Table 2. Reproductive and lifestyle factors and the risks of endometriosis and adenomyosis.

		Imaging-diagnosed endometriosis				Imaging-diagnosed adenomyosis				Wald test between endometriosis and adenomyosis
		n	Cochran- Armitage trend test	Odds ratio	95% CI	n	Cochran- Armitage trend test	Odds ratio	95% CI
Age (years)				0.991	0.977–1.01			1.04	1.02–1.05	χ2 = 20.4 P < 0.001
Age at menarche (years)	≤11	77	0.001	0.905	0.670–1.22	57	0.863	1.17	0.816–1.67	χ2 = 10.8 P = 0.095
	12	107		ref.		70		ref.
	13	71		0.843	0.621–1.14	61		1.01	0.715–1.43
	≥14	54		0.609	0.436–0.851	60		0.870	0.611–1.24
Length of menstrual cycle at 18–22 years of age (days)	≤25	37	<0.001	1.19	0.837–1.70	25	0.579	1.07	0.698–1.64	χ2 = 20.0 P = 0.003
	26–31	211		ref.		153		ref.
	32–49	43		0.557	0.400–0.776	46		0.856	0.613–1.20
	≥50	18		0.569	0.349–0.928	24		1.16	0.748–1.80
Smoking at 30 years of age	Never	207	0.046	ref.		169	0.155	ref.		χ2 = 8.2 P = 0.017
	Ever	102		1.31	1.03–1.67	79		1.30	0.990–1.71
BMI at 18 years of age	<18.5	30	0.911	0.804	0.546–1.19	41	0.106	1.50	1.05–2.12	χ2 = 8.6 P = 0.072
	≥18.5 and <22.5	209		ref.		152		ref.
	≥22.5	70		0.857	0.650–1.13	55		0.902	0.659–1.23

BMI, body mass index; CI, confidence interval.