Table 1.

Results from logistic regression analyses on grandpaternal ages and autism risk

	No of controls (%) Model 1-3	No of cases (%) Model 1-3	OR	CI	OR	CI	OR	CI	OR	CI
			Model 1		Model 2		Model 3		Model 4
Maternal grandfather age, years
<20	675 (2.18)	122 (2.06)	0.96	0.79-1.18	0.91	0.74-1.12	0.91	0.73-1.12	0.90	0.73-1.11
20-24	6721 (21.73)	1253 (21.11)	1.00		1.00		1.00
25-29	9801 (31.69)	1787 (30.10)	0.98	0.91-1.06	1.07	0.98-1.17	1.07	0.98-1.17	1.08	0.99-1.18
30-34	7082 (22.90)	1334 (22.47)	1.01	0.93-1.10	1.18	1.06-1.31	1.18	1.06-1.31	1.19	1.07-1.32
35-39	3868 (12.51)	808 (13.61)	1.10	1.00-1.22	1.33	1.17-1.50	1.32	1.16-1.50	1.31	1.15-1.49
40-44	1843 (5.96)	393 (6.62)	1.12	0.99-1.27	1.32	1.13-1.55	1.31	1.11-1.53	1.32	1.12-1.54
45-49	666 (2.15)	154 (2.59)	1.22	1.01-1.46	1.39	1.12-1.73	1.37	1.10-1.71	1.34	1.07-1.67
≥ 50	267 (0.86)	85 (1.43)	1.67	1.30-2.15	1.90	1.44-2.51	1.87	1.42-2.48	1.79	1.35-2.37
Paternal grandfather age, years
<20	702 (2.27)	123 (2.07)	0.96	0.79-1.18	0.88	0.72-1.09	0.88	0.72-1.09	0.91	0.73-1.12
20-24	6293 (20.35)	1139 (19.19)	1.00		1.00		1.00
25-29	9694 (31.35)	1793 (30.21)	1.02	0.94-1.11	1.09	1.00-1.19	1.09	0.99-1.19	1.10	1.00-1.20
30-34	7046 (22.79)	1387 (23.37)	1.08	0.99-1.17	1.18	1.06-1.31	1.17	1.05-1.30	1.17	1.05-1.30
35-39	4277 (13.83)	831 (14.00)	1.05	0.95- 1.16	1.17	1.04-1.33	1.17	1.03-1.32	1.15	1.02-1.31
40-44	1971 (6.37)	405 (6.82)	1.11	0.98-1.26	1.26	1.08-1.47	1.24	1.06-1.46	1.23	1.05-1.44
45-49	672 (2.17)	180 (3.03)	1.45	1.22-1.74	1.64	1.34 -2.02	1.62	1.32-1.99	1.60	1.30-1.97
≥ 50	268 (0.87)	78 (1.31)	1.56	1.20-2.02	1.76	1.32-2.35	1.72	1.29-2.30	1.67	1.25-2.24

OR:Odds ratios

CI: 95% Confidence Intervals

Model 1: Adj for birth year, sex

Model 2: Adj for birth year, sex, age of spouse

Model 3: Adj for birth year, sex, age of spouse, family history

Model 4: Adj for birth year, sex, family history, highest education, county

Model 1-3: controls=30923 cases=5936

Model 4: controls=30904 cases=5933