Table 4 Individual background factors and risk of first incident fracture in the multivariable-adjusted model

Age at baseline

(years)

1.07

1.06–1.07

< 0.001

Body mass index (BMI)

(kg/m²)

0.95

0.94–0.97

< 0.001

Previous fracture

(yes)

1.64

1.43–1.88

< 0.001

Current smoking

(yes)

1.12

1.04–1.20

0.003

Living alone

(yes)

1.03

0.96–1.10

0.44

Family history of fractures

(yes)

1.12

1.05–1.20

0.001

Weight at baseline

(kg)

1.01

1.01–1.02

0.001

 It has been the same

Reference

 Gradually increased

0.99

0.90–1.10

0.897

 Gradually decreased

1.39

1.17–1.65

< 0.001

 My weight has varied

1.07

0.96–1.19

0.22

Alcohol

(g/day)

 Quartile 1 (0–0.80)

Reference

 Quartile 2 (0.81–5.35)

0.96

0.88–1.04

0.285

 Quartile 3 (5.36–11.42)

0.88

0.81–0.96

0.002

 Quartile 4 (> 11.43)

0.96

0.88–1.05

0.346

 no children

Reference

 1–2 children

0.99

0.86–1.14

0.902

  ≥ 3 children

1.02

0.88–1.19

0.782

Total duration of lactation

(months)

 no lactation

Reference

 1–6

0.96

0.85–1.09

0.554

 7–18

0.97

0.86–1.09

0.586

  ≥ 19

0.94

0.80–1.10

0.434

Age at menopause

(years)

  < 40

1.06

0.91–1.24

0.439

 40–44

1.14

1.03–1.27

0.009

 45–54

Reference

  > 55

0.97

0.88–1.07

0.501