Table 2.

Risk of bias of included studies

Study ID	Blinding of assessment of overall mortality	Incomplete outcome data	Selective reporting	Other bias	Comparable baseline characteristics	Concurrent control	Overall judgement of bias
Bayever et al20	Low	Low	Unclear	High*	Low	Low	High
Führer et al22	Low	High	High†	High‡	Low	Low	High
Gratwohl et al21	Low	High	Unclear	Unclear	Low	Low	High

*Bayever et al²⁰: the authors reported the study results at an early time point before all planned data had been gathered: ‘We present this interim report (…)’.

†Führer et al²²: In the 2005 update, overall survival, secondary clonal disease or malignancies, and also relapse were not reported separately for the two distinct treatment groups. Rather, the results were presented for two subgroups according to disease severity. This was different from the earlier report of the same study published in 1998 covering the study period from 1993 to 1997. See figure 1 and table 1 of the article.

‡Führer et al²²: financial support was provided by two pharmaceutical companies.