Barriers to the prescription of systemic therapies for moderate-to-severe psoriasis--a multinational cross-sectional study.

Despite the availability of a plethora of approved systemic treatments, high proportions of patients with moderate-to-severe psoriasis do not receive systemic treatment. This study aims at identifying barriers that hinder dermatologists from prescribing systemic treatments for psoriasis. A cross-sectional online survey in six countries (Canada, Germany, Spain, France, Italy, UK) was performed among 300 dermatologists, assessing the relevance of 15 potential barriers towards prescribing acitretin, cyclosporine, methotrexate, adalimumab, etanercept, infliximab and ustekinumab. Multivariate regression analyses were used to explore provider characteristics related to these barriers. Treatment barriers are perceived differently in the countries investigated, with Spanish, Italian and Canadian dermatologists being particularly concerned about the safety of methotrexate and Canadian dermatologists about the safety of cyclosporine. In general, safety concerns were the most important barrier to the use of cyclosporine, (18 % of participants' moderate/9 % strong or very strong barrier). Costs were being perceived as a strong or very strong barrier to the use of the different biologics by 19-24 % of the participants. Overall, country and work place were the most important determinants of treatment barriers. Sex, age, training, position and experience were minor determinants of treatment barriers. Medical reasons such as safety concerns or an inappropriate risk-benefit profile are particularly relevant barriers to the prescription of conventional treatments; whereas for biological treatments, economic reasons such as costs are more prevalent. Country specific analysis showed national differences in the perception of safety. The treatment barriers identified in this exploratory study should be confirmed in further health services research.