Table 3 Multivariable analysis to assess the effect of preoperative hemoglobin level on prolonged LOS (> 13 days) among patients who underwent orthopedic surgery atTibebe Ghion Specialized Hospital, Northwest Ethiopia

Preoperative hemoglobin level (mg/dl)^a

11.20 (± 2.44)

10.32 (± 2.43)

0.83 (0.77, 0.90)*

Age (in years)^b

30 (23, 45)

32 (25, 50)

1.00 (0.99, 1.01)

Sex

Male

565 (75.64)

171 (80.66)

1, ref

Female

182 (24.36)

41 (19.34)

0.75 (0.50, 1.14)

ASA

I/II

723 (96.79)

199 (93.87)

1, ref

III/IV

24 (3.21)

13 (6.13)

0.69 (0.26, 1.81)

Comorbidity

Yes

117 (15.66)

52 (24.53)

2.28 (1.34, 3.87)*

No

630 (84.34)

160 (75.47)

1, ref

Urgency of surgery

Elective

330 (44.18)

74 (34.91)

1, ref

Emergency

417 (55.82)

138 (65.09)

1.11 (0.78, 1.58)

Trauma

Yes

533 (71.35)

153 (72.17)

1.15 (0.78, 1.68)

No

214 (28.65)

59 (27.83)

1, ref

Type of anesthesia

General

130 (17.40)

40 (18.87)

0.90 (0.58, 1.39)

Regional

617 (82.60)

172 (81.13)

1, ref

Length of surgery

 < 2 h

540 (72.29)

145 (68.40)

1, ref

 ≥ 2 h

207 (27.71)

67 (31.60)

0.97 (0.65, 1.44)

Bloss loss

 < 500

657 (87.95)

165 (77.83)

1, ref

 ≥ 500

90 (12.05)

47 (22.17)

1.69 (0.95, 3.01)

Blood transfusion

Yes

82 (10.98)

29 (13.68)

0.72 (0.38, 1.37)

No

665 (89.02)

183 (86.32)

1, ref