Table 2.

Results of subgroup analysis on overall survival.

Subgroup	No. of studies	Pooled hazard ratio	95% confidence interval	Heterogeneity between studies
Study design
Prospective	2	1.43	1.20–1.72	p = 0.107, I 2 = 61.5%
Retrospective	8	1.57	1.43–1.73	p = 0.508, I 2 = 0.0%
Sample size
<1,000	7	1.50	1.32–1.69	p = 0.438, I 2 = 0.0%
≥1,000	3	1.58	1.42–1.77	p = 0.184, I 2 = 40.9%
Prealbumin cutoff
≤18 mg/dl	7	1.54	1.41–1.69	p = 0.158, I 2 = 35.4%
>18 mg/dl	3	1.56	1.28–1.90	p = 0.824, I 2 = 0.0%
Follow-up duration
>36 months	8	1.58	1.44–1.73	p = 0.669, I 2 = 0.0%
≤36 months	2	1.42	1.19–1.71	p = 0.113, I 2 = 60.1%