Our findings demonstrate that RI-HSCT is highly effective and very cost-effective for adolescent and adult thalassemia patients given the consideration of local context on the willingness to pay value. The high success rate of this transplantation is highly regarded as a strong evidence for considering RI-HSCT as a therapeutic alternative for this population. On the overall basis, this study provides key relevant information aiding policy makers to make informed decision making regarding resource allocation.
Clinical effectiveness of RI-HSCT is a key factor driving this intervention to be cost-effective. The high effectiveness rate, demonstrated as low treatment failure and high survival rate, is attributable to 2 key steps of RI-HSCT. First, we used rigorous criteria to select patients for RI-HSCT. We selected only patients with consistent blood transfusion and iron chelation therapy for 1–2 years before transplantation. Second, we had a good pre-transplantation management which was the use of effective medications to suppress bone marrow expansion or alloimmunization from previous multiple blood transfusions such as hydroxyurea, fludarabine and dexamethasone. Previous studies showed that these medications could increase the success rate of transplantation . At present, the moving target of thalassemia treatment is focused on transplantation; a number of cost-effectiveness studies of this treatment have further improved. While the improvement in non-transplant therapy has been a relatively slower process.
The findings of being cost-effective are robust across all sensitivity analyses performed. Our study revealed that the ICERs were sensitive to utility values of BT-ICT patients, discount rate and cost to charge ratio. However, there remains unchanged in terms of direction of overall research findings. The cost-effectiveness acceptability curves suggest that the probability that the RI-HSCT being cost-effectiveness compared to usual care is approximately sixty-four percent using one GDP and ninety-nine percent when using three GDP per capita.
To our knowledge, our study is the first study that determine the cost-effectiveness of RI-HSCT in adolescence and young adult with severe thalassemia patients. A number of clinical studies of RI-HSCT have demonstrated its effectiveness in both pediatric and adult thalassemia population [6–8], but there is a lack of economic evidence of RI-HSCT. There was only one previously published cost-effectiveness study of HSCT . They reported that HSCT to severe thalassemia patients with related or un-related donors was likely to be cost-effective only when provided to patients aged up to 10 years. Our study had demonstrated that RI-HSCT may be a viable option for adolescent and adult severe thalassemia patients who are older than 10 due to the high clinical benefits and cost-effective treatment.
We believe that our findings are highly valid and contextually relevant because we used local data as much as possible in our analysis, as illustrated by the following examples. First, even though there is a lack of survival data for patients treated with blood transfusions in Thailand, we adjusted the mortality rate of BT-ICT patients  by incorporating Thai age-specific mortality rate to reflect Thai population. Secondly, we obtained data on direct medical costs, direct non-medical costs and indirect costs of patients receiving BT-ICT from one of the largest cohort studies of thalassemia patients in Thailand [28, 29]. Thirdly, all cost data were acquired from reliable local sources i.e. national reimbursement rate specified by MOPH and Drugs and Medical Supplies Information Center (DMSIC), Ministry of Public Health. Most importantly, our study was conducted in accordance with pharmacoeconomic guideline in Thailand . The societal perspective undertaken in our analysis was the most widely recommended perspective. Fourth, to our knowledge, this study is the first study in Thailand directly collected quality of life from RI-HSCT patients. Moreover, we derived utility values using Thai preference score for EQ-5D. These make our results more reliable for Thai context.
A number of limitations in our study deserved discussion. First, the survival data and transition probabilities for RI-HSCT patients as well as the direct medical costs of RI-HSCT were obtained from the small number of patients. Because RI-HSCT is considered a new and innovative treatment of thalassemia in Thailand, it was offered only to a few numbers of patients receiving care at a couple of hospitals in Bangkok. Second, the sensitivity analysis indicated that the ICER per QALY gained was most sensitive to changes in the utility of BT-ICT patients which this study obtained from foreign data (UK). This is identified as an area where further studies using local data are needed. Third, the direct medical costs of the interventions were obtained from a single hospital. RI-HSCT is the innovation intervention to cure thalassemia patients and need expert to look after these patients. RI-HSCT patients need to be followed up regularly at the same hospital so all costs could be collected in a single hospital database. However, using a single hospital database could however underestimate the true costs of blood transfusions, as patients might receive these in a number of different hospitals.
These findings are very favorable and could be interpreted by policy makers as paramount evidence to strongly endorse the decision to support the program; however, most of the decision making generally cannot be made based solely on a cost-effectiveness analysis.
Before deciding to support to reimburse RI-HSCT in the any health benefit package, decision makers may be interested in knowing other important issues about the characteristics of the populations that benefit from the transplantation. Then, budget impact analysis should be done along with the implementation suggested, in order to estimate the total budget needed. Moreover, preparing health care system including facilities, resources and treatment knowledge should be transferred to various centers to further expand the chance for the patients to access the treatment. In addition, it is crucial to review the reimbursement system for transplantation in other countries in order to develop appropriate package for the Thai context.