Table 3. Subgroup analysis of the effect of intensive follow-up on overall survival.

Subgroup title	Trial	I2	HR (95% CI)	P
Intensive follow-up strategy
Intensive frequency	4	17%	0.82 [0.69, 0.97]	0.04
Intensive test	4	0%	1.07 [0.88, 1.31]
Frequency of follow-up
Short interval(≤3 months)	9	11%	0.75 [0.64, 0.87]	0.02
Long interval (>3 months)	4	0%	0.96 [0.84, 1.11]
Using CEA
CEA	5	0%	0.97 [0.84, 1.13]	0.66
No CEA	1	-	0.90 [0.67, 1.21]
Using CT
CT	7	0	0.93 [0.82, 1.06]	0.57
No CT	2	53%	1.31 [0.40, 4.23]