Table 2.

The subgroup analysis of prognostic role of SII for OS in OC.

Subgroups	No. of studies	No. of patients	Effects model	HR (95%CI)	p	Heterogeneity I2 (%) Ph
Total	5	1,438	FEM	2.70 (1.98-3.67)	<0.001	36.3	0.179
Country
China	2	655	REM	3.85 (1.68-8.82)	0.001	62.0	0.105
Italy	2	734	FEM	1.94 (1.05-3.60)	0.036	31.6	0.227
India	1	49	–	2.49 (1.43-4.34)	0.001	–	–
Sample size
<200	2	151	FEM	2.59 (1.76-3.83)	<0.001	0	0.838
≥200	3	1,287	REM	3.27 (1.27-8.46)	0.014	67.4	0.046
Treatment
Chemotherapy	2	424	FEM	2.09 (1.36-3.23)	0.001	0	0.324
Surgery	2	912	FEM	5.54 (2.66-11.55)	<0.001	0	0.576
Surgery + chemotherapy	1	102	–	2.70 (1.57-4.65)	<0.001	–	–
Study center
Single center	4	1,063	FEM	3.06 (2.17-4.32)	<0.001	15.6	0.314
Multicenter	1	375	–	1.59 (0.79-3.20)	0.193	–	–
Cut-off value
<720	2	602	REM	3.73 (1.50-9.27)	0.005	68.0	0.077
≥720	3	836	FEM	2.34 (1.55-3.52)	<0.001	3.8	0.354

OS, overall survival; SII, systemic immune-inflammation index; OC, ovarian cancer; FEM, fixed-effects model; REM, random-effects model.

"-" means blank.