Table 3.

Multiple regression model for mtDNA copy number for DOX alone versus DEX+DOX

Variable	Coefficient (β)	SE	P-value
Intercept	2.60	0.28	<0.001
Treatment (DOX alone versus DEX+DOX)	0.46	0.13	0.001
Sex (male versus female)	0.11	0.14	0.45
Agea (<10 versus ≥10 years)	0.02	0.14	0.89
Immunophenotype (B-cell versus T-cell)	-0.18	0.21	0.41
RBC contamination (no versus yes)	0.02	0.14	0.89
Initial WBC	-0.0006	0.001	0.60

^aAge at the time of protocol registration.

DOX, doxorubicin; DEX, dexrazoxane; DEX+DOX, administration of dexrazoxane prior to every doxorubicin treatment; RBC, red blood cell; SE, standard error; WBC, white blood cell count.