How Age Flags works

Sources

Recommendations come only from government health agencies and statutory committees in the United States, England, China, Japan, Spain and Brazil. Each item links to the page or document it comes from and shows the date it was last checked. The year shown with each guideline is the date of the source document when Age Flags added it; if a figure later changes on the source page, the item also shows the date of that update and the updates page records it.

How numbers are handled

Every age, interval and dose timing on the site is stored as a structured value next to a short passage copied from the source. Software checks every day that the passage is still on the government page and that each number appears in it next to its unit. Translations never change numbers: they are inserted from the stored values.

When a guideline changes

If a source page changes, the new version is read again and compared field by field with what the site shows. A changed age, interval or threshold in a screening or vaccination item is published only after it has been stable for at least three days and a second, independent government source says the same. Until then the old figure is withdrawn and replaced by a link to the source.

What is not updated automatically

New screening or vaccination programmes are added only when the site itself is updated; the updates page covers changes to items already listed. When an agency lists a new edition of a dated document, such as a yearly schedule, that Age Flags has not yet checked, the old edition is still shown with a note, but its last checked date stops moving; if the new edition has not been added within three weeks, the affected items are temporarily withdrawn. Background facts about body changes, risks and lifestyle are never rewritten automatically: if their source no longer supports them, they are withdrawn, and their numbers change only when the site itself is updated and a second, independent government source gives the same figure.

Childhood vaccines

For childhood vaccines, the "who it is for" age range is the range the programme covers. Where the source lets anyone in that range who missed a dose still have it, the range includes that catch-up; the dose column gives the standard timing. In the checklist, earlier doses the programme still offers at the child's age are listed separately. A catch-up schedule can need fewer or different doses, so check the source.

Pregnancy

Recommendations that apply during pregnancy are not tied to an age range. They are listed in the pregnancy section of each country's full schedule, and the age pages for teenagers and adults under fifty link there.

Dates on each page

"Page content last changed" is the date on which the content of the page last changed. "Sources last checked" is the earliest date on which the sources behind the page were last confirmed.

Age ranges and sex

Pages cover age ranges from under one year to seventy-five and over. Tests listed by sex refer to organs present at birth.

Ancestry notes

Notes about ancestry or background appear only where a guideline mentions a difference. Ancestry is a population-level stand-in for risk factors, not a biological cause.

The checklist tool

The checklist only filters published guideline items by age, sex and country in your browser. It does not assess personal risk and nothing is sent anywhere.

AI disclosure

Pages are written and translated by AI and checked by software against their sources. No doctor or human editor reviews them.

Licences

Content from England contains public sector information licensed under the Open Government Licence v3.0. Material adapted from the US Preventive Services Task Force has not been reviewed or endorsed by AHRQ or HHS. Japanese material is based on content from the Ministry of Health, Labour and Welfare website, adapted by Age Flags. Content from Spain comes from the Ministry of Health (Ministerio de Sanidad); each item shows the year of the version Age Flags used and, if a figure later changed, the date of that update. Content from Brazil uses only facts from government pages, without reproducing their text. Population figures are from World Population Prospects 2024 (CC BY 3.0 IGO), calculated by Age Flags. The structure and wording of the Age Flags dataset are available under CC BY 4.0; the original guidelines remain the property of their publishers.