Table 3. Subgroup analysis.

Outcomes	Group	OR and 95%CI	P value	Heterogeneity (%)	P value for heterogeneity	P value for heterogeneity between subgroups
30-day survival rate	Publication year
	2005 or after	1.48(0.78–2.78)	0.228	0.0	0.798	0.674
	Before 2005	1.91(0.70–5.22)	0.210	0.0	0.905
	Study design
	Prospective	1.86(0.87–3.96)	0.108	0.0	0.723	0.562
	Retrospective	1.35(0.63–2.89)	0.436	0.0	0.947
	Sample size
	100 or larger	2.06(0.89–4.77)	0.090	0.0	0.767	0.424
	< 100	1.32(0.66–2.65)	0.433	0.0	0.947
	Mean age (years)
	60 or older	1.43(0.78–2.61)	0.250	0.0	0.878	0.456
	< 60	2.34(0.74–7.46)	0.149	0.0	0.972
	Percentage male (%)
	50 or larger	1.55(0.86–2.81)	0.147	0.0	0.933	0.877
	<50	1.74(0.51–5.99)	0.378	0.0	0.469
10-month survival rate	Publication year
	2005 or after	1.22(0.77–1.93)	0.398	14.4	0.322	1.000
	Before 2005	1.06(0.25–4.54)	0.938	74.3	0.009
	Study design
	Prospective	1.17(0.77–1.79)	0.457	10.6	0.340	1.000
	Retrospective	1.28(0.34–4.81)	0.717	68.3	0.013
	Sample size
	100 or larger	1.32(0.85–2.05)	0.217	0.0	0.859	1.000
	< 100	1.18(0.53–2.65)	0.685	62.4	0.014
	Mean age (years)
	60 or older	0.96(0.45–2.05)	0.919	56.2	0.044	0.256
	< 60	1.91(0.80–4.59)	0.147	34.8	0.216
	Percentage male (%)
	50 or larger	1.13(0.58–2.22)	0.721	56.6	0.032	0.577
	<50	1.69(0.52–5.52)	0.386	38.5	0.202
20-month survival rate	Publication year
	2005 or after	1.74(0.95–3.18)	0.074	0.0	0.562	0.492
	Before 2005	2.49(1.09–5.68)	0.031	0.0	0.381
	Study design
	Prospective	1.81(0.53–6.18)	0.344	48.3	0.145	0.929
	Retrospective	1.94(1.07–3.50)	0.028	0.0	0.902
	Sample size
	100 or larger	1.71(0.76–3.87)	0.194	-	-	0.677
	< 100	2.13(1.16–3.92)	0.015	0.0	0.510
	Mean age (years)
	60 or older	1.74(0.95–3.18)	0.074	0.0	0.562	0.492
	< 60	2.49(1.09–5.68)	0.031	0.0	0.381
	Percentage male (%)
	50 or larger	1.93(1.12–3.31)	0.018	0.0	0.422	0.859
	<50	2.16(0.71–6.58)	0.177	0.0	0.465
30-month survival rate	Publication year
	2005 or after	1.33(0.76–2.32)	0.321	0.0	0.835	0.765
	Before 2005	1.10(0.36–3.36)	0.872	0.0	0.861
	Study design
	Prospective	1.12(0.32–3.89)	0.858	0.0	0.875	0.822
	Retrospective	1.31(0.76–2.26)	0.333	0.0	0.824
	Sample size
	100 or larger	1.23(0.65–2.35)	0.523	-	-	0.870
	< 100	1.34(0.61–2.97)	0.463	0.0	0.917
	Mean age (years)
	60 or older	1.33(0.76–2.32)	0.321	0.0	0.835	0.765
	< 60	1.10(0.36–3.36)	0.872	0.0	0.861
	Percentage male (%)
	50 or larger	1.22(0.71–2.08)	0.474	0.0	0.971	0.635
	<50	1.73(0.45–6.70)	0.426	0.0	0.473

*OR, odds ratio; CI, confidence interval