Table 1 Descriptives of the study population (N = 6810), predictors, crude and adjusted odds ratios (OR) with 95% confidence intervals (95% CI)

Time

n.a.

0 month

n.a.

1.00

1.00

3 month

n.a

0.83 (0.77–0.88)

0.78 (0.72–0.84)

12 month

n.a

1.07 (1.00–1.15)

1.10 (1.02–1.19)

Age

65 (9)

22–54 years

1.00

1.00

55–64 years

0.75 (0.65–0.85)

0.74 (0.64–0.85)

65–74 years

0.50 (0.44–0.57)

0.47 (0.42–0.54)

75–100 year

0.78 (0.67–0.91)

0.64 (0.55–0.75)

Charnley category^a

n.a.

A

35

1.00

1.00

B

31

1.05 (0.94–1.17)

1.00 (0.90–1.11)

C

33

1.38 (1.25–1.53)

1.15 (1.04–1.28)

BMI

28 (5)

Normal weight

1.00

1.00

Overweight

1.39 (1.25–1.56)

1.27 (1.14–1.42

Obesity

2.36 (2.10–2.65)

1.93 (1.71–2.17)

Gender

n.a.

Man

27

1.00

1.00

Woman

73

0.80 (0.73–0.88)

0.69 (0.62–0.75)