Background and Objectives:
Achieving sustained drug adherence in psoriasis remains challenging despite effective therapies. This exploratory study aims to investigate the care situation and factors associated with drug adherence in patients with moderate-to-severe psoriasis vulgaris (PsO).

Patients and Methods:
A single-center study was conducted at the University Medical Center Regensburg, Germany, comprising a retrospective analysis of 312 patient records of individuals treated between 01/2023 and 06/2023 and a prospective questionnaire-based cross-sectional survey of 62 patients treated between 10/2023 and 03/2024. Sociodemographic, clinical, and treatment-related variables and quality of life (QoL) were analyzed descriptively and explored using inferential statistics.

Results:
Most patients resided outside the urban care center (82.1% retrospective, 81.0% prospective). Approximately three quarters were adherent (75.0% and 72.4%, respectively). Non-adherence was associated with occupational status, medication class, adverse events, and nicotine use. Patient-reported reasons included administrative barriers (43.8%), financial burden, and adverse events (18.8% each). Non-adherent patients tended to report higher disease burden and lower QoL.

Conclusions:
Drug adherence in moderate-to-severe PsO is associated with socioeconomic and therapy-related factors. Targeted patient-centered strategies may help improve long-term adherence, particularly in vulnerable patient groups, optimize overall outcomes, and reduce financial burden on the healthcare system.