A pooled analysis of randomized, controlled, phase 3 trials investigating the efficacy and safety of a novel, fixed dose calcipotriene and betamethasone dipropionate cream for the topical treatment of plaque psoriasis

Abstract Objective To systematically review and provide information on the incidence of psoriasis and quantify global, regional, and country specific estimates of its prevalence. Design Systematic review and meta-analysis. Data sources Medline, Embase, Web of Science, SciELO, Korean Journal Databases, Russian Science Citation Index, WPRIM, SaudiMedLit, Informit, IndMed, and HERDIN were searched systematically from their inception dates to October 2019. Methods Studies were included if they reported on the incidence or prevalence of psoriasis in the general population. Incidence data were summarised descriptively, whereas bayesian hierarchical models were fitted to estimate the global, regional, and country specific prevalence of psoriasis. Results 41 164 records were identified and 168 studies met the inclusion criteria. In adults, the incidence of psoriasis varied from 30.3 per 100 000 person years (95% confidence interval 26.6 to 34.1) in Taiwan to 321.0 per 100 000 person years in Italy. The prevalence of psoriasis varied from 0.14% (95% uncertainty interval 0.05% to 0.40%) in east Asia to 1.99% (0.64% to 6.60%) in Australasia. The prevalence of psoriasis was also high in western Europe (1.92%, 1.07% to 3.46%), central Europe (1.83%, 0.62% to 5.32%), North America (1.50%, 0.63% to 3.60%), and high income southern Latin America (1.10%, 0.36% to 2.96%). Conclusions Eighty one per cent of the countries of the world lack information on the epidemiology of psoriasis. The disease occurs more frequently in adults than in children. Psoriasis is unequally distributed across geographical regions; it is more frequent in high income countries and in regions with older populations. The estimates provided can help guide countries and the international community when making public health decisions on the appropriate management of psoriasis and assessing its natural history over time. Systematic review registration PROSPERO CRD42019160817.

Psoriasis is a chronic inflammatory disorder associated with significant morbidity and mortality. Up-to-date prevalence data on psoriasis provide the foundation for informing population research, education, and health policy. We sought to determine the prevalence of psoriasis among US adults. We performed a cross-sectional study using National Health and Nutrition Examination Survey 2009 through 2010 data to determine psoriasis prevalence rates. From 6218 participants older than 20 years of age, 6216 respondents provided complete information regarding a psoriasis diagnosis. The prevalence of psoriasis among US adults ages 20 years and older is 3.2% (95% confidence interval [CI] 2.6%-3.7%). A total of 7.2 million US adults had psoriasis in 2010; an estimated 7.4 million US adults were affected in 2013. When stratifying the sample by race among those between ages 20 and 59 years, the psoriasis prevalence was highest in Caucasians at 3.6% (95% CI 2.7%-4.4%), followed by African Americans (1.9%; 95% CI 1.0%-2.8%), Hispanics (1.6%; 95% CI 0.5%-2.8%), and others (1.4%; 95% CI 0.3%-2.6%). The prevalence of psoriasis among US adults has not changed significantly since 2003 to 2004 (P > .05). Dermatologist evaluation and skin photographs were unavailable for the 2009 through 2010 surveys. In the United States, psoriasis remains a common, immune-mediated disease, affecting 7.4 million adults. Its prevalence has remained stable since the mid-2000s. Copyright © 2013 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.