Explanation of the data presented

This dashboard shows many figures that give information about how the coronavirus situation is developing in the Netherlands. On this page we explain the sources that these figures are based on, and how the figures are arrived at.

Vaccinations

Where do these figures come from?
RIVM delivers data on the number of vaccine doses administered on Tuesdays and Thursdays. This data is not currently available as an open data file.

RIVM delivers weekly data on the vaccination grade and the number of people who have been vaccinated. These figures are published on the dashboard on Wednesdays. The figures on the total vaccination coverage in the Netherlands (18 years and older / 12 years and older) come from a different source than the figures on the vaccination coverage per age group and the vaccination coverage per municipality.

The figures on the total vaccination coverage in the Netherlands are the calculated figures that RIVM provides to ECDC. These data are not yet available as an open data file.

See the vaccination figures on the RIVM website

The figures on vaccination coverage by age group are not yet available as an open data file.

The figures on vaccination coverage per municipality are available as an open data file.

See RIVM's open data file on vaccination coverage per municipality

See RIVM's description of data set on vaccination coverage per municipality

How are these figures determined?

Vaccine doses administered
The number of doses administered is drawn from data that the municipal health services (GGDs) pass on to RIVM. RIVM records the number of doses administered by GGD vaccination centres, hospitals, healthcare institutions and general practitioners (GPs) in its central COVID Vaccination Information and Monitoring System (CIMS). However, the CIMS data is still incomplete, as GPs and institutions have not yet reported a small proportion of the doses that have been administered to RIVM.

Despite the incomplete data, we want to depict the number of vaccine doses administered and the number of people vaccinated as accurately as possible. To this end, the dashboard shows RIVM’s estimates of the number of vaccine doses administered in healthcare institutions and GP practices, and the number of people vaccinated. The estimates are based on the number of vaccine doses that have been delivered to the locations where injections are given.

See RIVM’s explanation of how these estimates are calculated
Underneath the table showing the vaccination figures is a green bar. Click on ‘More information’ for a detailed explanation.

The calculated number of doses administered in general practices is currently unchanged, as the RIVM is recalculating this number. Once the calculation is complete, the number of doses administered in general practices will be updated.

Vaccination coverage
So far, RIVM bases its figures on the total national vaccination coverage on the calculated number of doses administered. This is because the reported vaccinations in the registration system CIMS were not complete enough earlier. As the vaccination coverage is partly based on calculations, the actual coverage may be slightly different.

The figures for vaccination coverage by age group and vaccination coverage per municipality come from CIMS. RIVM registers in CIMS how many people have started and how many people have completed their vaccinations. A vaccination has started when someone has had the first dose. A vaccination is completed when someone has had the last necessary dose. Depending on the type of vaccine, this may be immediately after the first dose (Janssen vaccine) or only after the second dose (other vaccines). If someone has had the last necessary dose, this person is fully vaccinated.

On the dashboard, under 'Turnout 1st dose', we show how many people have received at least one dose. We also show how many people have had all the necessary doses and are therefore fully vaccinated.

If the vaccination coverage is very high or very low in a certain population group, this can be traced back to individuals. For reasons of privacy, the dashboard in those cases therefore shows 'more than 95%' or 'less than 5%' instead of an exact percentage.

Vaccination coverage by age group and per municipality actually higher
The vaccination coverage by age group and per municipality is in reality higher than shown on the dashboard. There are four reasons for this:

General practitioners and institutions have not yet reported to CIMS a small proportion of the vaccinations they have carried out. The figures on the number of vaccinated people are therefore not complete.
CIMS only lists the vaccinations given to people who have given permission to register their vaccination.
For the BioNTech/Pfizer, Moderna and AstraZeneca vaccines, two shots are normally needed for a full vaccination. But people who have had coronavirus are already fully vaccinated after one dose. On the dashboard, these people still do not count as fully vaccinated. It is not yet possible to distinguish in the data between people who need two doses and people who only need one dose because they have had coronavirus. This is being worked on.
People who have had two doses with two different vaccines do not yet count as fully vaccinated on the dashboard. For example, this concerns people who have had a first dose with the AstraZeneca vaccine at the GP and a second dose with BioNTech/Pfizer or Moderna at the GGD.

Waiting time after last vaccine dose
The dashboard counts someone as fully vaccinated immediately after the last vaccine dose was administered. The dashboard therefore does not take into account the waiting time after the last dose. In the Netherlands, there is a waiting period of four weeks for the Janssen vaccine and a waiting period of two weeks for other vaccines. Only then does the vaccination provide sufficient protection against COVID-19 and does it count as a valid corona certificate.

Delivered and available doses & doses administered in total
The graph 'Delivered and available doses & doses administered in total' shows the total number of vaccines that have been delivered and checked. Newly delivered doses are always first subjected to a number of checks. After this, the doses can be administered. In calculating the number of doses, RIVM takes 1% wastage into account. Vaccines for the Caribbean part of the Kingdom (Aruba, Curaçao, St Maarten, Bonaire, Saba and St Eustatius) are not included in the figures. In addition, vaccines that are donated to other countries, to Suriname for example, are not included.

RIVM assumes that each vaccine vial contains a specific number of doses – BioNTech/Pfizer: 6.9 doses per vial; Moderna: 10 doses per vial; AstraZeneca: 11 doses per vial; and Janssen: 5 doses per vial. This may differ from the manufacturer’s instructions for some vaccines.

The numbers shown in the graph 'Delivered and available doses & doses administered in total' are lower than elsewhere on this page, because the other figures and graphs do not deduct for wastage and also include the vaccines for the Caribbean.

