Table 2.

Odds ratio of having experienced adolescent induced abortions among women in different birth cohorts

Birth cohorts	Total	By residence		By education level			By ethnic groups
		Urban	Rural	Junior middle school or below	High school	College or above	Han	Minorities
	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)
15-19	0.21 (0.15, 0.29)	0.12 (0.06, 0.24)	0.27 (0.19, 0.38)	0.29 (0.20, 0.41)	0.05 (0.02, 0.12)	0.75 (0.17, 3.29)	0.17 (0.12, 0.25)	0.34 (0.19, 0.60)
20-24	1.25 (1.07, 1.46)	1.06 (0.80, 1.41)	1.36 (1.13, 1.63)	1.62 (1.35, 1.95)	1.14 (0.83, 1.55)	1.21 (0.56, 2.61)	1.18 (1.00, 1.41)	1.43 (1.00, 2.03)
25-29	Reference	Reference	Reference	Reference	Reference	Reference	Reference	Reference
30-34	0.79 (0.68, 0.91)	0.79 (0.61, 1.02)	0.81 (0.68, 0.97)	0.72 (0.61, 0.85)	0.59 (0.41, 0.85)	1.73 (0.89, 337)	0.80 (0.68, 0.94)	0.70 (0.48, 1.01)
35-39	0.56 (0.48, 0.66)	0.53 (0.40, 0.71)	0.59 (0.49, 0.72)	0.48 (0.40, 0.57)	0.31 (0.20, 0.49)	1.33 (0.62, 2.82)	0.58 (0.49, 0.69)	0.47 (0.31, 0.71)
40-44	0.51 (0.43, 0.59)	0.53 (0.40, 0.70)	0.49 (0.41, 0.59)	0.37 (0.32, 0.44)	0.35 (0.23, 0.54)	0.72 (0.26, 2.01)	0.53 (0.45, 0.63)	0.37 (0.24, 0.56)
45-49	0.40 (0.34, 0.47)	0.49 (0.37, 0.65)	0.35 (0.29, 0.42)	0.28 (0.24, 0.34)	0.18 (0.11, 0.32)	0.78 (0.26, 2.38)	0.45 (0.38, 0.52)	0.13 (0.07, 0.24)
50-54	0.31 (0.27, 0.37)	0.44 (0.33, 0.59)	0.26 (0.21, 0.32)	0.22 (0.18, 0.26)	0.15 (0.09, 0.26)	0.30 (0.04, 2.29)	0.35 (0.29, 0.41)	0.12 (0.06, 0.23)
55-60	0.14 (0.11, 0.19)	0.19 (0.11, 0.31)	0.12 (0.09, 0.17)	0.11 (0.08, 0.15)	0.05 (0.02, 0.13)	0	0.14 (0.10, 0.19)	0.19 (0.09, 0.39)
p for trend	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001	0.15	< 0.001	< 0.001

The birth cohorts were grouped by the age (numerical variable) of women on the survey date. P values for trend were computed separately by each characteristic and indicate there are statistically significant trend in birth cohorts if P < 0.05