P31 Global epidemiology of psoriasis: Global Psoriasis Atlas 2024 update

Abstract The WHO has highlighted the necessity of gaining a deeper understanding of the global burden of psoriasis. In response to this need, the Global Psoriasis Atlas was established to conduct comprehensive research into the global prevalence and incidence of psoriasis. We aimed to systematically review and present up-to-date data on the incidence of psoriasis, as well as to quantify its prevalence at global, regional, and country-specific levels. Literature searches were updated from 2019 to January 2024, resulting in 48 new studies. Among these, 13 studies reported incidence data, 7 reported only incidence, 6 reported both prevalence and incidence, and the remaining 35 studies reported only prevalence. In total, our updated prevalence analysis included 170 population-based epidemiological studies. A Bayesian hierarchical linear mixed model was employed to estimate the global, regional, and country-specific prevalence of psoriasis. Countries were mapped according to the global burden of disease (GBD) classification, considering geography and income. The data were fitted to a statistical model using Bayesian inference, sampling from a posterior distribution through a Hamiltonian Markov chain Monte Carlo method implemented in the RStanArm package in R (version 4.4.0). The updated review incorporated data from eight new countries and expanded to cover two additional GBD global regions. We observed a global increase in the prevalence of psoriasis, with some variations attributed to the significant expansion with the update of certain very sparse datasets. The crude lifetime prevalence for adults in high-income countries increased from 1.12% [95% confidence interval (CI): 0.39, 2.79] to 1.40% (95% CI: 0.52, 3.25). In the Latin America and Caribbean super-region, prevalence rates appear to have slightly decreased, but this finding is based on a very low evidence base, with no studies on psoriasis prevalence included from Caribbean countries. Most of the newly added studies were from high-income countries, with 70% originating from Western Europe, North America, and high-income Asian countries. The incidence of psoriasis varied from 23.14 per 100 000 person years in Taiwan to 321.0 per 100 000 person years in Italy. The incidence of psoriasis was higher in adults than in children. Seventy-six per cent of countries worldwide lack data on the epidemiology of psoriasis. The prevalence of psoriasis is higher in adults compared with children. Additionally, the distribution of psoriasis varies geographically, with higher frequency observed in high-income countries and regions with older populations. These estimates can assist countries and the international community in making informed public health decisions regarding the appropriate management of psoriasis and in monitoring changes over time.