Pharmacoeconomic evaluation of calcipotriol (Daivonex (R)/Dovonex (R)) andUVB phototherapy in the treatment of psoriasis: A Markov model for the Netherlands

Background: The high prevalence and chronic nature of psoriasis leads to hi gh costs in relation to the treatment and control of the disease. A number of clinical trials have shown that a combination therapy of calcipotriol cr eam (Daivonex(R)/Dovonex(R), Leo Pharmaceutical Products) and ultraviolet B phototherapy (UVB) decreases the total number of UVB exposures required co mpared to UVB treatment alone. From a societal point of view, the addition of calcipotriol to UVB therapy could achieve cost savings due to the fewer UVB treatments needed and the reduced travelling and time off work for pati ents. Fewer UVB exposures may also have other beneficial effects, i.e., sho rtened waiting lists and less risk to patients of developing cancer or phot oaging of the skin. Objective: To compare the cost-effectiveness of treatin g psoriatic patients in the Netherlands with calcipotriol cream used daily combined with twice weekly UVB treatments to emollient used daily combined with UVB given 3 times weekly. Methods: Based on the clinical results from a Canadian trial, a decision-analytical model was constructed to simulate t reatment outcomes and estimate the costs of managing psoriatic patients in the Netherlands over a period of 20 weeks from initiation of therapy. Unit costs and details of standard treatment protocols were collected from Dutch dermatology centres in hospitals and the community for use in the model. O ther therapies, such as topical corticosteroids, tar or dithranol were not investigated in this analysis. Results: The total cost of managing psoriati c patients in the Netherlands over a 20-week period is estimated as EUR 1,1 75.90 for those treated with calcipotriol and UVB and EUR 1,212.14 for pati ents treated with emollient and UVB. Thus, the former treatment, adding cal cipotriol to UVB phototherapy, provides a minor cost saving of EUR 36.24 (3 %) compared to the cost of UVB treatment alone. Sensitivity analyses demons trated that these results are sensitive to changes in the cost of UVB treat ment. Conclusion: Calcipotriol treatment combined with UVB phototherapy is a cost-neutral alternative to UVB phototherapy used with an emollient. The patients achieve treatment success in the same time on both treatments but the former, with calcipotriol, requires less exposure to UVB radiation. The additional drug costs from using calcipotriol are offset by savings from t he fewer UVB sessions required. Essential beneficial effects for patients a re less inconvenience, less risk of developing photoaging of the skin and l ess exposure to potentially carcinogenic radiations. Copyright (C) 2001 S. Karger AG, Basel.