Table 4 Linear regression model to identify factors potentially associated with age at menopause.

Education

 Primary

1.00 (ref.)

1.00 (ref.)

 Secondary

−1.34

−2.06, −0.62

0.59

−0.11, 1.30

0.10

 Higher

−4.41

−8.83, 0.01

−2.67

−7.08, 1.74

0.23

Employment

 Housewife

1.00 (ref.)

1.00 (ref.)

 Employed

−1.27

−1.87, −0.66

−0.32

−0.91, 0.26

0.27

Marital status

 Single

1.00 (ref.)

1.00 (ref.)

 Married

0.84

−1.25, −0.42

0.06

−0.49, 0.62

0.81

Smoking

 Yes

1.00 (ref.)

1.00 (ref.)

 No

1.23

0.44, 2.01

0.15

−0.58, 0.88

0.68

‌Breast cancer

 Yes

1.00 (ref.)

1.00 (ref.)

 No

4.74

0.62, 8.48

2.79

−1.23, 6.83

0.17

Hypertension

 Yes

1.00 (ref.)

1.00 (ref.)

 No

1.76

2.24, 1.27

0.84

0.34, 1.35

0.001

Thyroid disease

 Yes

1.00 (ref.)

1.00 (ref.)

 No

0.76

0.04, 1.49

0.75

0.07, 1.43

0.02

Diabetes

 Yes

1.00 (ref.)

1.00 (ref.)

 No

−0.5

−1.07, 0.06

−0.007

−0.54.0.53

0.97

CVA

 Yes

1.00 (ref.)

1.00 (ref.)

 No

0.9

0.50, 1.31

0.54

−0.03, 1.13

0.06

Rheumatic disease

 Yes

1.00 (ref.)

–

–

–

 No

0.51

−0.29, 1.31

–

–

–

Infertility

Yes

1.00 (ref.)

1.00 (ref.)

No

−0.37

−0.93, 0.17

−0.25

−0.78, 0.27

0.34

OCP

Yes

1.00 (ref.)

1.00 (ref.)

No

−0.38

−0.87, 0.10

0.16

−0.31, 0.65

0.49

Tubectomy

Yes

1.00 (ref.)

–

–

–

No

0.009

−0.49, 0.50

–

–

–

Age (y)

0.34

0.31, 0.38

0.29

0.24, 0.33

< 0.001

Marriage age

0.03

0.000, 0.07

0.01

−0.03, 0.05

0.62

Age at first birth (y)

0.05

0.02, 0.11

0.11

0.05, 0.17

< 0.001

Gravidity

0.38

0.31, 0.45

0.06

−0.25, 0.38

0.70

Number of live births

0.44

0.36, 0.52

0.18

−0.14, 0.51

0.27

Number of abortions

0.29

0.02, 0.56

−0.19

−0.59, 0.21

0.35

BMI

−0.01

−0.06, 0.04

–

–

–

Menarche age

0.29

0.05, 0.33

0.06

−0.06, 0.20

0.33