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 four new measures. NHS England has selected 14 hospital trusts to field test the new standards, and there is indication that they could be implemented across the country in October 2019. The existing four-hour target remains in force until new clinical 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 2008. 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 percentage of patients attending A&E that were admitted, transferred or discharged within four hours rose dramatically with the introduction of the 98% target in January 2004, and this target was met in Q2 2005/06. Over the next five years, performance varied between 96% and 98%, and while there were large increases in the number of people using minor A&Es, increases in major A&E attendances were modest.
The relaxation of the target to 95% in 2010 was associated with an increase in patients waiting more than four hours in major A&Es, but performance initially remained close to or above the new target. By Q4 2017/18, performance had fallen dramatically to 76.8%, the worst level since the introduction of the four-hour target. In Q4 2018/19, performance was only marginally better at 77.2%. Meanwhile, the total number of A&E attendances has been increasing over time, reaching over 6.2 million attendances in Q4 2018/19.
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 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. Unlike most winters, there was no recovery in February or March 2018, leading to a particularly poor start to 2018/19. By February 2019, performance had fallen to an all-time low of 75.7%, recovering slightly to 79.5% in March.
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 134 minutes in February 2012 to 165 minutes in February 2019.
For patients who required admission to hospital, the median A&E waiting time was 239 minutes in February 2019. This is just one minute shorter than the four-hour target, meaning that about half of admitted patients waited longer than four hours. The median waiting time for non-admitted patients was significantly lower at 146 minutes.
Median waits are routinely published by NHS England each month, but the Review of NHS Access Standards is proposing to measure the mean time in A&E as a new standard. For more information on what the proposed A&E waiting time targets will mean for patients, read the latest Nuffield Trust blog.
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 69 minutes in March 2016.
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 fluctuated at a higher level of about 213 minutes. A peak of 243 minutes was reached in February 2019. It's worth noting that this measure can be sensitive to data quality issues.
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. However, the peak in January 2019 (14.8%) was slightly lower than it was in January 2018 (15.4%) and January 2017 (16.2%), indicating that there may have been a small improvement over the last two years. In March 2019, 10.7% of patients breached the four-hour target.
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 2018 at 1,054. 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. Promisingly though, in the most recent winter the peak in January had decreased by 42% compared to the previous year.
About this data
In January 2019, 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. For more information, see the most recent HSJ article.