) for mortality from ischaemic heart disease 1970-95 by birth weight adjusted for socioeconomic circumstances for all traced singleton live male births at Uppsala Academic Hospital, 1915-29

Adjustments*	Birth weight				P value for trend	Rate ratios per 1000 g increase in birth weight
	<3250 g (n=202†)	3250-3749 g (n=261†)	3750-4249 g (n=120†)	⩾4250 g (n=39†)
Crude	1.00	0.83 (0.69 to 1.00)	0.65 (0.52 to 0.81)	0.69 (0.49 to 0.97)	0.001	0.77 (0.66 to 0.90)
At birth‡	1.00	0.85 (0.71 to 1.02)	0.67 (0.53 to 0.84)	0.72 (0.51 to 1.02)	0.005	0.80 (0.68 to 0.93)
At 1960 and 1970 census§	1.00	0.86 (0.72 to 1.04)	0.67 (0.53 to 0.84)	0.72 (0.51 to 1.01)	0.006	0.80 (0.69 to 0.94)
At birth‡ and 1960 and 1970 census§	1.00	0.87 (0.72 to 1.04)	0.68 (0.54 to 0.86)	0.74 (0.53 to 1.05)	0.012	0.82 (0.70 to 0.96)

^*All rate ratios adjusted for period of birth as a three-level categorical variable (1915-9, 1920-4, 1925-9).  

^†Number of deaths from ischaemic heart disease.  

^‡Maternal marital status, parental social class.  

^§Occupational status at 1960 census; duration of education and earned income at 1970 census plus household car ownership at 1960 and 1970 censuses.