[Cost-effectiveness analysis comparing methotrexate with PUVA therapy for moderate-severe psoriasis in the sanitary...

To perform a cost-effectiveness analysis, by using a decision tree model, comparing methotrexate with PUVA therapy for moderate to severe chronic plaque psoriasis in the sanitary area of Badajoz (south-western Spain) over a one-year period.

The following variables and data sources were included: efficacy (a 50 % reduction in the PASI) and safety (adverse reactions). Data were retrieved from the dermatologic medical literature, mainly general reviews, systematic reviews and randomized clinical trials. Therapy schedules followed current guidelines from work task teams and consensus documents. Direct costs included unitary costs of medical consults, costs of laboratory tests, pharmacy, phototherapy sessions and costs derived from adverse reactions. Indirect costs included travel expenses and costs of lost productive work time.

Unitary cost of methotrexate therapy would be 952.79 euros per treatment (direct cost: 796.48; indirect cost: 156.31). Unitary cost of PUVA therapy would be 899.70 euros per treatment (direct cost: 383.36; indirect cost: 516.34). Total cost of a one-year treatment with methotrexate would be 255,202.73 euros. Total cost of a one-year treatment with PUVA would be 266,406.88 euros. The average cost-effectiveness ratios per case effectively treated would be 1,519.06 euros for methotrexate therapy, and 1,085.18 euros for PUVA therapy. The incremental cost-effectiveness ratio of PUVA/methotrexate would be 150.65 euros for each additional case effectively treated.

One-year treatment for moderate to severe psoriasis in the sanitary area of Badajoz would be more expensive but also more cost-effective with PUVA than with methotrexate. However, indirect costs (borne by patients), are higher for PUVA therapy, a fact that raises an issue of equity. The results should be interpreted taking into account the methodological limitations of a modelling study.