Two‐stage meta‐analysis based on random‐effects Cox model	ESA versus control HR (95% CI)	P value	N included
Chemotherapy trials
Analysis restricted to studies reporting chemotherapy status of each patient during ESA study	1.08 (0.95‐1.24)	0.242	8732
Analysis restricted to patients who actually received chemotherapy (subsets included: “chemotherapy”)	1.10 (0.96‐1.27)	0.172	8481
Analysis restricted to patients who actually received chemotherapy AND ESA in active arm AND no ESA in control arm (subsets included: “chemotherapy”)	1.09 (0.94‐1.26)	0.257	8114
Chemotherapy and mixed trials
Analysis restricted to studies reporting chemotherapy status of each patient during ESA study	1.09 (0.96‐1.25)	0.199	8998
Analysis restricted to patients who actually received chemotherapy (subsets included: “chemotherapy” and “mixed”)	1.12 (0.97‐1.28)	0.112	8651
Analysis restricted to patients who actually received chemotherapy AND ESA in active arm AND no ESA in control arm (subsets included: “chemotherapy” and “mixed”)	1.10 (0.96‐1.27)	0.173	8284
Chemotherapy, mixed and radiochemotherapy trials
Analysis restricted to studies reporting chemotherapy status of each patient during ESA study	1.11 (0.96‐1.27)	0.153	9661
Analysis restricted to patients who actually received chemotherapy (subsets: “chemotherapy”, “mixed” and “radiochemotherapy”)	1.14 (1.00‐1.30)	0.051	9307
Analysis restricted to patients who actually received chemotherapy AND ESA in active arm AND no ESA in control arm (subsets included: “chemotherapy”, “mixed” “radiochemotherapy”)	1.12 (0.98‐1.28)	0.101	8919