Changes in the figures
Expected doses
Until 15 September 2021, the graph 'Delivered and checked doses & doses administered in total' showed the expected number of doses administered for the coming weeks. Previously, the expected number was calculated by looking at how many doses are delivered to the locations where injections are given. All doses delivered were used immediately in the following days. This is no longer the case. We receive more vaccines than we immediately need. It is therefore no longer possible to calculate the expectation accurately in this way and it is therefore no longer shown in the graph.

Improved estimate of number of doses
The number of doses administered by healthcare institutions and GPs between 6 January 2021 and 27 April 2021 was found to have been incorrectly estimated due to a programme error in the RIVM’s calculation model. On 29 April 2021, these figures were corrected retroactively on the dashboard. See extensive explanation on RIVM’s website.

Less wastage
Up to 13 April 2021, RIVM took 5% wastage into account. Data from the GGD shows that 1% is a better assessment of wastage at healthcare institutions and in general practice. This was adjusted retroactively on 13 April 2021.

Missing doses added
On 27 July 2021, approximately 160,000 doses were processed that did not get through to the RIVM. This was added to the dashboard on that day.

Improved data
The GGD has removed appointments that were cancelled or that did not result in vaccination from its data set. It has also corrected the data for people who received doses of two different vaccines. Around 160,000 doses have been removed from the data set. The improved data set includes the data up to and including 8 August 2021. The figures on the dashboard were updated on 10 August 2021.

Where do these figures come from?
The figures come from RIVM’s behavioural survey. RIVM provides these figures as open data files.

How are these figures determined?
The figures represent the combined number of survey participants who have already been vaccinated or who want to be vaccinated. As part of the behavioural survey participants are asked whether they have received a letter inviting them to get vaccinated. The ‘percentage of people already vaccinated or willing to be’ shown on the dashboard reflects the sum total of participants who gave one of the following four answers: (1) received letter and already vaccinated; (2) received letter and made an appointment; (3) received letter and intend to make an appointment; and (4) have not received letter but want to be vaccinated.

The participants in the survey are as good a reflection of the population as possible. However, it is known that certain groups are not well represented in the survey, such as people with a migration background. Willingness to be vaccinated is lower among these groups. If these groups were well represented in the survey, the figures would probably be slightly lower, according to RIVM.

See the Explanation of the data presented for information on the full behavioural survey

Changes in the figures
Up to and including the 11th round of the survey, which was conducted from 20 to 26 April 2021, only participants who had not yet received an invitation letter were asked whether they wanted to be vaccinated against COVID 19. As more people began to receive their letters, this question began to yield misleading results.

Starting with the 12th round of the survey, conducted from 11 to 17 May 2021, this question was modified as described above in ‘How are these figures determined?’

Other figures on willingness to be vaccinated
There are also other recurrent surveys that measure willingness to be vaccinated, e.g. by I&O research and Ipsos. RIVM is also conducting another survey (WP3) that measures willingness to be vaccinated, but this survey is done less often. Statistics Netherlands (CBS) conducts a poll every three months.

The results of these surveys can differ. This is partly because RIVM's behavioural survey only includes people who clearly answer ‘yes’ to the question of whether they want to be vaccinated, while other surveys include all people who ‘probably’ want to be vaccinated. The date people were surveyed may also influence their willingness to be vaccinated as this changes over time.

Where do these figures come from?
Data on deliveries and doses in stock is provided by the National Institute for Public Health and the Environment (RIVM). This is not yet available as an open data file.

How are these figures determined?
Deliveries
The ‘Deliveries’ graph on the dashboard shows the number of doses that the Netherlands has received and expects to receive. RIVM assumes that each vaccine vial contains a specific number of doses – BioNTech/Pfizer: 6.9 doses per vial; Moderna: 10 doses per vial; AstraZeneca: 11 doses per vial; and Janssen: 5 doses per vial. This may differ from the manufacturer’s instructions for some vaccines.

Doses in stock per type of vaccine
In the graph ‘Doses in stock per type of vaccine,’ the dashboard shows the total and available stock per type of vaccine at the central storage site. The total stock covers stock that is available and stock that is not yet available. The stock that is not yet available comprises vaccines that still have to be checked.

The size of the stock fluctuates: shortly after a new delivery, the total stock of a vaccine is relatively high; just before the next delivery is released from quality control, the available stock is low.

Hospitals

Where do these figures come from?
Number of hospital admissions
The figures on number of hospital admissions are supplied by the National Institute for Public Health and the Environment (RIVM). This data is available in the form of an open data file. As of 1 July 2021, some hospitals provide data twice a week in stead of daily. Therefore the data are most complete on Wednesdays and Saturdays.

Occupancy of regular hospital beds
Figures on occupancy of regular hospital beds, excluding ICU beds, are provided by the LCPS. This data is available in the form of an open data file. As of 1 July 2021, the LCPS bases the weekend figures on (historical) data known to the LCPS.

How are these figures determined?
Number of hospital admissions
RIVM bases its calculations on information that is collected by Stichting NICE (the National Intensive Care Evaluation Registry). Stichting NICE registers the COVID-19 patients admitted to Intensive Care Units (ICU) and to hospital wards. The figures include both patients who are admitted to hospital wards and patients who are admitted directly to ICU.

Admissions are not always reported on the day of admission. The dashboard shows the number of admissions reported on one day. Even though reports are missing on a daily basis and late reports from previous days are added, this figure still gives a good idea of the daily number of hospital admissions.

We use data from NICE, even though the LCPS has been collecting data on new hospital admissions since October 2020. This is because the LCPS only provides aggregated data. For example, they do not provide any information on patients’ age or sex. This means that the LCPS data set is too limited for this dashboard, and cannot be used by RIVM.

Occupancy of regular hospital beds
The LCPS registers the number of beds on regular hospital wards that are occupied by COVID-19 patients. Figures from before 1 June 2020 may be less reliable, as the LCPS was still in the process of setting up its registration system at that time.

