Comparison 5. Sensitivity analyses.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Fixed‐effect analysis of hazard ratios	10	2122	Hazard ratio (Fixed, 95% CI)	0.87 [0.81, 0.94]
2 Study quality	10	2122	Hazard ratio (Random, 95% CI)	0.88 [0.80, 0.96]
2.1 Jadad ≤ 3	8	853	Hazard ratio (Random, 95% CI)	0.85 [0.78, 0.93]
2.2 Jadad > 3	2	1269	Hazard ratio (Random, 95% CI)	0.94 [0.74, 1.19]
3 Postoperative chemotherapy	10	2122	Hazard ratio (Random, 95% CI)	0.88 [0.80, 0.96]
3.1 No postoperative chemotherapy	6	1301	Hazard ratio (Random, 95% CI)	0.85 [0.76, 0.96]
3.2 Postoperative chemotherapy	4	821	Hazard ratio (Random, 95% CI)	0.91 [0.79, 1.06]
4 Trial date	10	2122	Hazard ratio (Random, 95% CI)	0.88 [0.80, 0.96]
4.1 Before 1990	4	219	Hazard ratio (Random, 95% CI)	1.04 [0.78, 1.40]
4.2 1990 or later	6	1903	Hazard ratio (Random, 95% CI)	0.86 [0.78, 0.95]
5 Adenocarcinoma vs squamous cell	10		Hazard ratio (Random, 95% CI)	0.88 [0.80, 0.96]
5.1 Jadad ≤ 3	7		Hazard ratio (Random, 95% CI)	0.85 [0.74, 0.98]
5.2 Jadad > 3	3		Hazard ratio (Random, 95% CI)	0.90 [0.79, 1.03]