A&E waiting times

Analysing data on waiting times in A&E, we look at the commitment to a maximum four-hour wait.


Last updated: 01/05/2020

Access and waiting times
Emergency care


The four-hour A&E waiting time target is a pledge set out in the Handbook to the NHS Constitution. The operational standard is that at least 95% of patients attending A&E should be admitted, transferred or discharged within four hours.

In March 2019, the Review of NHS Access Standards was published, which proposed that the current four-hour A&E target should be replaced by an average wait measure of the mean time spent across all patients in each A&E department. NHS England selected 14 hospital trusts to field test the new standards, and an interim report was published in October 2019. Due to the coronavirus (Covid-19) outbreak, publication of the review’s recommendations has been delayed until late 2020. The existing four-hour target remains in force until any new standards are announced. Read the latest Nuffield Trust blog for more information about what the proposed A&E targets could mean for patients.

This indicator explores breaches of the four-hour A&E target since 2010. For in-depth analysis of what's causing increasing A&E waits, see our report Focus on: A&E attendances.

See also our Combined Performance Summaries, which present up-to-date information on key NHS performance measures as data are released by NHS England.

How has performance against the four-hour A&E target changed over time? 01/05/2020

Chart QualityWatch

Read more

The length of time patients spend in A&E depends on the type of A&E unit they visit. Minor A&Es (types 2 and 3, such as single specialty departments or minor injury units) nearly always treat people in less than four hours, but major A&Es (type 1) deal with a higher number of attendees and more serious cases, meaning they find it harder to achieve the four-hour target.

The target for the percentage of patients attending A&E that are admitted, transferred or discharged within four hours was relaxed from 98% to 95% in 2010. Performance initially remained close to or above the new target. By Q3 2019/20 (October to December 2019), performance had fallen dramatically to 72%, the worst level since the introduction of the four-hour target. In Q4 2019/20 (January to March 2020), performance was only marginally better at 73%.

Meanwhile, the total number of A&E attendances had been increasing over time, reaching over 6.5 million attendances in Q2 2019/20. In Q4 2019/20, the total number of A&E attendances fell by 14% on the previous quarter to 5.6 million, which reflects changes in access and service use with the onset of the coronavirus (Covid-19) outbreak.

How strongly do seasons influence breaches of the four-hour A&E target? 01/05/2020

Chart QualityWatch

Read more

The impact of winter pressures on performance against the four-hour A&E target is apparent. There is a general trend for performance to be higher in the summer, despite the fact that A&E sees the highest numbers of attendees at this time. This is explained by changes in the case-mix of people attending. In summer, A&Es see a higher proportion of cuts and sprains, most of which can be treated relatively quickly. In winter, there is a larger proportion of older people attending and a greater number of people requiring emergency admission to hospital.

Drops in performance are normally observed from November in any given financial year. Performance generally recovers at least partially by April the following year.

On the whole, there has been a year-on-year decrease in the proportion of patients attending major A&E departments that are admitted, transferred or discharged within four hours and over the last year there has been a substantial drop in performance. Between 2018/19 and 2019/20, there was an average decrease in performance of 6 percentage points per month. In December 2019, performance fell to an all-time low of 69%, recovering slightly to 76% in March 2020.

How long do people wait for treatment to begin? 01/05/2020

Chart QualityWatch

Read more

While adherence to the four-hour target is the iconic measure of A&E performance, the length of time between patients arriving in A&E and their treatment beginning is another important indicator. This chart shows that the median treatment waiting time has changed little since 2011, ranging from a low of 46 minutes in January 2015 to a high of 70 minutes in November 2019.

Interestingly, the 95th percentile value – that is, waiting times for some of the patients that wait the longest – fluctuated at around 185 minutes until August 2015, before increasing to 223 minutes in March 2016. Since then, the 95th percentile value has increased, reaching a high of 277 minutes in December 2019. It’s worth noting that this measure can be sensitive to data quality issues.

The Review of NHS Access Standards intends to measure the time to emergency treatment for critically ill and injured patients. It proposes introducing a package of treatment to be completed in the first hour after arrival for life-threatening conditions such as stroke, heart attack, major trauma, asthma and acute physiological deterioration (including sepsis).

Trolley waits: how long do people wait to be admitted onto a hospital ward? 01/05/2020

Chart QualityWatch

Read more

For patients that require admission to a hospital ward, the time they wait between the A&E unit deciding that they should be admitted and the patient actually arriving on the ward is very important. The line on this chart shows that the percentage of admitted patients waiting over four hours between the decision to admit and admission is highest in winter months and has increased substantially since 2010. The peak in January 2020 (18%) was higher than in January 2019 (14.8%) and January 2018 (15.4%). In March 2020, 12.1% of patients waited over four hours from a decision to admit to admission.

The bars on the chart show the number of people waiting over 12 hours to arrive on a ward. The number of extreme waits peaked in January 2020 at 2,846. While this is very small in comparison to the total number of people attending A&E departments, the number of patients waiting an extremely long time to be admitted onto a ward has grown substantially since 2010.

About this data

NHS England data:

In March 2019, the Clinically-Led Review of NHS Access Standards Interim Report was released, proposing some significant changes to A&E waiting times targets. A six-month Progress Report from the NHS Medical Director was also published in October 2019.

Field testing of the proposed new standards began in 14 hospital trusts on 22 May 2019. The first stage of testing focused on measuring the “mean time in A&E”, when compared to the existing four-hour target. The field test sites have not been submitting four-hour performance data since May, so an adjusted national time series was published to omit these sites’ A&E performance going back to Q1 2011/12. The time series data presented here for performance against the four-hour target excludes the field testing sites and so is comparable across months and years. Data on A&E attendances is for all trusts, including the field testing sites.

In January 2018, the NHS Improvement chief executive Ian Dalton wrote to trusts to announce a formal review of the reporting of A&E performance data. The letter refers to issues in two main areas: the reporting of urgent care (type 3) activity, and the reporting of activity from newer clinical pathways, such as ambulatory care services.

It followed the UK Statistics Authority writing to NHS England to formally raise concerns about the impact of changes to recording practice and the interpretation that should be applied. This prompted questions of whether the data was reliably measuring pressure and performance over winter.

In November 2018, the UK Statistics Authority stated that their concerns had been addressed, however, some concerns still remain about the quality of performance data. For more information, see the most recent HSJ article.

NHS Digital data:

Time to treatment is calculated using provisional A&E Hospital Episode Statistics (HES) data. Provisional HES data may be revised throughout the year. As these indicators are published on a monthly basis rather than in a time series, indicator data published for earlier months have not been revised using updated HES data extracted in subsequent months.

NHS Digital notes that several organisations report data that does not meet the data quality checks required by A&E indicators, which contributes to why unusually high values may be observed for some measures.