In 2024, the population of the United Kingdom reached 69.3 million, compared with 68.5 million in 2023. The UK population has more than doubled since 1871 when just under 31.5 million lived in the UK and has grown by around 10.4 million since the start of the twenty-first century. For most of the twentieth century, the UK population steadily increased, with two noticeable drops in population occurring during World War One (1914-1918) and in World War Two (1939-1945). Demographic trends in postwar Britain After World War Two, Britain and many other countries in the Western world experienced a 'baby boom,' with a postwar peak of 1.02 million live births in 1947. Although the number of births fell between 1948 and 1955, they increased again between the mid-1950s and mid-1960s, with more than one million people born in 1964. Since 1964, however, the UK birth rate has fallen from 18.8 births per 1,000 people to a low of just 10.2 in 2020. As a result, the UK population has gotten significantly older, with the country's median age increasing from 37.9 years in 2001 to 40.7 years in 2022. What are the most populated areas of the UK? The vast majority of people in the UK live in England, which had a population of 58.6 million people in 2024. By comparison, Scotland, Wales, and Northern Ireland had populations of 5.5 million, 3.2 million, and 1.9 million, respectively. Within England, South East England had the largest population, at over 9.6 million, followed by the UK's vast capital city of London, at almost 9.1 million. London is far larger than any other UK city in terms of urban agglomeration, with just four other cities; Manchester, Birmingham, Leeds, and Glasgow, boasting populations that exceed one million people.
The population of England was estimated to have reached almost 58.6 million in 2024, compared with 54.4 million ten years earlier in 2013. Compared with 1971, the population of England has grown by over 12 million.
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National and subnational mid-year population estimates for the UK and its constituent countries by administrative area, age and sex (including components of population change, median age and population density).
The statistic depicts the median age of the population in the United Kingdom from 1950 to 2100*. The median age of a population is an index that divides the population into two equal groups: half of the population is older than the median age and the other half younger. In 2020, the median age of United Kingdom's population was 39.2 years. Population of the United Kingdom The United Kingdom (UK) includes Great Britain (England, Scotland and Wales) and Northern Ireland, and is a state located off the coast of continental Europe. The United Kingdom is a constitutional monarchy, which means the Queen acts as representative head of state, while laws and constitutional issues are discussed and passed by a parliament. The total UK population figures have been steadily increasing, albeit only slightly, over the last decade; in 2011, the population growth rate was lower than in the previous year for the first time in eight years. Like many other countries, the UK and its economy were severely affected by the economic crisis in 2009. Since then, the unemployment rate has doubled and is only recovering slowly. UK inhabitants tend to move to the cities to find work and better living conditions; urbanization in the United Kingdom has been on the rise. At the same time, population density in the United Kingdom has been increasing due to several factors, for example, the rising number of inhabitants and their life expectancy at birth, an increasing fertility rate, and a very low number of emigrants. In fact, the United Kingdom is now among the 20 countries with the highest life expectancy at birth worldwide. As can be seen above, the median age of UK residents has also been increasing significantly since the seventies; another indicator for a well-working economy and society.
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Context
The dataset tabulates the data for the England, AR population pyramid, which represents the England population distribution across age and gender, using estimates from the U.S. Census Bureau American Community Survey (ACS) 2019-2023 5-Year Estimates. It lists the male and female population for each age group, along with the total population for those age groups. Higher numbers at the bottom of the table suggest population growth, whereas higher numbers at the top indicate declining birth rates. Furthermore, the dataset can be utilized to understand the youth dependency ratio, old-age dependency ratio, total dependency ratio, and potential support ratio.
Key observations
When available, the data consists of estimates from the U.S. Census Bureau American Community Survey (ACS) 2019-2023 5-Year Estimates.
Age groups:
Variables / Data Columns
Good to know
Margin of Error
Data in the dataset are based on the estimates and are subject to sampling variability and thus a margin of error. Neilsberg Research recommends using caution when presening these estimates in your research.
