Table 5. Subgroup analysis of CR and 5-year OS.

Indicators	Subgroup	Meta regression	OR/HR 95% CI	p value	Heterogeneity (I2, %)	p value for heterogeneity
CR for RT versus RCT	CT regimen	0.09
	CHOP*		1.02 (0.57–1.82)	0.94	28.4	0.20
	non-CHOP		0.43 (0.06–3.10)	0.40	62.2	0.10
	Country A	0.02
	Asia		1.04 (0.61–1.78)	0.87	19.7	0.27
	Non-Asia		0.21 (0.11–0.40)	0.000	-	-
	Country B	0.43
	China		1.01 (0.48–2.14)	0.98	38.5	0.14
	Non-China		0.61 (0.15–2.54)	0.50	82.9	0.003
	Study design	0.02
	retrospective		1.04 (0.61–1.78)	0.87	19.7	0.27
	prospective		0.21 (0.11–0.40)	0.000	-	-
CR for RT versus CT	CT regimen	0.30
	CHOP*		10.73 (2.40–47.90)	0.002	48.0	0.09
	non-CHOP		1.94(1.12–3.35)	0.02	-	-
	Country A	0.67
	Asia		9.03 (1.72–47.41)	0.009	51.7	0.08
	Non-Asia		5.44 (0.35–84.77)	0.27	69.4	0.07
	Country B	0.67
	China		9.03 (1.72–47.41)	0.009	51.7	0.08
	Non-China		5.44 (0.35–84.77)	0.27	69.4	0.07
	Study design	0.30
	retrospective		10.73 (2.40–47.90)	0.002	48.0	0.09
	prospective		1.94(1.12–3.35)	0.02	-	-
CR for CT versus RCT	CT regimen	0.87
	CHOP*		0.15 (0.07–0.32)	0.000	0.0	0.50
	non-CHOP		0.13 (0.07–0.22)	0.000	28.3	0.25
	Country A	0.35
	Asia		0.19 (0.09–0.38)	0.000	5.7	0.38
	Non-Asia		0.10 (0.06–0.19)	0.000	0.0	0.79
	Country B	0.98
	China		0.15 (0.07–0.35)	0.000	5.0	0.38
	Non-China		0.12 (0.07–0.21)	0.000	0.0	0.41
	Study design	0.67
	retrospective		0.16(0.08–0.32)	0.000	0.0	0.49
	prospective		0.11(0.06–0.20)	0.000	-	-
5-year OS for RT versus RCT	CT regimen	-
	CHOP*		1.11(0.85–1.45)	0.428	42.5	0.095
	non-CHOP		-	-	-	-
	Country A	0.06
	Asia		1.06(0.82–1.39)	0.65	8.6	0.36
	Non-Asia		10.57(1.61–69.28)	0.01	-	-
	Country B	0.29
	China		1.29(0.93–1.79)	0.13	0.0	0.84
	Non-China		0.84(0.54–1.32)	0.45	76.5	0.01
	Study design	-
	retrospective		1.11(0.85–1.45)	0.428	42.5	0.095
	prospective		-	-	-	-

CR: complete remission; OS: overall survival; CT: chemotherapy; RT: radiotherapy; RCT: radiochemotherapy; CHOP cyclophosphamide, doxorubicin, vincristine, prednisone; CHOP* CHOP, CHOP-like or non-CHOP.