Association Of Health Care Expenditure With Results Of Allogeneic HSCT For Adults With ALL: An Analysis From Acute Leukemia Working Party Of The EBMT

Results of allogeneic hematopoietic stem cell transplantation (aloHSCT) depend on many patient-, donor- and procedure-related factors. In recent years, in a setting of AML we demonstrated that also socio-economic status of a country and center experience may influence outcome. The goal of the current analysis, focused on patients with acute lymphoblastic leukemia (ALL), was to evaluate specific effects on non-relapse mortality (NRM) related to health care expenditure (HCE) of a country as well as distribution of transplant centers in addition to previously studied human development index (HDI) and center activity.

Results of myeloablative alloHSCT from HLA-identical siblings performed between 2004-2008 for adults with ALL in CR1 were analyzed. Among 983 individuals treated in 27 European countries the median age was 35 (18-55) years and the interval from diagnosis to alloHSCT – 158 (42-831) days. TBI was used for conditioning in 820 (83%) cases and peripheral blood was a source of stem cells in 656 (67%) cases. The following factors were studied for their impact on outcome: current HCE, HCE as % of gross domestic product, public HCE, private HCE, no. of teams per country area and population, HDI and center activity (no. of alloHSCT for ALL in a study period). All variables were categorized by medians. The median follow-up was 34 months.

In a univariate analysis the probability of day 100 NRM was increased for countries with lower current HCE (p=0.06), lower HDI (p=0.02) and for centers with lower experience (p=0.04). Also overall NRM was affected by current HCE (p=0.09), HDI (p=0.03) and center activity (p=0.07). In a multivariate model adjusted for recipient age, interval from diagnosis to HSCT, source of stem cells, type of conditioning, and donor/recipient gender, the variables of interest were included separately due to strong internal correlations. The best predictive model for day 100 NRM included HDI < median (HR = 2.38, 95%CI = 1.3-4.35, p=0.005). The overall NRM was most strongly predicted by current HCE < median (HR = 2.56, 95%CI = 1.41-4.76, p=0.002). In a univariate analysis lower values of HDI and current HCE were also associated with decreased probability of the overall survival (p=0.004 and p=0.006, respectively).

Both macroeconomic factors and the socio-economic status of a country influence strongly non-relapse mortality and overall survival after alloHSCT for adults with ALL. Our findings should be considered in interpretation of clinical studies in the field of alloHSCT.

No relevant conflicts of interest to declare.