Table 4.

Widths of 95% confidence interval of unconditional and conditional logistic regression models under the null hypothesis.

	Age distribution of unexposed and exposed subjects (in years)
	N(65, 102) vs. N(70, 102)		N(60, 102) vs. N(70, 102)		N(50, 102) vs. N(70, 102)
d	Unconditional	Conditional	Unconditional	Conditional	Unconditional	Conditional
Odds ratio associated with a 10-year increase in age = 1
0	0.60	0.61	0.57	0.58	0.52	0.60
1	0.58	0.59	0.60	0.61	0.51	0.59
2	0.62	0.63	0.58	0.60	0.50	0.58
3	0.61	0.62	0.59	0.60	0.50	0.58
Odds ratio associated with a 10-year increase in age = 1.5
0	0.61	0.62	0.57	0.58	0.49	0.56
1	0.56	0.57	0.56	0.57	0.48	0.54
2	0.58	0.58	0.56	0.57	0.48	0.54
3	0.60	0.62	0.55	0.56	0.50	0.56
Odds ratio associated with a 10-year increase in age = 2
0	0.57	0.58	0.56	0.57	0.50	0.56
1	0.59	0.61	0.53	0.54	0.50	0.57
2	0.57	0.59	0.56	0.57	0.51	0.58
3	0.60	0.61	0.56	0.58	0.52	0.59
Odds ratio associated with a 10-year increase in age = 3
0	0.58	0.59	0.56	0.57	0.53	0.59
1	0.57	0.58	0.53	0.54	0.50	0.57
2	0.57	0.58	0.55	0.57	0.52	0.60
3	0.61	0.63	0.54	0.56	0.53	0.61

Cases and controls were matched by age ± d. The odds ratio associated with the exposure was 1 under the null hypothesis, H₀: β_e = 0. Numbers of matching sets were 400, 500, and 900 in the three scenarios of age distributions.