Changes in the figures
Up to 16 December 2020 the dashboard used data from the OSIRIS database, which is provided primarily by the municipal health services (GGDs). However, OSIRIS suffers from significant underreporting of hospital admissions as the GGDs are no longer always informed when COVID-19 patients are admitted to hospital. The NICE data set is more complete, but its definition of ‘hospital admission’ is also broader. Whereas the OSIRIS data set includes only patients admitted to hospital due to COVID-19, the NICE data set also includes hospital patients who have COVID-19 but who were admitted for another reason.

Correction
Due to a correction in the registration system of the Albert Schweitzer Hospital (region Dordrecht), 355 hospital admissions spread over the period from January 1, 2021 to July 27, 2021 were incorrectly reported. The numbers are lower in reality. The numbers are retroactively updated on the dashboard on July 28, 2021.

Differences between the figures
There are differences between the LCPS and NICE registration systems. The LCPS system focuses on bed occupancy (capacity), the NICE system focuses on patients. An increase in occupancy does not fully reflect the number of new patients. When a patient is discharged from hospital, the bed does not immediately become available. It is also possible that one bed may have several occupants over the course of a day. Each of these data sets contains different information and is used for different purposes. These figures are therefore not directly interchangeable.

Where do these figures come from?
ICU admissions
The figures on new admissions to ICU are supplied by RIVM.This data is available in the form of an open data file. As of 1 July 2021, some hospitals provide data twice a week in stead of daily. Therefore the data are most complete on Wednesdays and Saturdays.

ICU bed occupancy
The figures on ICU bed occupancy are supplied by the LCPS. This data is available in the form of an open data file. As of 1 July 2021, the LCPS bases the weekend figures on (historical) data known to the LCPS.

How are these figures determined?
ICU admissions
RIVM bases its calculations on information that is collected by Stichting NICE (the National Intensive Care Evaluation Registry). Stichting NICE registers the COVID-19 patients admitted to Intensive Care Units (ICU) and hospital wards. ICU admissions reported via RIVM also include any admissions of Dutch patients to ICUs in German hospitals, as the main purpose of this figure is to track the spread of COVID-19 and the effect on the course of the disease.

ICU bed occupancy
The LCPS data set includes both the number of ICU beds occupied by COVID-19 patients, and the number of ICU beds occupied by other patients. The percentage of ICU beds occupied by COVID-19 patients is calculated by dividing the number of ICU beds occupied by COVID-19 patients by the total number of occupied ICU beds. ICU bed occupancy does not include any Dutch patients in German ICUs, as the main purpose of this figure is to show the capacity of Dutch ICUs.

Figures from before 1 June 2020 may be less reliable as the LCPS was still in the process of setting up its registration system at that time.

Changes in the figures
Due to a correction in the registration system of the Albert Schweitzer Hospital (region Dordrecht), 30 ICU admissions spread over the period from January 1, 2021 to July 27, 2021 were incorrectly reported. The numbers are lower in reality. The numbers are retroactively updated on the dashboard on July 28, 2021.

Infections

Where do these figures come from?
The figures on the number of positive tests (confirmed cases) are supplied by the National Institute for Public Health and the Environment (RIVM). This data is available as open data.

How are these figures determined?
The figure shows the number of positive tests reported to RIVM in the preceding 24 hours, up to 10.00 on the day of publication of the figures. The date attributed to positive tests is the date on which RIVM was notified by the municipal health authority (GGD). This is not the same as the date on which people are tested.

Doctors and laboratories are required to report cases of infectious disease to the GGD. However, coronavirus tests are also carried out by commercial organisations and individuals. The results of these tests are not always reported to the GGD, or the notification is not counted as the test used does not meet RIVM standards. Commercial testing organisations are required to report positive test results to the GGD. This means that the daily number of confirmed cases reported on the dashboard may not give the complete picture. This should be kept in mind when interpreting these figures.

Part of the notification process is done manually. Sometimes the GGDs will not have reported all newly confirmed cases at the moment that RIVM compiles the figures for the preceding 24 hours. Missing notifications are passed on at a later time. Missing or delayed notifications can skew the daily figures. The rolling average filters out this type of fluctuation, and therefore often gives a better picture of the number of infections.

Changes in the figures
RIVM can also retrospectively correct data that has already been published. These corrections are processed in the open data file and incorporated into the dashboard. The data file registers cases at safety region and municipality level. In order to calculate data at national level we add all notified cases together. Some notified cases cannot be linked to a particular municipality/safety region, as this information is missing from the data file. These cases cannot therefore be shown at those levels, but they are included in the national figures.

Growth rate
The growth rate (or G rate) is a percentage that expresses the change in the number of positive tests in the last 7 days relative to the number of positive tests in the preceding 7 days. To calculate the growth rate, data must be available for 14 consecutive days (the previous 7 days + the 7 days preceding that).

The growth rate is calculated by the Ministry of Health, Welfare and Sport based on data from RIVM. All historical growth rates are recalculated daily, so that any corrections made by RIVM to the number of positive tests are incorporated into the historical trend of the growth rate. The growth rate is calculated in line with the method used by research institute IPSE Studies. The growth rate was introduced by the Dutch newspaper de Volkskrant.

Where do these figures come from?
The National Institute for Public Health and the Environment (RIVM) supplies open data on positive test results via GGD test locations.

How are the figures determined?
The percentage of tests that have a positive result is based on tests conducted by the GGD and for which the results are known. The seven-day rolling average is calculated with a two-day delay. This is because the results of tests conducted in the last 48 hours may not yet be available. This way we can be sure that most of the results are available and that the percentage of positive tests is accurately represented.

