Leucopenia is the most severe adverse event(AE) associated with thiopurine treatment. For the economic analysis we considered that the frequency of occurrence of AE would be 3% (Sanderson-2004), and 1/3 of this AE are related to TPMT decreased activity (Marra (2002)). 2/3 of patients suffering significant leucopenia could be managed as out-patients, requiring two additional visits (132€). The mean hospital stay of a child with ALL with severe myelosuppression is 10 days (480€/day). The healht-costs were taken from the Official Bulletin of Canary-Islands, 2015. The cost-efficacy analysis was done for a hypothetical cohort of 2.000 children with ALL. RESULTS:

For the study population are estimated 60 patients will develop severe myelosuppression. In 20 patients this AE are related to TPMT deficiency with a cost asociated: 7 hospitalized patients (70 days/33.600 €), 13 out-patients (1.716€).

The TPMT genotyping costs for 2000 patients will be 9.280€. So the cost saving will be 26.036€.  CONCLUSIONS:

Our analysis indicates that TPMT genotyping could be considered as an integral part of healthcare prior to the initiation of therapy with thiopurine drugs.