Comparison 2. Subgroup analysis (cisplatin dose: 40 to 79 mg/m² versus 80 to 100 mg/m²).

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Overall survival	9		Hazard Ratio (Random, 95% CI)	Subtotals only
1.1 40 to 80 mg/m2	6	2508	Hazard Ratio (Random, 95% CI)	1.15 [1.03, 1.28]
1.2 80 to 100 mg/m2	4	1823	Hazard Ratio (Random, 95% CI)	0.93 [0.83, 1.04]
2 1‐year survival rate	10		Risk Ratio (M‐H, Random, 95% CI)	Subtotals only
2.1 40 to 80 mg/m2	6	2508	Risk Ratio (M‐H, Random, 95% CI)	1.04 [0.85, 1.27]
2.2 80 to 100 mg/m2	5	1949	Risk Ratio (M‐H, Random, 95% CI)	0.96 [0.86, 1.08]
3 Response rate	11		Risk Ratio (M‐H, Random, 95% CI)	Subtotals only
3.1 40 to 80 mg/m2	7	2524	Risk Ratio (M‐H, Random, 95% CI)	0.94 [0.74, 1.20]
3.2 80 to 100 mg/m2	5	1949	Risk Ratio (M‐H, Random, 95% CI)	0.89 [0.77, 1.02]