Changes in the figures
As of 1 July 2021 people who are planning to travel abroad can also be tested at GGD test centres. Before 10 August these people’s test results were included in the same data set as the results of people being tested by the GGD for other reasons. As of 10 August travellers’ test results are no longer included. Around 200,000 test results have been removed from the data set. The figures on the dashboard for the period between 1 July and 10 August have been adjusted accordingly. As a result, the percentage of positive test results in that period is higher than previously indicated. The increase is 2 to 3 percentage points, depending on the day.

On 7 September, 2021, we added an additional notification in the graph "Percentage of GGD positive test results, over time". The percentage of positive tests is no longer clear and unambiguous to interpret and compare over time. This is partly due to a recent increase in testing at walk-in test sites not requiring an appointment for students during introduction weeks, testing of returning travellers, and testing for confirmation after a positive self-test.

Where do these figures come from?
Twice a week (on Tuesdays and Fridays), the National Institute for Public Health and the Environment (RIVM) supplies open data on the reproduction number. The reproduction number (R) is not an exact value but a reliable calculation.

How are the figures determined?
RIVM uses the reported number of daily positive test results to calculate R. In most cases, the day on which symptoms first presented is known. In other cases, this date can be estimated. If someone has no symptoms, RIVM will use the date on which they would normally have experienced symptoms for the first time.

Depicting the number of coronavirus cases according to the first day of symptoms gives a clear picture of whether the number of transmissions is increasing, at its peak or decreasing. In order to calculate R, it is also necessary to know the length of time between the first day of symptoms of a new case and the first day of symptoms of the person who infected them. This has been calculated to be 4 days on average, based on coronavirus cases reported to the municipal health service (GGD). This information is then used to calculate the reproduction number.

See RIVM’s explanation of how the reproduction number is calculated

How up to date are the figures?
The most up-to-date value of R provided on the coronavirus dashboard at any given time is always from at least two weeks ago. Calculations of R using data from less than 14 days ago could provide an indication of what the definitive value may be, but are not reliable predictors. The more recent the day, the less reliable the figure is since not all the data for that day is available yet.

Changes in the figures
Until 11 June 2020 R was calculated on the basis of COVID-19 hospital admissions as large-scale testing was not yet underway. Until 2 November 2020, the graph showing the progression of R over time did not give a value of R for the most recent two weeks but did give a projection of this value in the form of a bandwidth. As of 3 November, the dashboard graph no longer displays this bandwidth.

Where do these figures come from?
Number of COVID-19 deaths
The mortality figures are supplied by the National Institute for Public Health and the Environment (RIVM). This data is available in the form of an open data file.

How are these figures determined?
Number of COVID-19 deaths
This is the number of COVID-19 patients whose deaths have been reported to RIVM in the past 24 hours. The date shown is the date on which RIVM was notified by the municipal health authority (GGD). This may not be the same as the date on which deaths occurred. The actual number of deceased COVID-19 patients is higher than the number of deaths reported by RIVM because there is no requirement to report COVID-19-related deaths.

Where do these figures come from?
General data on mortality is provided by the national office Statistics Netherlands (CBS).

How are the figures determined?
Statistics Netherlands (CBS) weekly publishes the total number of deaths on Friday and compares this number with the expected number of deaths. Excess mortality occurs when more people die than expected. So expected mortality is the mortality you would expect if there had been no corona epidemic. This takes into account aging, migration, et cetera, and compares it with the seasonal pattern from the 2015-2019 period. The predicted number of deaths per week have been taken from the mortality projections made once every year by Statistics Netherlands.

The expected number of deaths has a bandwidth with an upper and lower limit (interval). Statistics Netherlands only speaks of excess mortality if the number of deaths is above the interval. Within the interval, it may be an ordinary fluctuation.

Read more about how Statistics Netherlands determines excess mortality and expected mortality

Changes in news item
As of 9 July, Statistics Netherlands (CBS) will no longer publish the news item about mortality on a weekly base. From that date, the news item will be published monthly. New figures will still appear weekly.

Where do the figures come from?
The figures on coronavirus variants are supplied by the National Institute for Public Health and the Environment (RIVM) as open data.

How are the figures determined?
The National Institute for Public Health and the Environment (RIVM) has been studying coronavirus variants in the Netherlands through pathogen surveillance since late 2020. Every week RIVM analyses about 1,500 random test samples containing coronavirus that it receives from various labs across the country.
On the basis of this analysis, RIVM can determine what percentage of infections each variant is responsible for and, from there, predict the speed at which the different variants are likely to spread. This enables RIVM to estimate what percentage of future infections will be caused by which variant. As new data arrives each week, it is checked against these predictions. This helps make future predictions more and more reliable. The figures shown on the Dashboard are not RIVM’s predictions, but rather the data from the pathogen surveillance. Preparing and analysing the samples and processing the data takes time. The figures for the most recent weeks are therefore incomplete and, because of this, we do not show them on the Dashboard. As a result, the percentage for a given variant as reported by RIVM often differs from what is shown on the Dashboard at that time. The media also tends to report RIVM’s predictions.

The data gathered from pathogen surveillance is updated every Friday. Figures may change from week to week compared to what was previously published, generally as a result of changes to the date a sample was collected or other changes related to the sample in the registration system. Data from the most recent weeks is incomplete and is updated in future publications as more information becomes available. In other words, the data on the dashboard is updated retroactively.

Variants on the dashboard
The table on the dashboard shows the variants of concern and the variants of interest. The European Centre for Disease Prevention and Control (ECDC) and the World Health Organization (WHO) consider a variant to be a variant of concern if it spreads more easily, makes people more sick or if vaccines are less effective against the variant. A variant of interest is a variant that has been traced to multiple infections in a particular setting or cluster, or that has been detected in multiple countries.