Custom data
If you do need custom data for any of your research project, report or presentation, you can contact our research staff at research@neilsberg.com for a feasibility of a custom tabulation on a fee-for-service basis.
Neilsberg Research Team curates, analyze and publishes demographics and economic data from a variety of public and proprietary sources, each of which often includes multiple surveys and programs. The large majority of Neilsberg Research aggregated datasets and insights is made available for free download at https://www.neilsberg.com/research/.
This dataset is a part of the main dataset for England Population by Age. You can refer the same here
In 2024, there were estimated to be 976,481 people who were aged 33 in the United Kingdom, the most of any age in this year. The two largest age groups during this year were 30-34, and 35-39, at 4.8 million and 4.78 million people respectively. There is also a noticeable spike of 673,831 people who were aged 77, which is due to the high number of births that followed the end of the Second World War. Over one million born in 1964 In post-war Britain, there have only been two years when the number of live births was over one million, in 1947 and in 1964. The number of births recorded in the years between these two years was consistently high as well, with 1955 having the fewest births in this period at 789,000. This meant that until relatively recently, Baby Boomers were the largest generational cohort in the UK. As of 2024, there were approximately 13.4 million Baby Boomers, compared with 14 million in Generation X, 15 million Millennials, and 13.6 million members of Gen Z. The youngest generation in the UK, Generation Alpha, numbered approximately 9.2 million in the same year. Median age to hit 44.5 years by 2050 The population of the United Kingdom is aging at a substantial rate, with the median age of the population expected to reach 44.5 years by 2050. By comparison, in 1950 the average age in the United Kingdom stood at 34.9 years. This phenomenon is not unique to the United Kingdom, with median age of people worldwide increasing from 23.6 years in 1950 to a forecasted 41.9 years by 2100. As of 2024, the region with the oldest median age in the UK was South West England, at 43.7 years, compared with 35.7 in London, the region with the youngest median age.
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United Kingdom UK: Age Dependency Ratio: % of Working-Age Population data was reported at 56.810 % in 2017. This records an increase from the previous number of 56.175 % for 2016. United Kingdom UK: Age Dependency Ratio: % of Working-Age Population data is updated yearly, averaging 54.363 % from Dec 1960 (Median) to 2017, with 58 observations. The data reached an all-time high of 60.489 % in 1973 and a record low of 51.330 % in 2007. United Kingdom UK: Age Dependency Ratio: % of Working-Age Population data remains active status in CEIC and is reported by World Bank. The data is categorized under Global Database’s United Kingdom – Table UK.World Bank.WDI: Population and Urbanization Statistics. Age dependency ratio is the ratio of dependents--people younger than 15 or older than 64--to the working-age population--those ages 15-64. Data are shown as the proportion of dependents per 100 working-age population.; ; World Bank staff estimates based on age distributions of United Nations Population Division's World Population Prospects: 2017 Revision.; Weighted average; Relevance to gender indicator: this indicator implies the dependency burden that the working-age population bears in relation to children and the elderly. Many times single or widowed women who are the sole caregiver of a household have a high dependency ratio.
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Context
The dataset tabulates the population of England by gender across 18 age groups. It lists the male and female population in each age group along with the gender ratio for England. The dataset can be utilized to understand the population distribution of England by gender and age. For example, using this dataset, we can identify the largest age group for both Men and Women in England. Additionally, it can be used to see how the gender ratio changes from birth to senior most age group and male to female ratio across each age group for England.
Key observations
Largest age group (population): Male # 40-44 years (154) | Female # 0-4 years (183). Source: U.S. Census Bureau American Community Survey (ACS) 2019-2023 5-Year Estimates.
When available, the data consists of estimates from the U.S. Census Bureau American Community Survey (ACS) 2019-2023 5-Year Estimates.
Age groups:
Scope of gender :
Please note that American Community Survey asks a question about the respondents current sex, but not about gender, sexual orientation, or sex at birth. The question is intended to capture data for biological sex, not gender. Respondents are supposed to respond with the answer as either of Male or Female. Our research and this dataset mirrors the data reported as Male and Female for gender distribution analysis.
