Table 3 Results of the generalized estimating equation model without and with adjustment of demographic characteristics*

Six-month

Two-year

Six-month

Two-year

SF-36

   Physical functioning

22.5 (1.65)

< 0.0001

26.7 (2.09)

< 0.0001

22.8 (1.95)

< 0.0001

27.3 (2.51)

< 0.0001

   Role physical

32.9 (3.37)

< 0.0001

28.7 (4.45)

< 0.0001

35.9 (4.00)

< 0.0001

26.8 (5.40)

< 0.0001

   Bodily pain

6.04 (1.46)

0.0003

-0.57 (1.56)

0.7100

4.48 (1.72)

0.0093

-1.41 (1.96)

0.4715

   General health

0.12 (0.81)

0.8800

-4.13 (0.90)

< 0.0001

0.34 (1.01)

0.7336

-4.23 (1.16)

0.0003

   Role emotional

15.6 (2.60)

< 0.0001

12.2 (3.20)

0.0001

15.9 (3.37)

< 0.0001

12.9 (3.96)

0.0011

   Social functioning

1.54 (1.28)

0.2310

-1.52 (1.22)

0.2120

0.81 (1.76)

0.6466

-2.52 (1.72)

0.1431

   Vitality

-0.202 (1.21)

0.8670

-0.584 (1.33)

0.0600

-1.08 (1.53)

0.4819

0.15 (1.74)

0.9294

   Mental health

1.18 (0.93)

0.2050

0.57 (0.95)

0.5510

2.04 (1.09)

0.0613

-0.07 (1.28)

0.9569

OKS

28.5 (1.22)

< 0.0001

33.4 (22.6)

< 0.0001

28.8 (1.56)

< 0.0001

32.4 (1.74)

< 0.0001

KSS

   Knee

37.5 (1.32)

< 0.0001

41.3 (1.55)

< 0.0001

37.0 (1.68)

< 0.0001

40.4 (2.12)

< 0.0001

   Functioning

16.2 (1.52)

< 0.0001

20.9 (1.90)

< 0.0001

15.8 (1.79)

< 0.0001

19.4 (2.27)

< 0.0001