The graph on the dashboard only shows the ECDC variants of concern. These variants are monitored because of their potential risk. RIVM follows the ECDC and the WHO guidelines in this respect. The other variants detected (the variants of interest) are shown in the table under ‘Other variants’.

Read more about coronavirus variants on the RIVM website.

Where do these figures come from?
RIVM provides these figures as open data.

How are the figures determined?
The GGD carries out contact tracing in relation to people who have tested positive for coronavirus. This includes looking at the setting in which someone may have become infected. RIVM has defined 21 possible settings. For the overview on the dashboard these 21 settings have been grouped into eight categories. The overview below shows the eight categories and the settings they cover.

1. At home and visiting

Home setting (household members, including non-cohabiting partners)
Home visits (by or to family, friends, etc.)

2. Work

Work setting

3. School and childcare

School and childcare

4. Healthcare

Primary healthcare / family doctor (GP)
Secondary healthcare / hospital
Other healthcare
Nursing home or residential care home for the elderly
Residential care home for people with disabilities
Other residential care home
Daycare for the elderly and people with disabilities

5. Gatherings

Celebrations (party, birthday, drinks, wedding, etc.)
Student society/activities
Leisure (e.g. sports club)
Religious gatherings
Choir
Funeral

6. Travel

Fellow traveller / travel / holiday
Flights

7. Restaurant, café or bar

Restaurant, café or bar

8. Other

Other

If many people test positive in a safety region, this can put severe pressure on the contact tracing process. This may mean that the GGD cannot carry out regular contact tracing and that there is therefore insufficient data for that region. In this case there will be no information on the dashboard for that region for that particular period.

Watch the GGD GHOR video (in Dutch) about contact tracing

Vulnerable groups

Where do these figures come from?
The figures on nursing home care are provided by the National Institute for Public Health and the Environment (RIVM). RIVM supplies the figures as an open data file.

How are these figures determined?
Residents testing positive
RIVM counts a person as a nursing home resident if, according to the OSIRIS central database, they are resident in a nursing home or a similar residential care centre for the elderly. When someone tests positive for coronavirus, the municipal health service (GGD) asks if that person is resident in a nursing home or residential care home for the elderly. If this information is unavailable, RIVM determines whether the person is a nursing home resident using the old definition (see below under ‘Changes in the figures’).

Infected locations
RIVM has determined the total number of nursing home locations per safety region using the list provided by Zorgkaart Nederland. RIVM counts nursing homes with the same postcode as one nursing home location. The same method is used to determine the number of infected locations. It is necessary to know the total number of nursing home locations per safety region in order to calculate the percentage of nursing home locations that are infected. To calculate the total number of nursing home locations nationwide, we add up the totals of all safety regions.

Deceased residents
We show the number of deaths among nursing home residents by the date of death. If we do not know the date of death, which is sometimes the case, we do not show the death on the dashboard.

National figures
Sometimes the data provided cannot be linked to a specific safety region. This means that the numbers at national level may sometimes be higher than the total of the numbers at safety region level.

Average over 7 days
The graph showing the number of confirmed cases among nursing home residents and the graph showing the number of residents who have died shows the average over 7 days.

View the description of the 'averages over the past seven days' below

Changes in the figures
The definition RIVM used up to the end of September 2020 to determine if someone who had tested positive was a nursing home resident (see below under ‘Old definition’) resulted in a significant overestimate of the number of infected nursing home locations. From 1 July 2020, the GGDs register whether a newly-infected person is a nursing home resident. RIVM has recalculated the figures on the dashboard from 1 July 2020 onwards using this data, which now gives a much better picture of the actual number of infected nursing homes and nursing home residents. For reports of confirmed cases amongst residents without a stated first day of illness, the RIVM determines a calculated first day of illness. This calculation method has been adjusted from 16 July 2021. The figures for the number of infected locations have been retroactively adjusted on the dashboard.

Old definition
According to the old definition, a person was considered a nursing home resident if they met one of the following conditions:

OSIRIS could link the person to a registered nursing home or residential care home for the elderly on the basis of a postcode;
OSIRIS could link the person to a place where infection may have occurred to a setting labelled ‘nursing home’ or similar on the basis of a postcode;
OSIRIS could link the person to a nursing home or residential care home for the elderly on the basis of another term in the system.

In addition, the person:

had to be over 70 years old
was not a health worker, and
was not employed.

Where do these figures come from?
The figures on disability care are provided by the National Institute for Public Health and the Environment (RIVM). RIVM supplies the figures as an open data file.

How are these figures determined?
Confirmed cases among residents
From 1 July 2020, the GGDs registers whether a newly-infected person is resident in a disability care home. RIVM considers a person to be a disability care home resident if they are registered as such in the central OSIRIS database. If this is not known, RIVM counts the person as a disability care home resident if they are not a health worker and:

the location of the infection is a disability care home, or
they can be linked to the disability care home on the basis of information given in free text fields.

Locations
The word ‘locations’ refers to the 2,586 care homes in the Netherlands that are registered by Zorgkaart Nederland as providing residential care to people with disabilities. The total number of locations per safety region is provided by RIVM. Locations with the same postcode are counted as one location. The same method is used to determine the number of infected locations. It is necessary to know the total number of locations per safety region in order to calculate the percentage of locations that are infected. To calculate the total number of locations nationwide, we add up the totals of all safety regions.

Deceased residents
We show the number of deaths among disability care home residents by the date of death. If we do not know the date of death, which is sometimes the case, we do not show the death on the dashboard.

National figures
Sometimes the data provided cannot be linked to a specific safety region. This means that the numbers at national level may sometimes be higher than the total numbers at safety region level.

Average over 7 days
The graph showing the number of confirmed cases among residents and the graph showing the number of deaths among residents shows the average over 7 days.

