Study	Reason for exclusion
EBMTR	Insufficient information on baseline characteristics (less than 5 factors without substantial missing data). Insufficient information on treatment plan, already apparent imbalances between use of TBI in the "planned" or "unplanned" group.
Kim 2009	No separate information on patients receiving either one or two transplants.
Koren 2010	No separate information on patients receiving either one or two transplants.
Lahuerta 2003	No separate information on patients receiving either one or two transplants.
NMSG	Insufficient information on baseline characteristics (less than 5 factors). Insufficient information on treatment plan.
Sonneveld 2007	Non‐myeloablative dosing regimen of melphalan (2 x 70 mg/m²).
Total therapy	No RCT. No contemporary control group. Of note: integration of novel agents in TT generation >1 is regarded as a critically different treatment approach compared to the set of included RCTs.