Health economic analyses of psoriasis management: a systematic literature search

In the course of the chronic skin disease psoriasis, where a variety of treatment interventions is available, a strong growth of health economic studies comparing treatment costs and benefits can be noticed. The objective was to identify health economic evaluations of psoriasis treatments that have been published to date. Of particular interest were the mostly used analysis and outcome parameters, the compared treatments, and the question, if available health economic studies may be used to perform a meta-analysis of qualitative findings. A systematic literature search using PubMed Medline, Ovid Medline, and Cochrane Library was performed for articles, published and available until mid of January 2016. Among the key words were the terms "psoriasis" and "cost-effectiveness". The search resulted in 318 articles without duplicates. Thereof 60 health economic analyses in psoriasis management were identified. Most of these are cost-effectiveness evaluations (45). The clinical parameter PASI (Psoriasis Area Severity Index) is the most often used cost-effectiveness outcome (33) followed by the Dermatology Life Quality Index (DLQI) (6). In case of cost-utility analyses, QALYs (quality-adjusted life-years) were mostly generated with the help of EuroQol five dimensions questionnaire (EQ-5D) (12), which was partly based on PASI and DLQI values. The majority of health economic studies is focusing on the direct medical and non-medical costs without consideration of productivity losses. Almost 70 % of 60 publications were conducted in Europe. Overall, most considered systemic treatments were the biological agents etanercept (36), adalimumab (27), and infliximab (26) followed by ustekinumab (17) and phototherapy (incl. UV-B, PUVA/psoralen combined with UV-A) (14). Comparisons including only topical treatments mostly focused on vitamin D treatment (14), corticosteroids (13), and coal tar products (6) followed by dithranol (5) and tazarotene (4). Given the setting, compared treatments, and study conditions, different results can be found for medical decision-making. Thereby, it can be noted that there are no standards on methods and outcomes measures available. This leads to a very limited comparability of health economic studies and presents no comfortable basis to examine a meta-analysis of health economic results. The presented systematic review shows the need for nationwide data and interpretation.