Societal value of stem cell therapy in stroke--a modeling study.

Background: Stroke is one of the major causes of disability in the adult population and represents a heavy social and economic burden. Currently available therapeutic tools to support the recovery of impaired brain functions are quite limited. Animal studies have demonstrated that neuronal replacement and partial reconstruction of neural circuitry or modulation of the recovery process is possible with cell transplantation in the damaged adult brain. Stem cell therapy (SCT) may promote functional recovery also in stroke patients, thereby improving quality of life and reducing costs. Our aim was to estimate the potential societal value of SCT in stroke patients.

Methods: We created a decision-analytic model in Microsoft Excel 2010 to assess life-long costs and quality-adjusted life years (QALYs) of SCT versus standard care for stroke patients from a societal perspective. The model structure consisted of 7 health states in accordance with the modified Rankin Scale (mRS). We modeled for age (55, 65, and 75 years), functional status at discharge (mRS 2, 3, and 4), effectiveness of SCT (50 and 25% increase in the probability to improve 1 mRS grade), mode of stem cell administration, risk of recurrent stroke, complications of intervention, and use of immunosuppressive drugs. The difference between an assumed societal willingness to pay for a QALY gain in Sweden (110,400 USD) and the cost per QALY gain resulting from the model was interpreted as the value of SCT.

Results: Increased survival (1.06 life years) and improved functional status gave rise to an estimated gain of 1.34 QALY in a cohort of patients aged 55 with mRS 2 at hospital discharge. Although the SCT intervention increased costs by 64,014 USD (excluding cost of stem cells), the costs of intervention were offset mainly by decreased productivity losses. In total, the intervention saved 19,055 USD, i.e., at a price of 19,055 USD for stem cells, the SCT would be cost neutral. The societal value of SCT was 166,500 USD.

Conclusions: The application of the health-economic model to Sweden shows that in younger stroke patients with moderate disability, the societal value of SCT given a zero price of stem cells is 166,500 USD. Although the transplantation itself is more costly, SCT offers potential for cost offset and cost savings in a long-term perspective by reducing the disability after stroke. The therapy appeared cost effective under a wide range of assumptions. Hence, further research and development in stem cells suitable for stroke therapy could potentially produce great value to society.