research guide

Interpretation of the estimates of the prevalence of psoriasis

How prevalence estimates have been calculated?

An extensive search of all available evidence was conducted and all the published articles on the prevalence of psoriasis were identified. All the information reported was assessed and used them to inform a statistical model. The statistical model generated a pooled estimate of the prevalence of psoriasis for each individual country where data were identified. Each prevalence measure is presented together with a range (uncertainty interval) which represents the uncertainty surrounding the estimate. Therefore, these values are not to be interpreted as exact measures, but only as measures which can vary within a certain range.

Countries with missing data

To be noted, many countries of the world do not provide information on the prevalence of psoriasis. For these countries, without high quality original data sources, estimates were generated by extrapolation, making using of the psoriasis prevalence estimate of the region the country was nested in, grouped according to the United Nations classification. Therefore, extrapolated estimated are less reliable, than for countries with original data sources and should be interpreted with caution. Please note, a publication will be available soon where all the countries with extrapolated estimates will be listed in a Table.
Adults

Refers to all adult population.
Age-specific rate

A rate for a specified age group (adults or children), in which the numerator and denominator refers to the same age group.
Age-standardisation

A statistical technique that facilitates comparison of prevalence rates between populations or overtime, adjusting for differences in the age structure of the general population in the countries or regions being compared.
Children

Refers to all children and adolescents individuals.
Country

Prevalence data are presented for 196 countries of the world *. Countries are nested into regions which are nested into super-regions.
Diagnosis

The process of identifying a disease by its signs and symptoms. The diagnosis of psoriasis can be made either by a general practitioner/ physician or by a dermatologist.
Incidence

The number of new cases arising in a given period in a specified population. This information can be expressed as an absolute number of cases per year or as a rate per 100,000 persons per year.
Meta-analysis

A statistical analysis that combines the results of multiple studies addressing the same question with the aim of deriving a pooled estimate closest to the unknown common truth.
Overall population

Refers to all individuals of any age, therefore children and adults combined.
Prevalence

The existing number of persons in a defined population who have been diagnosed with psoriasis. It is usually expressed as a proportion and can assume different definitions according to how it is measured. Therefore, it can be classified into: point, period and lifetime prevalence. Point prevalence: when the number of cases refers to a specific time point (e.g. a year). Period prevalence: when the number of cases refers to a time-window (e.g. between 2000 and 2010). Lifetime prevalence: when it refers to the entire previous life of an individual (e.g. “Have you ever been diagnosed with psoriasis?”).
Region

Prevalence data are presented for 21 regions of the world (which contain 196 countries) *. Regions are nested into super-regions.
Super-Region

Prevalence data are presented for 7 super-regions of the world (which contain 21 regions in which are nested 196 countries) *.
Uncertainty Intervals/Credible Intervals

Uncertainty intervals have been produced by the statistical models to quantify the uncertainty around prevalence estimates. These intervals thus reflect the uncertainty levels around the psoriasis prevalence estimates.
*according to the definition of the United Nation - https://population.un.org

select region: Global
- Global
- Andean Latin America
- Australasia
- Caribbean
- Central Asia
- Central Europe
- Central Latin America
- Central sub-Saharan Africa
- East Asia
- Eastern Europe
- Eastern sub-Saharan Africa
- High-income Asia Pacific
- High-income North America
- High-income Southern Latin America
- North Africa and Middle East
- Oceania
- South Asia
- Southeast Asia
- Southern sub-Saharan Africa
- Tropical Latin America
- Western Europe
- Western sub-Saharan Africa
select country:
- Afghanistan
- Albania
- Algeria
- American Samoa
- Andorra
- Angola
- Antigua and Barbuda
- Argentina
- Armenia
- Australia
- Austria
- Azerbaijan
- Bahrain
- Bangladesh
- Barbados
- Belarus
- Belgium
- Belize
- Benin
- Bermuda
- Bhutan
- Bolivia
- Bosnia and Herzegovina
- Botswana
- Brazil
- Brunei
- Bulgaria
- Burkina Faso
- Burundi
- Cambodia
- Cameroon
- Canada
- Cape Verde
- Central African Republic
- Chad
- Chile
- China
- Colombia
- Comoros
- Congo, Dem. Rep.
- Congo, Rep.
- Costa Rica
- Côte d'Ivoire
- Croatia
- Cuba
- Cyprus
- Czech Republic
- Denmark
- Djibouti
- Dominica
- Dominican Republic
- Ecuador
- Egypt
- El Salvador
- Equatorial Guinea
- Eritrea
- Estonia
- Ethiopia
- Fiji
- Finland
- France
- FYR Macedonia
- Gabon
- Gambia, The
- Georgia
- Germany
- Ghana
- Greece
- Greenland
- Grenada
- Guam
- Guatemala
- Guinea
- Guinea-Bissau
- Guyana
- Haiti
- Honduras
- Hungary
- Iceland
- India
- Indonesia
- Iran
- Iraq
- Ireland
- Israel
- Italy
- Jamaica
- Japan
- Jordan
- Kazakhstan
- Kenya
- Kiribati
- Kuwait
- Kyrgyzstan
- Laos
- Latvia
- Lebanon
- Lesotho
- Liberia
- Lithuania
- Luxembourg
- Lybia
- Madagascar
- Malawi
- Malaysia
- Maldives
- Mali
- Malta
- Marshall Islands
- Mauritania
- Mauritius
- Mexico
- Micronesia, Fed. Sts.
- Moldova
- Mongolia
- Montenegro
- Morocco
- Mozambique
- Myanmar
- Namibia
- Nepal
- Netherlands
- New Zealand
- Nicaragua
- Niger
- Nigeria
- North Korea
- Northern Mariana Islands
- Norway
- Oman
- Pakistan
- Palestine
- Panama
- Papua New Guinea
- Paraguay
- Peru
- Philippines
- Poland
- Portugal
- Puerto Rico
- Qatar
- Romania
- Russian Federation
- Rwanda
- Samoa
- São Tomé and Príncipe
- Saudi Arabia
- Senegal
- Serbia
- Seychelles
- Sierra Leone
- Singapore
- Slovakia
- Slovenia
- Solomon Islands
- Somalia
- South Africa
- South Korea
- South Sudan
- Spain
- Sri Lanka
- St. Lucia
- St. Vincent and the Grenadines
- Sudan
- Suriname
- Swaziland
- Sweden
- Switzerland
- Syria
- Taiwan
- Tajikistan
- Tanzania
- Thailand
- The Bahamas
- Timor-Leste
- Togo
- Tonga
- Trinidad and Tobago
- Tunisia
- Turkey
- Turkmenistan
- Uganda
- Ukraine
- United Arab Emirates
- United Kingdom
- United States
- Uruguay
- Uzbekistan
- Vanuatu
- Venezuela, RB
- Vietnam
- Virgin Islands (U.S.)
- Yemen, Rep.
- Zambia
- Zimbabwe
search country
sort country: a-z
- A - Z
- Z - A

Prevalence
data

The prevalence (number of cases) of psoriasis appears to vary depending on genetic background and geographic location. Learn about the prevalence of psoriasis here.

research guide

Interpretation of the estimates of the prevalence of psoriasis

How prevalence estimates have been calculated?

Countries with missing data

Adults

Age-specific rate

Age-standardisation

Children

Country

Diagnosis

Incidence

Meta-analysis

Overall population

Prevalence

Region

Super-Region

Uncertainty Intervals/Credible Intervals

select region: Global

select country:

search country

sort country: a-z

Prevalence data

Prevalence
data