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 a set of access standards, including the average waiting time in A&E, time to initial clinical assessment, and time to emergency treatment for critically ill and injured patients. 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. However, NHS England has confirmed that the A&E performance standards being trialled will be rolled out. 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.
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 Q1 2020/21 (April to June 2020), waiting time performance improved sharply to 90%. However, this corresponds to a considerable decrease in the number of A&E attendances during the coronavirus (Covid-19) outbreak.
The total number of A&E attendances had been increasing over time, reaching over 6.5 million attendances in Q2 2019/20 (July to September 2019). In Q1 2020/21, the total number of A&E attendances fell dramatically to 3.6 million – 44% lower than in Q1 2019/20. This reflects changes in access and service use during the Covid-19 outbreak and lockdown period.
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. In 2019/20, there was a substantial drop in performance, falling to an all-time low of 69% in December 2019. By June 2020, performance had increased to 90%, however this came alongside a substantial fall in A&E attendances, with 24% fewer type 1 A&E attendances in June 2020 than in June 2019.
As well as looking at the proportion of patients attending A&E who are admitted, transferred or discharged within four hours, we can also study the median number of minutes spent in A&E. The median waiting time for all patients increased from 129 minutes in May 2011 to 174 minutes in December 2019, before falling to 135 minutes in May 2020 during the Covid-19 outbreak.
For patients who required admission to hospital, the median A&E waiting time remained below four hours until September 2019. Note that the four-hour A&E target is for 95% of patients to be seen in four hours, while the median represents 50% of patients. In December 2019, the median wait increased dramatically to 321 minutes. This may reflect the increase in trolley waits (the time patients wait from when a decision is made to admit and them being admitted) in the winter of 2019. But it is also worth noting that these data are provisional and sensitive to poor data quality (see ‘About this data’ for more information). In May 2020, the median waiting time for admitted patients fell to 213 minutes.
The median waiting time for non-admitted patients was 97 minutes lower in May 2020, at 116 minutes.
Median waits are routinely published by NHS Digital each month, but the new A&E standards will measure the mean time in A&E (not currently published).
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 changed little between May 2011 and February 2020, ranging from a low of 46 minutes in January 2015 to a high of 70 minutes in November 2019. In April 2020, the median treatment waiting time fell to 24 minutes, following the decrease in A&E attendances during the Covid-19 outbreak.
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 a high of 277 minutes in December 2019. In April 2020, the 95th percentile value fell dramatically to 121 minutes, before increasing slightly in May to 138 minutes. 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).
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. In the winter of 2019, there was a considerable increase in the number of patients waiting over four hours and over 12 hours between the decision to admit and admission. In December 2019, 98,452 patients waited over four hours and 2,347 patients waited over 12 hours. This compares to 59,805 patients waiting over four hours and 284 waiting over 12 hours in December 2018.
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 the 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 June 2020, along with the fall in A&E attendances, 4.1% 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 time 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 2019, 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 its 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:
Median waiting time in A&E and time to treatment are 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.