Potential impact of Thai Kidney Transplant program on immunosuppressive utilization: an analysis of the national transplant registry.

Background: The Thai Kidney Transplant (TKT) program was launched in October 2008 to promote transplantation among previously disadvantaged populations, using fixed-rate provider payment. This study investigated if the introduction of this program could alter the natural practice trends of immunosuppressive drug use.

Methods: Data from the Thai Transplantation Registry were analyzed. The change in trend of immunosuppressive use was assessed using the multivariate adaptive regression splines (MARS) technique.

Results: During 1987-2012, 3975 kidney transplantations were done. The average age of patients was 42 years and 62% were male. Chronic glomerulonephritis accounted for one third of those with known causes of end-stage renal disease (ESRD). Eighty-six percent were on hemodialysis before transplantation. Prednisolone was used in 95.87% of all transplant recipients, whereas calcineurin inhibitors (CNIs), mycophenolates (MPAs), azathioprine (AZA), and mammalian target of rapamycin inhibitors (mTORis) were used in 95.67%, 64.22%, 12.25%, and 2.31%, respectively. Overall use after 2008 was decreased for AZA (18.16% to 3.40%) and mTORis (2.86% to 1.5%) but increased for MPAs (50.80% to 84.34%), CNIs (95.43% to 96.04%), and prednisolone (95.60% to 96.29%), as compared with before the program inception. The slopes of use trends of AZA, MPAs, and CNIs did not significantly marginally differ from their natural trends before the program inception (P = .496, .108, and .741, respectively). However, the natural increasing use trend of mTORis significantly changed to a decreasing pattern after the introduction of the TKT program (P = .018).

Conclusion: Fixed-rate provider payment might interfere with the natural practice trends of immunosuppressive drug use.