How I Treat How I assess comorbidities before hematopoietic cell transplantation

Organ dysfunctions (comorbidities) were found to be associated with the outcome of treatment of a given primary disease and, in particular, cancer. In 2005, a hematopoietic cell transplantationcomorbidity index (HCT-CI) was introduced as a measure of organ dysfunctions that was suited for recipients of HCT. The HCT-CI was developed from the historical Charlson comorbidity index after introducing 3 conceptual changes: the use of laboratory and organ function tests to redefine pulmonary, hepatic, cardiac, and renal comorbidities; the inclusion of all comorbidities encountered in a cohort of HCT recipients at a single institution; and the estimation of new adjusted hazard ratios for the associations between comorbidities and nonrelapse mortality after HCT. These adjusted hazard ratios were then converted into weights that could be summated into a total score. In validation cohorts of recipients of allogeneic HCT from 2 different institutions, the HCT-CI was demonstrated to have higher discriminative power than the Charlson comorbidity index, both for non-relapse mortality and overall survival. Many investigators reported on the valid association between HCT-CI scores and mortality in their respective single-institutions, whereas a few others disagreed. A discussion of the possible reasons for the lack of complete agreement by investigators on the validity of the HCT-CI is outside the scope of this article. Instead, the focus of this article is a single concern that is related to the degree of consistency in assigning comorbidity scores among evaluators. For example, a recent study reported a noticeably higher prevalence of comorbidities compared with other reports. As investigators continue to explore the validity of the HCT-CI and to use it in decision-making and prognostication studies, an urgent need has emerged to standardize the methods and guidelines for comorbidity evaluation. A valid and reliable system for comorbidity evaluation would not only ensure the calculation of an accurate total comorbidity score but also allow the accurate estimation of the prevalence of individual comorbidities, which would be of prime importance in future research addressing roles of comorbidities in post-HCT complications. Here, a brief training program is proposed comprising consistent methods for data acquisition from medical records and detailed guidelines for comorbidity assessment that were summarized in a Web-based application and a calculator. Validation of the ability of the proposed training program to improve the interrater reliability (IRR) of the HCT-CI is also described.