# Long A&E waits by London trust

> Four-hour attendance waits and 12-hour waits after a decision to admit, with their different denominators kept explicit.

- Category: NHS
- Cadence: monthly
- Status: Published on a monthly cadence.
- Dataset key: `nhs-ae-waits-by-trust`
- Source: [NHS England](https://www.england.nhs.uk/statistics/statistical-work-areas/ae-waiting-times-and-activity/)
- Licence: Open Government Licence v3.0 — [terms](https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/)
- Canonical page: [https://londongraph.com/g/nhs-ae-waits-by-trust](https://londongraph.com/g/nhs-ae-waits-by-trust)
- Machine-readable record: [https://londongraph.com/data/nhs-ae-waits-by-trust](https://londongraph.com/data/nhs-ae-waits-by-trust)

## Methodology

Latest Monthly A&E Attendances and Emergency Admissions provider CSV, filtered to active London trusts through NHS ODS. Four-hour waits are divided by total A&E attendances; 12-hour decision-to-admit waits are divided by emergency admissions via A&E. The two rates have different denominators, answer different questions and describe providers, not residents of their host boroughs.

## Visualisations

- [Overview](https://londongraph.com/g/nhs-ae-waits-by-trust): Four-hour attendance waits and 12-hour waits after a decision to admit, with their different denominators kept explicit.
- [Distribution](https://londongraph.com/g/nhs-ae-waits-by-trust?view=distribution): Show every published value around the median and quartiles.
- [Four vs twelve hours](https://londongraph.com/g/nhs-ae-waits-by-trust?view=relationship): Compare the two A&E waiting measures without mixing their denominators. Caveat: A spatial association does not establish that either measure causes the other.

## Citation guidance

Attribute the original publisher named above and identify LondonGraph as the visualisation and methodology layer. Do not describe live values as a historical census, and do not present placeholder values as observations.