Variables / Data Columns
Good to know
Margin of Error
Data in the dataset are based on the estimates and are subject to sampling variability and thus a margin of error. Neilsberg Research recommends using caution when presening these estimates in your research.
Custom data
If you do need custom data for any of your research project, report or presentation, you can contact our research staff at research@neilsberg.com for a feasibility of a custom tabulation on a fee-for-service basis.
Neilsberg Research Team curates, analyze and publishes demographics and economic data from a variety of public and proprietary sources, each of which often includes multiple surveys and programs. The large majority of Neilsberg Research aggregated datasets and insights is made available for free download at https://www.neilsberg.com/research/.
This dataset is a part of the main dataset for England Population by Gender. You can refer the same here
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United Kingdom UK: Age Dependency Ratio: % of Working-Age Population: Old data was reported at 29.037 % in 2017. This records an increase from the previous number of 28.659 % for 2016. United Kingdom UK: Age Dependency Ratio: % of Working-Age Population: Old data is updated yearly, averaging 23.904 % from Dec 1960 (Median) to 2017, with 58 observations. The data reached an all-time high of 29.037 % in 2017 and a record low of 18.068 % in 1960. United Kingdom UK: Age Dependency Ratio: % of Working-Age Population: Old data remains active status in CEIC and is reported by World Bank. The data is categorized under Global Database’s United Kingdom – Table UK.World Bank.WDI: Population and Urbanization Statistics. Age dependency ratio, old, is the ratio of older dependents--people older than 64--to the working-age population--those ages 15-64. Data are shown as the proportion of dependents per 100 working-age population.; ; World Bank staff estimates based on age distributions of United Nations Population Division's World Population Prospects: 2017 Revision.; Weighted average;
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Tools to locate the dataset tables and supporting documentation for the 2014, 2016, 2018, 2020, 2021 and 2022-based national population projections. Contains links to the principal and (where available) variant projections for the UK and constituent countries for 100 years ahead.
WorldPop produces different types of gridded population count datasets, depending on the methods used and end application.
Please make sure you have read our Mapping Populations overview page before choosing and downloading a dataset.
Bespoke methods used to produce datasets for specific individual countries are available through the WorldPop Open Population Repository (WOPR) link below.
These are 100m resolution gridded population estimates using customized methods ("bottom-up" and/or "top-down") developed for the latest data available from each country.
They can also be visualised and explored through the woprVision App.
The remaining datasets in the links below are produced using the "top-down" method,
with either the unconstrained or constrained top-down disaggregation method used.
Please make sure you read the Top-down estimation modelling overview page to decide on which datasets best meet your needs.
Datasets are available to download in Geotiff and ASCII XYZ format at a resolution of 3 and 30 arc-seconds (approximately 100m and 1km at the equator, respectively):
- Unconstrained individual countries 2000-2020 ( 1km resolution ): Consistent 1km resolution population count datasets created using
unconstrained top-down methods for all countries of the World for each year 2000-2020.
- Unconstrained individual countries 2000-2020 ( 100m resolution ): Consistent 100m resolution population count datasets created using
unconstrained top-down methods for all countries of the World for each year 2000-2020.
- Unconstrained individual countries 2000-2020 UN adjusted ( 100m resolution ): Consistent 100m resolution population count datasets created using
unconstrained top-down methods for all countries of the World for each year 2000-2020 and adjusted to match United Nations national population estimates (UN 2019)
-Unconstrained individual countries 2000-2020 UN adjusted ( 1km resolution ): Consistent 1km resolution population count datasets created using
unconstrained top-down methods for all countries of the World for each year 2000-2020 and adjusted to match United Nations national population estimates (UN 2019).
-Unconstrained global mosaics 2000-2020 ( 1km resolution ): Mosaiced 1km resolution versions of the "Unconstrained individual countries 2000-2020" datasets.
