CYP indicates cytochrome P450; EM, extensive metabolism (ie, patients with 2 functional alleles, including patients with ultrarapid metabolism); hetEM/IM, patients with intermediate or 1 poor metabolism allele; PM, patients homozygous for poor metabolism alleles; decreased, combined group of PM and hetEM/IM. Non-adjusted hazard ratios were calculated for the entire patient cohort and subgroups. Subgroups were analyzed with respect to mode of patient sampling and clinical prognostic factors. All comparisons refer to CYP2D6 EM as the reference. The size of the data markers is inversely proportional to the standard error of the hazard ratio.