. 2023 Jun 20;20(9):3884–3897. doi: 10.1111/iwj.14264

TABLE 3.

The main outcomes of the meta‐analysis.

Significant factors		No. of studies	I ² (%)	Q test (P)	OR (95% CI)	P value
General factors	Sex	13 ¹⁵ , ¹⁷ , ¹⁸ , ¹⁹ , ²⁰ , ²¹ , ²² , ²³ , ²⁴ , ²⁶ , ²⁷ , ²⁸ , ²⁹	12	0.32	1.28 (1.06, 1.55)	.01 ^a
	Age > 60	2 ²⁰ , ²⁸	0	0.53	2.75 (1.65, 4.57)	.0001 ^a
	Smoking	5 ¹⁵ , ¹⁶ , ¹⁸ , ²³ , ²⁷	47	0.11	1.99 (1.46, 2.73)	<.0001 ^a
Diseases factors	Hypertension	6 ¹⁵ , ¹⁹ , ²³ , ²⁴ , ²⁷ , ²⁹	0	0.71	1.24 (0.94, 1.64)	.12 ^a
	Diabetes	9 ¹⁵ , ¹⁹ , ²⁰ , ²² , ²³ , ²⁴ , ²⁷ , ²⁸ , ²⁹	12	0.33	2.03 (1.59, 2.61)	<.00001 ^a
	Anaemia	3 ¹⁵ , ²² , ²⁹	58	0.09	4.72 (1.66, 13.40)	.004 ^b
	Preoperative obstruction	2 ²² , ²⁸	0	0.99	3.07 (1.80, 5.23)	<.0001 ^a
	TNM ≥ III	5 ¹⁵ , ¹⁸ , ¹⁹ , ²⁰ , ²³	24	0.26	2.05 (1.56, 2.70)	<.00001 ^a
	Hypoproteinemia	5 ¹⁵ , ¹⁸ , ¹⁹ , ²² , ²⁷	0	0.52	3.05 (2.08, 4.49)	<.00001 ^a
Surgical operation factors	ASA ≥ 3	5 ²¹ , ²⁴ , ²⁷ , ²⁸ , ²⁹	0	0.78	1.22 (0.87, 1.72)	.25 ^a
	Operation time ≥3 h	2 ²⁴ , ²⁵	0	0.39	8.33 (3.81, 18.20)	<.00001 ^a
	Surgery ways	6 ¹⁵ , ²¹ , ²³ , ²⁴ , ²⁷ , ²⁹	0	0.74	2.18 (1.61, 2.94)	<.00001 ^a
	Blood transfusion	3 ¹⁹ , ²⁰ , ²⁴	38	0.20	1.44 (1.01, 2.06)	.04 ^a

Note: I ² statistic was defined as the proportion of heterogeneity not due to chance or random error. The significance of statistics is shown in bold.

Abbreviations: ASA, American Society of Anesthesiologists; CI, confidence interval; OR, odds ratio; TNM, distant staging of local lymph node metastasis of primary tumour.

^{^a}

Fixed‐effects model was performed.

^{^b}

Random‐effects model was performed.