-Constrained individual countries 2020 ( 100m resolution ): Consistent 100m resolution population count datasets created using
constrained top-down methods for all countries of the World for 2020.
-Constrained individual countries 2020 UN adjusted ( 100m resolution ): Consistent 100m resolution population count datasets created using
constrained top-down methods for all countries of the World for 2020 and adjusted to match United Nations national
population estimates (UN 2019).
Older datasets produced for specific individual countries and continents, using a set of tailored geospatial inputs and differing "top-down" methods and time periods are still available for download here: Individual countries and Whole Continent.
Data for earlier dates is available directly from WorldPop.
WorldPop (www.worldpop.org - School of Geography and Environmental Science, University of Southampton; Department of Geography and Geosciences, University of Louisville; Departement de Geographie, Universite de Namur) and Center for International Earth Science Information Network (CIESIN), Columbia University (2018). Global High Resolution Population Denominators Project - Funded by The Bill and Melinda Gates Foundation (OPP1134076). https://dx.doi.org/10.5258/SOTON/WP00645
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United Kingdom ONS Projection: Population: Deaths data was reported at 836.931 Person th in 2116. This records a decrease from the previous number of 837.061 Person th for 2115. United Kingdom ONS Projection: Population: Deaths data is updated yearly, averaging 811.698 Person th from Dec 2017 (Median) to 2116, with 100 observations. The data reached an all-time high of 837.061 Person th in 2115 and a record low of 591.786 Person th in 2018. United Kingdom ONS Projection: Population: Deaths data remains active status in CEIC and is reported by Office for National Statistics. The data is categorized under Global Database’s United Kingdom – Table UK.G005: Population: Projection: Office for National Statistics.
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Context
The dataset tabulates the data for the New Britain, CT population pyramid, which represents the New Britain population distribution across age and gender, using estimates from the U.S. Census Bureau American Community Survey (ACS) 2019-2023 5-Year Estimates. It lists the male and female population for each age group, along with the total population for those age groups. Higher numbers at the bottom of the table suggest population growth, whereas higher numbers at the top indicate declining birth rates. Furthermore, the dataset can be utilized to understand the youth dependency ratio, old-age dependency ratio, total dependency ratio, and potential support ratio.
Key observations
When available, the data consists of estimates from the U.S. Census Bureau American Community Survey (ACS) 2019-2023 5-Year Estimates.
Age groups:
Variables / Data Columns
Good to know
Margin of Error
Data in the dataset are based on the estimates and are subject to sampling variability and thus a margin of error. Neilsberg Research recommends using caution when presening these estimates in your research.
Custom data
If you do need custom data for any of your research project, report or presentation, you can contact our research staff at research@neilsberg.com for a feasibility of a custom tabulation on a fee-for-service basis.
Neilsberg Research Team curates, analyze and publishes demographics and economic data from a variety of public and proprietary sources, each of which often includes multiple surveys and programs. The large majority of Neilsberg Research aggregated datasets and insights is made available for free download at https://www.neilsberg.com/research/.
This dataset is a part of the main dataset for New Britain Population by Age. You can refer the same here
Attribution 4.0 (CC BY 4.0)https://creativecommons.org/licenses/by/4.0/
License information was derived automatically
Context
The dataset tabulates the data for the New Britain, PA population pyramid, which represents the New Britain population distribution across age and gender, using estimates from the U.S. Census Bureau American Community Survey (ACS) 2019-2023 5-Year Estimates. It lists the male and female population for each age group, along with the total population for those age groups. Higher numbers at the bottom of the table suggest population growth, whereas higher numbers at the top indicate declining birth rates. Furthermore, the dataset can be utilized to understand the youth dependency ratio, old-age dependency ratio, total dependency ratio, and potential support ratio.
Key observations
When available, the data consists of estimates from the U.S. Census Bureau American Community Survey (ACS) 2019-2023 5-Year Estimates.
