Table 3.

Interaction analysis quantifying the association of preoperative anemia and perioperative allogeneic blood transfusion on primary and secondary outcomes

	Compound complications	Major complications	Minor complications	LOS (days)	ICU care >24 h
No anemia + 1–2 ABT	1.78 (1.08–2.91), p = 0.021	2.30 (1.12–4.68), p = 0.021	1.51 (0.80–2.77), p = 0.188	2.44 (1.84–3.24), p < 0.001	6.29 (2.31–19.92), p = 0.001
No anemia + >2 ABT	6.60 (4.34–10.13), p < 0.001	9.46 (5.34–17.46), p < 0.001	5.45 (3.31–9.09), p < 0.001	6.25 (4.48–8.80), p < 0.001	27.93 (11.82–92.19), p < 0.001
Mild anemia + No ABT	1.93 (0.85–3.94), p < 0.090	2.67 (0.86–6.96), p = 0.061	2.21 (0.87–4.95), p = 0.062	1.51 (0.93–2.41), p = 0.088	7.28 (1.77–28.07), p = 0.004
Mild anemia + 1–2 ABT	2.76 (1.34–5.33), p = 0.004	3.94 (1.48–9.45), p = 0.003	2.27 (0.89–5.09), p = 0.062	2.03 (1.27–3.24), p = 0.003	11.51 (3.39–40.82), p < 0.001
Mild Anemia + >2 ABT	10.13 (6.26–16.46), p < 0.001	13.53 (7.22–26.10), p < 0.001	11.83 (6.96–20.34), p < 0.001	9.63 (6.04–15.95), p < 0.001	48.97 (20.13–146.62), p < 0.001
Moderate anemia + No ABT	4.88 (1.54–13.15), p = 0.003	0.00a (0.00–0.00)	7.39 (2.29–20.39), p < 0.001	1.77 (0.71–4.24), p = 0.204	0.00a (0.00–0.00)
Moderate anemia + 1–2 ABT	6.91 (3.66–12.76), p < 0.001	5.23 (1.95–12.68), p < 0.001	8.23 (4.10–16.10), p < 0.001	3.49 (2.06–6.00), p < 0.001	9.79 (2.37–37.99), p = 0.001
Moderate anemia + >2 ABT	15.81 (10.39–24.41), p < 0.001	14.84 (8.42–27.35), p < 0.001	16.99 (10.66–27.74), p < 0.001	13.09 (8.57–20.71), p < 0.001	55.91 (24.01–163.22), p < 0.001

Numbers are given as odds ratio with a 95% confidence interval and p-value, with no anemia and no ABT as the reference. ABT numbers are given for units.

ABT, allogeneic blood transfusion.

^aNo patient in this category.