Table 3 The multivariate Cox regression analysis and the receiver operating characteristic curve between two groups

Sex

0.599(0.571–0.627)

 Female

 Male

75.449

42.863-132.807

4.323

< 0.001

Age (years)

1.045

1.032–1.058

0.044

< 0.001

0.554(0.525–0.582)

Occupation

0.484(0.455–0.514)

 Weight-Bearing

 Standing

0.887

0.615–1.280

-0.120

0.523

 Seatting

3.937

2.712–5.716

1.370

< 0.001

Haemoglobin (g/L)

0.909

0.897–0.922

-0.095

< 0.001

0.361(0.333–0.389)

Duration of disease (months)

1.217

1.169–1.267

0.196

< 0.001

0.642(0.614–0.669)

Aetiology

0.466(0.437–0.495)

 Alcohol-induced (ref.)

 Idiopathic

2.762

2.016–3.788

1.017

< 0.001

 Steroid-induced

2.543

1.852–3.685

0.853

< 0.001

The combined necrosis angle

1.025

1.022–1.028

0.024

< 0.001

0.775(0.751–0.798)