Age groups:
Variables / Data Columns
Good to know
Margin of Error
Data in the dataset are based on the estimates and are subject to sampling variability and thus a margin of error. Neilsberg Research recommends using caution when presening these estimates in your research.
Custom data
If you do need custom data for any of your research project, report or presentation, you can contact our research staff at research@neilsberg.com for a feasibility of a custom tabulation on a fee-for-service basis.
Neilsberg Research Team curates, analyze and publishes demographics and economic data from a variety of public and proprietary sources, each of which often includes multiple surveys and programs. The large majority of Neilsberg Research aggregated datasets and insights is made available for free download at https://www.neilsberg.com/research/.
This dataset is a part of the main dataset for New Britain Population by Age. You can refer the same here
The population of Europe was estimated to be 745 million in 2024, an increase of around 4 million when compared with 2012. Over 35 years between 1950 and 1985, the population of Europe grew by approximately 157.8 million. But 35 years after 1985 it was estimated to have only increased by around 38.7 million. Since the 1960s, population growth in Europe has fallen quite significantly and was even negative during the mid-1990s. While population growth has increased slightly since the low of -0.07 percent in 1998, the growth rate for 2020 was just 0.04 percent. Which European country has the biggest population? As of 2024, the population of Russia was estimated to be approximately 144.8 million and was by far Europe's largest country in terms of population, with Turkey being the second-largest at over 87 million. While these two countries both have territory in Europe, however, they are both only partially in Europe, with the majority of their landmasses being in Asia. In terms of countries wholly located on the European continent, Germany had the highest population at 84.5 million, and was followed by the United Kingdom and France at 69.1 million and 66.5 million respectively. Characteristics of Europe's population There are approximately 384.6 million females in Europe, compared with 359.5 million males, a difference of around 25 million. In 1950, however, the male population has grown faster than the female one, with the male population growing by 104.7 million, and the female one by 93.6 million. As of 2024, the single year of age with the highest population was 37, at 10.6 million, while in the same year there were estimated to be around 136 thousand people aged 100 or over.
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Context
The dataset tabulates the data for the London Britain Township, Pennsylvania population pyramid, which represents the London Britain township population distribution across age and gender, using estimates from the U.S. Census Bureau American Community Survey (ACS) 2019-2023 5-Year Estimates. It lists the male and female population for each age group, along with the total population for those age groups. Higher numbers at the bottom of the table suggest population growth, whereas higher numbers at the top indicate declining birth rates. Furthermore, the dataset can be utilized to understand the youth dependency ratio, old-age dependency ratio, total dependency ratio, and potential support ratio.
Key observations
When available, the data consists of estimates from the U.S. Census Bureau American Community Survey (ACS) 2019-2023 5-Year Estimates.
Age groups:
Variables / Data Columns
Good to know
Margin of Error
Data in the dataset are based on the estimates and are subject to sampling variability and thus a margin of error. Neilsberg Research recommends using caution when presening these estimates in your research.
Custom data
If you do need custom data for any of your research project, report or presentation, you can contact our research staff at research@neilsberg.com for a feasibility of a custom tabulation on a fee-for-service basis.
Neilsberg Research Team curates, analyze and publishes demographics and economic data from a variety of public and proprietary sources, each of which often includes multiple surveys and programs. The large majority of Neilsberg Research aggregated datasets and insights is made available for free download at https://www.neilsberg.com/research/.
