Table 3. Mean perioperative outcomes of the study groups .

1 Level	OLLIF	TLIF	p value
Blood loss (ml)	33.9±17.2	355.0±131.5	<0.001
Surgery time (min)	62.9±29.4	134.9±21.7	<0.001
Days to discharge	2.6±1.7	4.2±1.2	0.001
2 Level	OLLIF	TLIF	p value
Blood loss (ml)	55.4±78.4	452.6±327.6	<0.001
Surgery time (min)	70.5±42.0	175.3±39.3	<0.001
Days to discharge	3.3±1.1	5.8±6.5	0.010
3 Level	OLLIF	TLIF	p value
Blood loss (ml)	94.2±57.6	618.6±353.9	<0.001
Surgery time (min)	114.2±42.9	213.7±40.5	<0.001
Days to discharge	3.2±2.2	4.3±1.3	0.940
4 Level	OLLIF	TLIF	p value
Blood loss (ml)	102.3±66.1	589.4±255.3	0.009
Surgery time (min)	161.8±25.8	250.2±73.6	0.020
Days to discharge	4.6±0.6	6.7±1.6	0.011