TABLE 1.

The information about four traditional observational studies.

	Study	Population size	Type of adjustment	Main conclusion	E-value
Age at menarche	Roman Lay et al., 2020	232010	None	AAM ≥ 13 years was associated with a later ANM: HR = 0.90, 95%CI = 0.84, 0.96	1.36
Current smoking	Zhu et al., 2018	207231	Race/ethnicity/region, education level, and BMI	Never smoker: Reference current smokers: RR = 1.80, 95%CI = 1.66, 1.95	(i)3
Body mass index	Tao et al. (2015)	313482	None	Normal: Reference (i) Underweight: HR = 1.08, 95%CI = 1.03, 1.14 (ii) Overweight: HR = 0.93, 95%Cl = 0.91, 0.96 (iii) Obese: 0.95, 95Cl% = 0.79, 1,15	(i)1.3 (ii)1.28 (iii)1.23
Schooling years	Schoenaker et al., 2014	14620	Smoking, body mass index, physical activity and education	Low: Reference (i) Middle: HR = 0.93, 95%CI = 0.87, 0.98 (ii) High: HR = 0.81, 95%CI = 0.74, 0.89	(i)1.28 (ii)1.58