This dataset is a part of the main dataset for London Britain township Population by Age. You can refer the same here
The resource comprises population surfaces generated from publicly available GB Census data for 1971, 1981, 1991, 2001 and 2011 to enable direct comparisons between Censuses. Population surfaces are estimates of counts of people for regular grids (with population estimates over, for example, 1km by 1km grid cells) and these can be directly compared between Censuses. Variables include age, country of birth, ethnicity, housing tenure, employment, self-reported health, overcrowding and a composite measure of deprivation over 1km by 1km cells for all Censuses where variables are available.The research will explore how the population of the UK is, or has been, geographically distributed. The project will bring a new and important perspective to debates about divisions, inequalities and the ways in which people in the UK live together or apart. It will address questions such as: are health inequalities between places greater now than in the past? What makes localities different - are they geographically distinguished more by housing tenure or health than they are by employment status or ethnicity? What areas have the greatest diversity of people and how has this changed between 1971 and 2011? To answer these questions, we will generate population surfaces from publicly available Census data for 1971, 1981, 1991, 2001 and 2011 to enable direct comparisons between Censuses. Counts of people in a variety of population sub-groups (e.g., by qualifications, age, etc) have been released from each Census for sets of small geographical areas (such as enumeration districts or output areas). This allows the mapping and analysis of geographical patterning in population groups across the UK for each Census. However, these small areas differ in size and shape between Censuses, so the 1971 small area boundaries, for example, are very different to those for 2011. This project will produce population surfaces for each Census year as a means of overcoming this problem. Population surfaces are estimates of counts of people for regular grids (with population estimates over, for example, 100m by 100m grid cells); these can be directly compared between Censuses. So, once these population surfaces are available we will be able to consider how localities have changed and in what ways. This new population surface resource will be made freely available so that users can explore these changes for themselves and also consider in more depth the results we produce. We will use this resource to provide the first systematic review of how the population of the UK has changed over the last 40 years. It will show how population groups in the UK are geographically distributed and it will assess, in detail, how far different localities (for example, within central Scotland) or regions (for example, south east England or north west England) are becoming more similar or more different to one another in terms of their population characteristics. The project will also consider how the relationships between population groups have changed across time. For example, with a consistent geography, it will be possible to assess which small area localities have very high rates of unemployment together with large proportions of social rented households, and how the characteristics of these localities changed between 1971 and 2011. We will also be able to identify which population characteristics most strongly distinguish particular areas. As an example, the population in some localities in north west England may be very similar in terms of levels of poor health, unemployment and housing tenure, but differ in terms of the number of single person households or the average number of dependent children. The project will explore these differences in detail and, for the first time, construct a detailed profile of the geographical distribution of individual population groups and the multiple characteristics of areas in combination. The population surface resource will be invaluable to any users interested in the population geography of the UK, while the results of our analysis of population distributions will enrich our understanding of the ways in which the population of the UK has changed over the last 40 years. The resource was generated using small area (enumeration district and output area) Census data for Britain. The counts for these areas were reallocated to 1km by 1km grid cells using information on postcode intensity to determine how many people in each population group (e.g., unemployed people) should be transferred from the original zones to the 1km by 1km cells.
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Population of the very elderly (including centenarians) by gender, single year of age (90 to 104) and by age groups (90-99, 100+ and 105+) for England & Wales. Source agency: Office for National Statistics Designation: Experimental Official Statistics Language: English Alternative title: Population Estimates of the very elderly (experimental)
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United Kingdom ONS Projection: Population: Deaths: Female data was reported at 414.083 Person th in 2116. This records a decrease from the previous number of 414.131 Person th for 2115. United Kingdom ONS Projection: Population: Deaths: Female data is updated yearly, averaging 405.107 Person th from Dec 2017 (Median) to 2116, with 100 observations. The data reached an all-time high of 417.696 Person th in 2061 and a record low of 302.385 Person th in 2018. United Kingdom ONS Projection: Population: Deaths: Female data remains active status in CEIC and is reported by Office for National Statistics. The data is categorized under Global Database’s United Kingdom – Table UK.G005: Population: Projection: Office for National Statistics.
Different countries have different health outcomes that are in part due to the way respective health systems perform. Regardless of the type of health system, individuals will have health and non-health expectations in terms of how the institution responds to their needs. In many countries, however, health systems do not perform effectively and this is in part due to lack of information on health system performance, and on the different service providers.
The aim of the WHO World Health Survey is to provide empirical data to the national health information systems so that there is a better monitoring of health of the people, responsiveness of health systems and measurement of health-related parameters.