View the description of the 'averages over the past seven days' below

Changes in the figures
For reports of confirmed cases amongst residents without a stated first day of illness, the RIVM determines a calculated first day of illness. This calculation method has been adjusted from 16 July 2021. The figures for the number of infected locations have been retroactively adjusted on the dashboard.

Where do these figures come from?
The figures on people over 70 living at home are provided by the National Institute for Public Health and the Environment (RIVM). RIVM supplies the figures as an open data file.

How are these figures determined?
For its calculations RIVM uses the test results and mortality data that it receives from the municipal health service (GGD). When someone newly tests positive for coronavirus, the GGD records a number of details, including the person’s age and if they live in a nursing home or disability care home. RIVM calculates the number of new cases among over 70s living at home by first determining the total number of new cases in this age group and then subtracting the number of infections among:

nursing home residents
health workers
people who can be linked to a nursing home or a location for disability care on the basis of their postcode
people who can be linked to a nursing home or a residence for disability care on the basis of the location where the infection occurred.

We show the number of deaths among over 70s by the date of death. If we do not know the date of death, which is sometimes the case, we do not show the death on the dashboard.

Number of confirmed cases among the over 70s per 100,000
In order to compare groups of people with one another, we convert some figures to figures per 100,000 people. Likewise for the over 70s living at home. Statistics Netherlands collect data on the number of persons aged 70 and older who live at home (cbs.nl: 'StatLine - Huishoudens; personen naar geslacht, leeftijd en regio, 1 januari' in Dutch only). In the Netherlands, this group comprises around 2.3 million people.

See StatLine’s data on households in the Netherlands

National figures
Sometimes the data provided cannot be linked to a specific safety region. This means that the numbers at national level may sometimes be higher than the total of the numbers at safety region level.

Average over 7 days
The graph showing the number of confirmed cases among people over 70 living at home and the graph showing the number of deaths of people aged over 70 shows the average over 7 days.

View the description of the 'averages over the past seven days' below

Early indicators

Where do these figures come from?
The figures for wastewater testing are supplied by the National Institute for Public Health and the Environment (RIVM) as open data.

How are the figures determined?
Wastewater samples are collected at wastewater treatment plants across the country, so that data is available for all of the Netherlands. The samples of untreated wastewater are kept chilled during transport to RIVM. RIVM researchers analyse the samples and determine how many coronavirus particles each sample contains. At least once a week for each location, researchers test one sample of wastewater collected over a 24-hour period. The number of samples that can be analysed successfully differs from one week to the next. The open data file shows the date and location of successful measurements.

If the number of virus particles in a sample is too low to be measured, the value is recorded as 0.

See RIVM's explanation of sewage water testing

Assisted by the water authorities, Statistics Netherlands (CBS) has calculated the number of inhabitants served by each wastewater treatment plant, so that RIVM can determine the number of virus particles per 100,000 inhabitants.

See the explanation of the method for calculating the average number of virus particles in wastewater

Alert values under development
The values with different shades of blue are alert values under development. These values provide information on the severity of the situation. RIVM has based the values on the second wave of the coronapandemic. To this end, RIVM compared the values from the sewage measurements with the numbers of positive tests and hospital admissions. Values for positive tests and hospital admissions had been determined earlier to reflect the severity of the situation.

The values for the sewage measurements can still change. RIVM is investigating whether the current values can also be used when vaccination coverage is increasing, or whether adjustments are still needed. Once the values have been definitively established, they may play a role as an alert value to determine how serious the situation is in a region, in addition to data on positive tests and hospital admissions.

Changes in the figures
A measurement of 26 August 2021 from sampling location Dinther with a very high result, was published on the dashboard on 31 August 2021. This measurement also caused a large increase in the national figures. Because the value was so extreme and RIVM, after quality checks and research, has not yet found an explanation, RIVM has removed the measurement from the data on 1 September 2021. RIVM has conducted further research into other measurements from the same period. The results of samples taken on 25 August 2021 and on 30 August 2021 are now available on the dashboard.

From 4 March 2021 the dashboard also shows wastewater monitoring results for municipalities that do not have their own wastewater treatment plant. This is possible by using the measurements from all wastewater treatment plants that serve a municipality. Other figures were adjusted at the same time. To find out how the figures are calculated, see ‘How are the figures determined?’.

In 2020 two sampling locations were ended. Sampling for their catchment areas was taken over by two other locations. In the week of 5 October, the location at Aalst was taken over by Zaltbommel, and in the week of 7 December, the location at Lienden was taken over by Tiel. So the figures calculated for the locations at Zaltbommel and Tiel before that time are based on a lower number of inhabitants. You can find these numbers, as well as those of Aalst and Lienden, in a table compiled in 2020 by Statistics Netherlands (CBS).

Behaviour

Where do these figures come from?
Once every three weeks the National Institute for Public Health and the Environment (RIVM) delivers the results of a behavioural survey. This data is available in the form of an open data file.

How are these figures determined?
Every three weeks the RIVM conducts a survey to determine the extent to which people comply with and support the coronavirus measures. Around 5,000 people aged 16 and over participate in this survey.

See the RIVM's explanation of the survey

Changes in the figures
Since the 12th round of the survey, which was conducted from 11 to 17 May 2021, the RIVM has amended the questions about two rules.

Curfew
The curfew was lifted on 28 April 2021. Accordingly, RIVM no longer measures compliance with and support for this rule. On the dashboard we show the figures relating to the curfew up to 26 April.

Stay at home if you have symptoms
Up to and including the 11th round of the survey, RIVM may have incorrectly included some people in the group that ignored the basic rule of staying at home if they had symptoms. These were people who had symptoms suggestive of COVID-19 and who did leave their homes, but only after they had tested negative. In other cases, people may have had an urgent medical reason for leaving their homes without first testing negative. While these individuals may not have stayed at home, they did in fact correctly observe the rule. RIVM has therefore rephrased the question relating to this rule.

