Comorbidity-age index: a clinical measure of biologic age before allogeneic hematopoietic cell transplantation.

PurposeAge has long been used as a major factor for assessing suitability for allogeneic hematopoietic cell transplantation (HCT). The HCT-comorbidity index (HCT-CI) was developed as a measure of health status to predict mortality risk after HCT. Whether age, comorbidities, or both should guide decision making for HCT is unknown.Patients and methodsData from 3,033 consecutive recipients of HLA-matched grafts from five institutions contributed to this analysis. Patients were randomly divided into a training set to develop weights for age intervals and a validation set to assess the performance of prognostic models.ResultsIn the training set, patients age 20 to 39 years, 40 to 49 years, 50 to 59 years, and ≥ 60 years had hazard ratios for nonrelapse mortality (NRM) of 1.21 (P = .29), 1.48 (P = .04), 1.75 (P = .004), and 1.84 (P = .005), respectively, compared with those age younger than 20 years. Consequently, age ≥ 40 years was assigned a weight of 1 to be added to the HCT-CI to constitute a composite comorbidity/age index. In the validation set, the composite comorbidity/age score had statistically significantly higher c-statistic estimates for prediction of NRM (0.664 v 0.556; P ConclusionAge is a poor prognostic factor. The proposed composite measure allows integration of both comorbidities and age into clinical decision making and comparative-effectiveness research of HCT.