The overall aims of the survey is to examine the way populations report their health, understand how people value health states, measure the performance of health systems in relation to responsiveness and gather information on modes and extents of payment for health encounters through a nationally representative population based community survey. In addition, it addresses various areas such as health care expenditures, adult mortality, birth history, various risk factors, assessment of main chronic health conditions and the coverage of health interventions, in specific additional modules.
The objectives of the survey programme are to: 1. develop a means of providing valid, reliable and comparable information, at low cost, to supplement the information provided by routine health information systems. 2. build the evidence base necessary for policy-makers to monitor if health systems are achieving the desired goals, and to assess if additional investment in health is achieving the desired outcomes. 3. provide policy-makers with the evidence they need to adjust their policies, strategies and programmes as necessary.
The survey sampling frame must cover 100% of the country's eligible population, meaning that the entire national territory must be included. This does not mean that every province or territory need be represented in the survey sample but, rather, that all must have a chance (known probability) of being included in the survey sample.
There may be exceptional circumstances that preclude 100% national coverage. Certain areas in certain countries may be impossible to include due to reasons such as accessibility or conflict. All such exceptions must be discussed with WHO sampling experts. If any region must be excluded, it must constitute a coherent area, such as a particular province or region. For example if ¾ of region D in country X is not accessible due to war, the entire region D will be excluded from analysis.
Households and individuals
The WHS will include all male and female adults (18 years of age and older) who are not out of the country during the survey period. It should be noted that this includes the population who may be institutionalized for health reasons at the time of the survey: all persons who would have fit the definition of household member at the time of their institutionalisation are included in the eligible population.
If the randomly selected individual is institutionalized short-term (e.g. a 3-day stay at a hospital) the interviewer must return to the household when the individual will have come back to interview him/her. If the randomly selected individual is institutionalized long term (e.g. has been in a nursing home the last 8 years), the interviewer must travel to that institution to interview him/her.
The target population includes any adult, male or female age 18 or over living in private households. Populations in group quarters, on military reservations, or in other non-household living arrangements will not be eligible for the study. People who are in an institution due to a health condition (such as a hospital, hospice, nursing home, home for the aged, etc.) at the time of the visit to the household are interviewed either in the institution or upon their return to their household if this is within a period of two weeks from the first visit to the household.
Sample survey data [ssd]
SAMPLING GUIDELINES FOR WHS
Surveys in the WHS program must employ a probability sampling design. This means that every single individual in the sampling frame has a known and non-zero chance of being selected into the survey sample. While a Single Stage Random Sample is ideal if feasible, it is recognized that most sites will carry out Multi-stage Cluster Sampling.
The WHS sampling frame should cover 100% of the eligible population in the surveyed country. This means that every eligible person in the country has a chance of being included in the survey sample. It also means that particular ethnic groups or geographical areas may not be excluded from the sampling frame.
The sample size of the WHS in each country is 5000 persons (exceptions considered on a by-country basis). An adequate number of persons must be drawn from the sampling frame to account for an estimated amount of non-response (refusal to participate, empty houses etc.). The highest estimate of potential non-response and empty households should be used to ensure that the desired sample size is reached at the end of the survey period. This is very important because if, at the end of data collection, the required sample size of 5000 has not been reached additional persons must be selected randomly into the survey sample from the sampling frame. This is both costly and technically complicated (if this situation is to occur, consult WHO sampling experts for assistance), and best avoided by proper planning before data collection begins.
All steps of sampling, including justification for stratification, cluster sizes, probabilities of selection, weights at each stage of selection, and the computer program used for randomization must be communicated to WHO
STRATIFICATION
Stratification is the process by which the population is divided into subgroups. Sampling will then be conducted separately in each subgroup. Strata or subgroups are chosen because evidence is available that they are related to the outcome (e.g. health, responsiveness, mortality, coverage etc.). The strata chosen will vary by country and reflect local conditions. Some examples of factors that can be stratified on are geography (e.g. North, Central, South), level of urbanization (e.g. urban, rural), socio-economic zones, provinces (especially if health administration is primarily under the jurisdiction of provincial authorities), or presence of health facility in area. Strata to be used must be identified by each country and the reasons for selection explicitly justified.
