Skip to main content

Table 2 Patient demographics and preoperative characteristics

From: Establishment and assessment of a nomogram for predicting blood transfusion risk in posterior lumbar spinal fusion

  Total Not transfused Transfused P value
Number of patients 885 596 289  
Age (years)     0.038
 < 60 339 (38.31%) 249 (41.78%) 90 (31.14%)  
60 546 (61.69%) 347 (58.22%) 199 (68.86%)  
Gender (%)     0.312
 Male 440 (49.718%) 315 (52.852%) 125 (43.253%)  
 Female 445 (50.282%) 281 (47.148%) 164 (56.747%)  
Comorbidities     0.057
 None (%) 135 (15.254%) 93 (15.604%) 42 (14.533%)  
 1–3 (%) 543 (61.356%) 352 (59.060%) 191 (66.090%)  
4 (%) 207 (23.390%) 151 (25.336%) 56 (19.377%)  
BMI (kg/m2) 28.8 [26.6, 31.0] 28.6 [26.4, 30.7] 29.6 [26.9, 32.1] 0.001
Smoker (%)     0.323
 Yes 256 (28.927%) 79 (13.255%) 177 (61.246%)  
 No 629 (71.073%) 517 (86.745%) 112 (38.754%)  
ASA class (%)     < 0.001
 1 57 (6.441%) 49 (8.221%) 8 (2.768%)  
 2 504 (56.949%) 351 (58.893%) 153 (52.941%)  
 3 316 (35.706%) 192 (32.215%) 124 (42.907%)  
 4 8 (0.904%) 4 (0.671%) 4 (1.384%)  
Levels of fusion (%)     < 0.001
 1 344 (38.870%) 301 (50.503%) 43 (14.879%)  
 2 184 (20.791%) 146 (24.497%) 38 (13.149%)  
3 357 (40.339%) 149 (25.000%) 208 (71.972%)  
Time to surgery (days) 5.4 [4.6, 6.5] 5.1 [4.3, 5.8] 6.5 [5.4, 7.7] < 0.001
Total intraoperative EBL (ml) 357.9 [273.3, 512.0] 320.3 [238.3, 390.7] 857.3 [422.4, 956.1] < 0.001
Operative time (min) 191.2 [154.3, 235.9] 181.0 [150.1, 210.5] 249.4 [176.7, 344.0] < 0.001
Previous transfusion (%)     0.023
 Yes 24 (2.712%) 11 (1.846%) 13 (4.498%)  
 No 861 (97.288%) 585 (98.154%) 276 (95.502%)  
Previous surgery (%)     0.211
 Yes 74 (8.362%) 45 (7.550%) 29 (10.035%)  
 No 811 (91.638%) 551 (92.450%) 260 (89.965%)  
Preoperative APTT 31.4 [29.9, 33.0] 31.3 [29.9, 32.9] 31.6 [29.8, 33.6] 0.091
Preoperative PT 11.9 [11.1, 12.9] 12.1 [11.2, 13.1] 11.5 [10.8, 12.4] < 0.001
Preoperative fibrinogen 3.2 [2.7, 3.7] 3.2 [2.7, 3.7] 3.2 [2.6, 3.7] 0.630
Preoperative platelet count 249.9 [211.3, 297.5] 248.3 [209.3, 298.9] 253.7 [214.8, 293.6] 0.861
Preoperative hematocrit 35.5 [32.9, 37.8] 36.4 [34.1, 38.6] 33.2 [31.0, 35.9] < 0.001
Preoperative Hb 113.3 [106.2, 121.7] 115.5 [107.9, 126.2] 109.9 [104.2, 114.8] < 0.001
Preoperative WBC 7.21 [5.6, 8.7] 7.2 [5.5, 8.6] 7.3 [5.7, 8.7] 0.733
LOS 9.12[5.6, 8.7] 7.13[4.90, 9.36] 11.77[6.93, 15.61] < 0.001
  1. BMI Body mass index, ASA American Stroke Association, EBL Estimated blood loss, APTT Activated partial thromboplastin time, PT Prothrombin time, HB Hemoglobin, WBC White blood cell count, LOS Length of stay