Biological drugs have prompted a revolution in the treatment of patients with psoriasis because of their favourable efficacy/risk profile. The aims of our study are to determine whether there is any difference in the pattern of use of biological treatments for older (65+ years) and younger patients diagnosed with plaque psoriasis by the Dermatology Service of the Hospital Universitario de Asturias (HUCA), to understand the survival of these drugs, and to identify the factors that predict the discontinuation of treatments. We report a retrospective observational hospital-based study of 300 patients registered at HUCA's Dermatology Service who were receiving one of the following biological treatments for psoriasis on 30 November 2020: adalimumab, ustekinumab, secukinumab, or ixekizumab. The age groups were compared using Student's t-test for quantitative variables and the chi-squared test for qualitative variables. We used the Kaplan-Meier estimator to estimate the survival function and the log-rank test to measure differences. No statistically significant differences in the frequency of use were noted between the younger and older groups, for any of the drugs studied. Survival on a drug regime, globally and individually, was similar in the two age groups. Factors predicting lower overall survival were being female, obesity, and having undergone previous biological treatment. The first three factors were influential in the under-65-year-old group, while arthritis was a significant factor for the older group.
Keywords: biological treatment; drug survival; elderly; psoriasis.