Table 2 Postoperative anemia of THA: Univariate and multivariate analysis of possible risk factors in the training cohort

Age (years)

1.026 (1.012–1.039)

 < 0.001

0.984 (0.964–1.005)

0.127

BMI (kg/m²)

0.861 (0.812–0.913)

 < 0.001

0.903 (0.840–0.970)

0.005

Sex

 Male

1

1

 Female

1.631 (1.068–2.492)

0.024

0.878 (0.482–1.600)

0.671

Reasons of operation

 FNF

1

 ONFN

1.420 (0.967–2.084)

0.074

 OAH

1.030 (0.666–1.593)

0.895

 Operation time (min)

1.011 (1.005–1.016)

 < 0.001

1.011 (1.003–1.018)

0.006

 Intraoperative blood loss (mL)

1.002 (1.001–1.004)

0.002

1.003 (1.000–1.005)

0.017

Type of anesthesia

 GA

1

 CSEA

1.291 (0.937–1.798)

0.117

Smoking

 No

1

 Yes

1.458 (0.923–2.303)

0.106

Drinking

 No

1

 Yes

1.202 (0.748–1.932)

0.447

Hypertension

 No

1

1

 Yes

1.915 (1.370–2.678)

 < 0.001

1.400 (0.873–2.245)

0.163

Diabetes

 No

1

1

 Yes

1.497 (1.013–2.212)

0.043

1.371 (0.801–2.347)

0.249

Cardiovascular disease

 No

1

 Yes

1.239 (0.759–2.022)

0.391

Cerebrovascular disease

 No

1

1

 Yes

3.780 (2.410–5.928)

 < 0.001

2.485 (1.369–4.514)

0.003

Osteoporosis

 No

1

1

 Yes

3.13 (2.227–4.398)

 < 0.001

2.273 (1.464–3.529)

 < 0.001

TP (g/L)

0.958 (0.936–0.980)

 < 0.001

1.004 (0.960–1.050)

0.868

ALB (g/L)

0.930 (0.899–0.963)

 < 0.001

1.118 (1.038–1.205)

0.003

GLB (g/L)

0.982 (0.951–1.014)

0.268

SAA (mg/L)

1.004 (1.002–1.006)

 < 0.001

1.003 (1.001–1.005)

0.014

IRON (μmol/L)

1.005 (0.991–1.018)

0.499

TIBC (μmol/L)

0.972 (0.954–0.990)

0.002

0.991 (0.966–1.018)

0.517

CRP (mg/L)

1.003 (0.999–1.008)

0.162

RBC (1,012/L)

0.208 (0.152–0.286)

 < 0.001

0.842 (0.386–1.839)

0.666

HB (g/L)

0.935 (0.924–0.947)

 < 0.001

0.936 (0.894–0.980)

0.005

HCT (%)

0.830 (0.800–0.861)

 < 0.001

0.972 (0.860–1.099)

0.952

MCV (fL)

1.010 (0.984–1.037)

0.436

MCH (pg)

0.988 (0.923–1.057)

0.724

MCHC (g/L)

0.971 (0.954–0.988)

0.001

0.979 (0.951–1.009)

0.164