Stratification is strongly recommended at the first stage of sampling. Once the strata have been chosen and justified, all stages of selection will be conducted separately in each stratum. We recommend stratifying on 3-5 factors. It is optimum to have half as many strata (note the difference between stratifying variables, which may be such variables as gender, socio-economic status, province/region etc. and strata, which are the combination of variable categories, for example Male, High socio-economic status, Xingtao Province would be a stratum).
Strata should be as homogenous as possible within and as heterogeneous as possible between. This means that strata should be formulated in such a way that individuals belonging to a stratum should be as similar to each other with respect to key variables as possible and as different as possible from individuals belonging to a different stratum. This maximises the efficiency of stratification in reducing sampling variance.
MULTI-STAGE CLUSTER SELECTION
A cluster is a naturally occurring unit or grouping within the population (e.g. enumeration areas, cities, universities, provinces, hospitals etc.); it is a unit for which the administrative level has clear, nonoverlapping boundaries. Cluster sampling is useful because it avoids having to compile exhaustive lists of every single person in the population. Clusters should be as heterogeneous as possible within and as homogenous as possible between (note that this is the opposite criterion as that for strata). Clusters should be as small as possible (i.e. large administrative units such as Provinces or States are not good clusters) but not so small as to be homogenous.
In cluster sampling, a number of clusters are randomly selected from a list of clusters. Then, either all members of the chosen cluster or a random selection from among them are included in the sample. Multistage sampling is an extension of cluster sampling where a hierarchy of clusters are chosen going from larger to smaller.
In order to carry out multi-stage sampling, one needs to know only the population sizes of the sampling units. For the smallest sampling unit above the elementary unit however, a complete list of all elementary units (households) is needed; in order to be able to randomly select among all households in the TSU, a list of all those households is required. This information may be available from the most recent population census. If the last census was >3 years ago or the information furnished by it was of poor quality or unreliable, the survey staff will have the task of enumerating all households in the smallest randomly selected sampling unit. It is very important to budget for this step if it is necessary and ensure that all households are properly enumerated in order that a representative sample is obtained.
It is always best to have as many clusters in the PSU as possible. The reason for this is that the fewer the number of respondents in each PSU, the lower will be the clustering effect which
In 2024, the population of the United Kingdom reached 69.3 million, compared with 68.5 million in 2023. The UK population has more than doubled since 1871 when just under 31.5 million lived in the UK and has grown by around 10.4 million since the start of the twenty-first century. For most of the twentieth century, the UK population steadily increased, with two noticeable drops in population occurring during World War One (1914-1918) and in World War Two (1939-1945). Demographic trends in postwar Britain After World War Two, Britain and many other countries in the Western world experienced a 'baby boom,' with a postwar peak of 1.02 million live births in 1947. Although the number of births fell between 1948 and 1955, they increased again between the mid-1950s and mid-1960s, with more than one million people born in 1964. Since 1964, however, the UK birth rate has fallen from 18.8 births per 1,000 people to a low of just 10.2 in 2020. As a result, the UK population has gotten significantly older, with the country's median age increasing from 37.9 years in 2001 to 40.7 years in 2022. What are the most populated areas of the UK? The vast majority of people in the UK live in England, which had a population of 58.6 million people in 2024. By comparison, Scotland, Wales, and Northern Ireland had populations of 5.5 million, 3.2 million, and 1.9 million, respectively. Within England, South East England had the largest population, at over 9.6 million, followed by the UK's vast capital city of London, at almost 9.1 million. London is far larger than any other UK city in terms of urban agglomeration, with just four other cities; Manchester, Birmingham, Leeds, and Glasgow, boasting populations that exceed one million people.