Effects of treatment adherence on clinical and economic outcomes in patients with psoriasis.

To compare clinical and cost outcomes of psoriasis in non-biological treatment of adherent and non-adherent patients in a developing Balkans country going through socio-economic transition.The study was designed as a retrospective cohort study involving patients with psoriasis adherent and non-adherent to the prescribed treatment regimen. The patients were followed for a period of one year, through four visits with intervals of three months. The adherence to the prescribed regimen was measured at the end of the follow-up period by the medication possession ratio. Clinical outcomes of the treatment were estimated by the Psoriasis Area Severity Index (PASI) at each visit and the treatment costs were collected from patients' files at each visit.The study enrolled 108 patients, 61 (56.5%) were adherent to the prescribed treatment, and 47 (43.5%) were non-adherent. A signiicant decrease of PASI score was noted in the patients adherent to prescribed therapy (p < 0.001). The costs also decreased significantly in the group of adherent patients (p=0.001), and the drop of costs was the highest from the visit 3. The decrease in PASI score and costs were less rapid in non-adherent patients.Better treatment adherence leads to faster clinical improvement and a more rapid decrease in costs of treatment, which diminish overall expenditure of the health system and society, leaving room for treatment of other diseases more efficiently. Therefore, health systems of developing countries should support additional research of causes of treatment non-adherence in patients with psoriasis, in order to minimize this fenomenon more efficiently, and make significant savings.