Table 2:

Results of subgroup analysis

Parameters	End Point	Factor	No. of Studies	HR	95% CI of HR	P Value	I² (%)	Model
TNR	OS	Tumor grade (high)	7	1.76	1.36–2.28	<.001^{^a}	22	Fixed
TNR	OS	Tumor grade (low)	6	2.19	0.98–4.86	.05^{^b}	97	Random
TNR	OS	Tumor stage (primary)	9	1.95	1.45–2.63	<.001^{^a}	55	Random
TNR	OS	Tumor stage (recurrence)	2	2.58	1.31–5.08	.006^{^a}	0	Fixed
TNR	OS	Calculation method of TNR (tumor SUVmax/normal contralateral SUVmean)	8	1.97	1.42–2.74	<.001^{^a}	60	Random
TNR	OS	Calculation method of TNR (others)	3	2.15	1.29–3.60	.003^{^a}	0	Fixed
MTV	OS	Tumor grade (high)	2	5.54	3.11–9.86	<.001^{^a}	0	Fixed
MTV	OS	Tumor stage (primary)	2	3.51	1.04–11.88	.04^{^a}	85	Random
MTV	OS	Reference for MTV (1.3 × SUVmean of normal contralateral cortex)	2	3.51	1.04–11.88	.04^{^a}	85	Random

↵a Statistically significant (P < .05).
↵b Significant trend (.05 ≤ P ≤ .10).