Because RIVM has rephrased the question, we only show the data based on the new question on the dashboard. The older data is still available in the RIVM’S open data file.

Work from home if possible
The rule ‘work from home if possible’ was not measured in the 14th round (29 June - 5 July) and the 15th round of the survey (13-19 July), because the measure was temporarily abolished. The rule has been measured again from 16th round of the survey (3-9 August).

Other

Where do these figures come from?
The data for the CoronaMelder app come from the Ministry of Health, Welfare and Sport. This data is available as open data.

See the open data set for the CoronaMelder app

How are these figures determined?
Alerts for infection
The dashboard shows how many CoronaMelder users who tested positive alerted other app users that they may be infected. This figure, taken from the GGD portal, is based on the number of codes shared each day.

Number of downloads
We also show how many people have downloaded the CoronaMelder app. This figure is calculated by adding together the daily statistics for downloads via:

Google Play Store (Android)
App Store Connect (iOS)
AppGallery Connect (Huawei)

Where do the figures come from?
Confirmed cases
The National Institute for Public Health and the Environment (RIVM) supplies the figures as open data.

Hospital and ICU admissions
RIVM supplies these figures as open data. For each age group, the graph shows the total number of admissions per week (source NICE, processed by RIVM).

Deaths
The graph showing age distribution at national level is based on a RIVM open data file.

Age distribution of the Dutch population
Figures on the age distribution of the population come from open data from Statistics Netherlands (CBS).

See the CBS data on population distribution

How are these figures arrived at?
Confirmed cases
The figures in the graph showing positive tests per age group come from a different data source than the figures on confirmed cases. because there are no ages in the dataset on positive tests. Different dates are used in the two datasets.

The dates used in the age distribution data set are:

the first day of illness
if this is unknown, then the date of the first positive laboratory test result
if this date is also unknown, the date on which the municipal health services (GGD) were notified of the positive result.

The data set uses the date reported by RIVM. This date is usually later than the actual date of the positive test result. This explains why there are differences between the graph that shows the total number of confirmed cases and the graph that shows positive cases per age group. The figures in the age distribution graph are seven-day rolling averages. In addition, sometimes the age of someone who tests positive is unknown.

The graph showing the age distribution of positive tests gives averages over the preceding 7 days. In order to be able to compare age groups, we calculate numbers per 100,000 people.

Hospital and ICU admissions
The data contains the weekly totals of the admissions that took place in that week per age group (source NICE Foundation, edited by RIVM). The graphs for hospital and ICU admissions show these weekly totals. To be able to compare age groups, we calculate numbers per 1,000,000 people from a specific age group. We determine the population size per age group on the basis of the CBS classification.

Deaths
Distribution according to age Everyone under the age of 50 is placed in the same age group, as the low numbers of deaths in this age group, in combination with the breakdown of COVID-19 deaths elsewhere on the dashboard, would otherwise enable tracing of the data to individuals.

Example
On 1 October 2020, the 7-day average of the number of positive tests in people aged 90 and older was 26.14. There are a total of 129,831 people aged 90 and older in the Netherlands. So the number of positive tests per 100,000 in the 90 and older age group is 100,000 / 129,831 * 26.14 = 20.13.

Calculating this for each age group and depicting the figures in one graph creates a clear picture of each age group, and allows us to compare the groups with one another.

The national average shown in the age graph is the average of all those cases whose age is known. For example, comparing the 90+ age group with the national average, the national average is made up of all age groups, including the 90+ group.

In the age distribution graph, the data from the last few days is not yet complete. RIVM supplements the data retrospectively and may also make corrections.

Where do the numbers come from?
The population numbers per municipality come from the national office Statistics Netherlands (CBS), reference date 1 January 2021.

• View the figures from Statistics Netherlands (CBS) on the population numbers

How are these figures arrived at?
To be able to compare municipalities, we convert some figures into figures per 100,000 people. We do this so we can compare larger municipalities and smaller municipalities. If we did not do that, municipalities such as Amsterdam and Rotterdam would always have high figures, because many more people live there compared to smaller municipalities.

Example:
In Katwijk, a total of 47 people had a positive test result on 3 May 2021.
According to figures from Statistics Netherlands, 65,995 people live in Katwijk.
The calculation we make is 47 / 65,995 * 100,000 ≈ 71.2.
On 3 May, 71.2 people per 100,000 people had a positive test result in Katwijk.

In Amsterdam, a total of 455 people had a positive test result on 3 May 2021.
According to figures from Statistics Netherlands, 873,338 people live in Amsterdam.
We make the same calculation: 455 / 873,338 * 100,000 = 52.1.
So, 52.1 people per 100,000 people in Amsterdam had a positive test result on 3 May.

Amsterdam has more inhabitants than Katwijk, but by converting to positive test results per 100,000 people, we can compare the two municipalities. On May 3, 2021, more people per 100,000 inhabitants had had a positive test result in Katwijk that day than in Amsterdam.

Because the number per 100,000 people is a calculation, it is possible the number has a decimal point.

Where do the numbers come from?
The population numbers per municipality come from the national office Statistics Netherlands (CBS), reference date 1 January 2021.

• View the figures from Statistics Netherlands (CBS) on the population numbers

How are these figures arrived at?
To find out what the situation is like in a safety region, we look at how many people from a safety region were admitted to hospital in the past 7 days per 1 million inhabitants. We do this so we can better compare large and small safety regions with one another. If we didn’t do this, densely populated safety regions such as the safety region Utrecht would have higher figures, because more people live there than in less densely populated safety regions.

