The study included 2,300 people who got BMT for acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), or myelodysplastic syndromes (MDS). Everyone got BMT in the US during 2011-2018.
The study compared the medical records of people who got half-matched versus fully matched BMT. People who got a fully-matched BMT were less likely to get acute graft-versus-host disease (GVHD). GVHD is a serious complication of transplant.
In people who received less intense medicines (called reduced-intensity preparation), those had a matched donor lived longer than those who had a half-matched donor.