Pharmacoeconomic analysis of thiopurine methyltransferase polymorphism screening by polymerase chain reaction for treatment with azathioprine in Korea.
OBJECTIVE
To evaluate the value of genotype-based dosing by polymerase chain reaction (PCR)-based polymorphism screening in terms of cost-effectiveness for treatment with azathioprine in Korea.


METHODS
Decision analysis was employed to compare a genotype-based dosing strategy with the conventional weight-based dosing strategy using a hypothetical cohort composed of rheumatoid arthritis and systemic lupus erythematosus patients. The time horizon was set up as 1 yr. Direct medical costs were used. Data used were obtained from previous reports, except for PCR and admission costs, which were from real cases. Cost-effectiveness analysis was conducted from a societal perspective. Outcomes were measured as a total expected cost and an incremental cost-effective ratio.


RESULTS
In the base case model, total expected cost and the probability of not dropping out owing to serious adverse events of the conventional weight-based dosing and the genotype-based dosing strategy were 1339 x 10(3) Korean won (1,117 US dollars) and 1109 x 10(3) Korean won (926 US dollars), and 97.06 and 99.90%, respectively.


CONCLUSIONS
Our model suggests that a genotype-based dosing strategy through PCR-based thiopurine methyltransferase (TPMT) polymorphism screening is less costly and more effective than the conventional weight-based dosing strategy in Korea, as it was associated with a marked reduction in the number of serious adverse events.
Oh
K-T
KT
Department of Internal Medicine, Division of Rheumatology, Hanyang University College of Medicine and the Hospital for Rheumatic Diseases, Hanyang University Medical Center, Seoul, Republic of Korea.
Anis
A H
AH
Bae
S-C
SC
D018501:Antirheumatic Agents / Q000008:administration & dosage* / Q000009:adverse effects; D001172:Arthritis, Rheumatoid / Q000188:drug therapy / Q000191:economics / Q000235:genetics; D001379:Azathioprine / Q000008:administration & dosage* / Q000009:adverse effects; D003362:Cost-Benefit Analysis; D003663:Decision Trees; D004180:Direct Service Costs; D004334:Drug Administration Schedule; D005820:Genetic Testing / Q000191:economics* / Q000379:methods; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000009:adverse effects; D007723:Korea; D008180:Lupus Erythematosus, Systemic / Q000188:drug therapy / Q000191:economics / Q000235:genetics; D008780:Methyltransferases / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic
D018501:Antirheumatic Agents; D007166:Immunosuppressive Agents; D008780:Methyltransferases; C022745:thiopurine methyltransferase; D001379:Azathioprine