Table 1 Baseline characteristics of the study sample

Age (mean ± SD)

82.2 ± 7.8

84.0 ± 8.8

81.6 ± 7.9

85.3 ± 8.7

0.2

Sex (female)

27 (54.0%)

37 (53.6%)

25 (56.8%)

17 (48.6%)

0.9

Fracture type

0.07

 Femoral neck

25 (50.0%)

29 (42.0%)

14 (31.8%)

20 (57.1%)

 Pertrochanteric

23 (46.0%)

37 (53.6%)

19 (43.2%)

11 (31.4%)

 Subtrochanteric

2 (4.0%)

3 (4.3%)

11 (25.0%)

4 (11.4%)

Procedure

0.12

 Arthroplasty

16 (35.6%)

20 (30.3%)

16 (37.2%)

5 (14.7%)

 Gamma nail

23 (51.1%)

39 (59.1%)

26 (60.5%)

27 (79.4%)

 Dynamic hip screws

4 (8.9%)

4 (6.1%)

1 (2.3%)

1 (2.9%)

 AO screws

2 (4.4%)

3 (4.5%)

0 (0.0%)

1 (2.9%)

 Others

5 (10.0%)

3 (4.3%)

1 (2.3%)

1 (2.9%)

BMI (mean ± SD)

24.3 ± 4.5

24.4 ± 3.9

24.6 ± 4.8

22.5 ± 3.4

0.1

Missing

0

0

1

0

Charlson comorbidity index

 0

18 (36.0%)

19 (27.5%)

8 (18.2%)

8 (22.9%)

 1

10 (20.0%)

24 (34.8%)

6 (13.6%)

9 (23.4%)

 2

5 (10.0%)

11 (15.9%)

12 (27.3%)

3 (8.6%)

  ≥ 3

17 (24.0%)

15 (21.7%)

18 (40.9%)

15 (42.9%)

0.03

Polypharmacy

36 (72.0%)

46 (66.7%)

40 (90.9%)

31 (88.6%)

0.006

Anticoagulant treatment

10 (20.0%)

13 (18.8%)

13 (29.5%)

11 (31.4%)

CAS score admission (median (IQR))

6 (6, 6)

6 (6, 6)

6 (6, 6)

6 (6, 6)

0.7

Missing

1

0

2

1

CAS score discharge (median (IQR))

4 (3, 6)

4 (3, 5)

3 (2, 5)

3 (2, 5)

0.4

Missing

1

0

3

1

Length of stay (days) (median (IQR))

5 (4, 6)

5 (4, 6)

6 (4, 8)

6 (6, 8)

0.03

Number of transfusions^a (median (IQR))

0 (0, 0)

0 (0, 0)

2 (2, 3)

2 (2, 3)

 < 0.001

Hgb at day 3 postoperatively (mmol/L) (median (IQR))

5.8 (5.4, 6.1)

5.8 (5.4, 6.1)

5.3 (4.7, 5.8)

5.4 (4.8, 5.9)

0.002