RESUMEN
BACKGROUND: Treatment persistence is becoming a useful measure to evaluate long-term effectiveness and safety of biological therapies in real-world settings. OBJECTIVE: The main objective of this study was to explore the scientific opinion of a panel of dermatologists and hospital pharmacists to reach a consensus about the impact, causes, and best strategies and interventions that might be associated with improved drug persistence in patients with psoriasis in Spain. METHODS: This research was conducted using a modified Delphi method organized in two rounds and involving a panel of 90 dermatologists and 34 hospital pharmacists. A questionnaire of 70 items was developed. The items proposed to reach a consensus included topics such as definitions and measures in the treatment of psoriasis, analysis of treatment persistence, factors that may influence treatment persistence, impact of treatment persistence and economic cost of treatment. RESULTS: Dermatologists reached a consensus on 77.1% of the items proposed, and hospital pharmacists reached a consensus on 71.4%. Both groups agreed that it is important to use standardized measures in the evaluation of treatment maintenance over time. Dermatologists agreed that treatment survival, persistence and retention are synonymous, but hospital pharmacists considered only treatment persistence as a valid term. In addition, panelists agreed that drug persistence is an indicator of success in the treatment of psoriasis that may be influenced by a drug's effectiveness and safety profile, as well as by patient satisfaction. They agreed that the different causes of treatment discontinuation should be considered in Kaplan-Meier analysis of treatment persistence. Moreover, treatment persistence was agreed to decrease the cost of therapy. CONCLUSION: This Delphi consensus highlights the different perspectives of dermatologists and hospital pharmacists regarding the interpretation of treatment persistence, and the challenge of harmonizing the results obtained.