Example:
In the safety region Groningen, a total of 38 people were hospitalized in the period from 3 to 9 May 2021.
According to figures from the CBS, there were 586,937 people living in the safety region Groningen on that date.
The calculation we then make is 38 / 586,937 * 1.000,000 ≈ 64.7.
So on from 3 to 9 May, a total of 64.7 people per 1.000,000 inhabitants were hospitalized in the safety region Groningen.

In the safety region Utrecht, a total of 71 people were hospitalized in the period from 3 to 9 May 2021.
According to figures from the CBS, there were 1.361,153 people living in the safety region Utrecht on that date.
The calculation we then make is 71 / 1.361,153 * 1.000,000 = 52.1.
So on from 3 to 9 May, a total of 52.1 people per 1.000,000 inhabitants were hospitalized in the safety region Utrecht.

More people live in the safety region Utrecht than in the safety region Groningen, but by calculating the hospitalizing’s per 1.000,000 people we are able to compare the two safety regions. From 3 to 9 May 2021 more people per 1.000.000 inhabitants in the safety Groningen were admitted to hospital than in the safety region Utrecht.

Because the number per 1.000,000 people is a calculated rate and therefore does not express an exact number of people, it can be rounded off to the nearest tenth (one decimal place).

In various graphs on the dashboard, in addition to the figures per day, we also show seven-day rolling averages. The graphs based on daily figures fluctuate more strongly with the day-to-day differences. By adding up all figures over the last seven days and dividing them by seven, an average of the past seven days is created. Together, these averages (the rolling average) give a clear picture of the trend.

Example
On Monday 10 May, the average over the past seven days was the average of 4 to 10 May, inclusive. We added up all the figures for those days and divided the total by seven. On Tuesday 11 May we did the same, but over the days from 5 to 11 May, inclusive. This means that every day we get a new average over the past seven days, and we are able to examine the trend closely.

On the dashboard we use ‘value of’ to indicate the date to which the figures refer, while ‘obtained on’ is used to refer to the date on which we received the data. This clearly shows how up-to-date the data is, in particular for indicators that look back over time.

An example of a subject where ‘obtained on’ tells us more about how current the data is than ‘value of’ is the reproduction number (R). RIVM publishes this number twice a week, but the R is always for a date two weeks in the past.

'value of’ indicates a date two weeks ago
‘obtained on’ indicates the date on which RIVM published the most up-to-date value of R.

So, for example, this will appear on the dashboard: ‘Value for Thursday 13 May obtained on Friday 28 May’.

On 1 January 2021 a number of municipalities were merged, forming new municipalities. As of 7 January, RIVM has processed the data it provides for the Coronavirus Dashboard in accordance with these new municipal boundaries. We have modified the municipal and safety region maps on the dashboard to reflect the boundary changes. We have added the 2020 figures from municipalities that no longer exist to the figures of the municipalities that they have been merged with.

Changes in the figures
Some of the figures on the Dashboard are calculations per 100,000 or 1 million people. We present them in this way so it is possible to compare municipalities or safety regions with different populations. All 2020 figures are based on population data from the national office Statistics Netherlands (CBS), using 1 January 2020 as reference date.

The 2021 figures are based on population data from Statistics Netherlands using 1 January 2021 as reference date. Until 17 August 2021, however, the figures from 1 January to 17 August calculated per 100,000 or 1 million people had been based on CBS population data from 1 January 2020. As of 17 August all 2021 figures are now based on the new data from Statistics Netherlands using 1 January 2021 as reference date. The figures on the Dashboard from 1 January 2021 onwards were retroactively updated on 17 August. The corrected figures may be slightly higher or lower, depending on the population data of the municipality or safety region in question. Any differences are minor.

Archived

Where did these figures come from?
Until 9 July the National Institute for Public Health and the Environment (RIVM) supplied data on the number of infectious people twice a week. This data is available as open data.

How are the figures determined?
Someone who is infected with coronavirus can transmit the virus to other people. How long they are infectious for differs from one person to another. The precise number of infectious people is unknown, but RIVM calculates the range within which this number probably lies using data from the Pienter Corona study and the number of hospital admissions.

Changes in the figures
From 1 June 2020 until 12 October 2020 the number of infected people was estimated on the basis of data from the first round of the Pienter Corona study, the number of hospital admissions and the number of confirmed cases. As of 13 October 2020, this figure is estimated using data from the second round of the Pienter Corona study and the number of hospital admissions. In the second round of this study, a larger group of people was tested to find out if they were infected with coronavirus, and more insight was gained into the degree of people’s infectiousness.

From 9 July 2021, RIVM will no longer calculate the number of infectious people for the time being. This figure is based on the number of hospital admissions. More and more people have been vaccinated and fewer people are hospitalized as a result. The difference between the number of infections among people and the number of hospital admissions is increasing. Therefore, the number of infectious people is no longer calculated.

Where do these figures come from?
Until 1 Sepember 2021, the Netherlands Institute for Health Services Research (NIVEL) reported on thursday of each week, the figures from general practitioners on patients with COVID-19-like symptoms. This data is available in the form of an open data file.

How were these figures determined?
Once a week, a representative sample of around 350 GP practices across the Netherlands provided data concerning the symptoms of patients they have seen to NIVEL’s Primary Care Database. Using this data, NIVEL determined the number of patients who have reported COVID-19-like symptoms in the past week. NIVEL determined this on the basis of the diagnostic codes reported by GPs and any additional information provided that is suggestive of COVID-19. These diagnostic codes are:

acute infection of the upper airways
other infections of the airways
influenza
pneumonia
other viral disease
other infectious disease
fever
shortness of breath
cough

In order to achieve greater accuracy, each week NIVEL also recalculated the data from the preceding weeks. It also included data that was only published at a later date.