Why are people waiting longer in A&E?

Report author Ian Blunt explains how we used de-identified patient-level data to track millions of people's journeys through the health service.

Blog post

Published: 25/07/2014

Very few people would doubt that Accident and Emergency departments are under huge pressure at the moment. Several reports have documented the stresses and strains in the system, and this week marks one full year since England's major A&E departments last met their target of 95% of patients waiting less than four hours from arrival to departure. 

There is no shortage of commentators offering explanations on why this is happening. It’s an aging society; it’s alcohol; it’s long-term conditions; it’s too few doctors. But as the Commons Health Select Committee pointed out, the NHS simply does not have the information it needs to fully understand what's going on in A&E.  This means we’re left debating people’s alternative opinions. These are perfectly valid – often informed by frontline experience – but we need evidence to move the debate forward. 

An evidence-based approach

We looked at data from 41 million episodes of people turning up at A&E and tracked what happened to them.

This report from our QualityWatch programme set out to explore the main factors thought to be causing the pressure on A&E using a slightly different approach. We used de-identified patient-level data, which lets us track huge numbers of real people through the health service but without disclosing their identities. It is a very powerful tool for understanding how health services operate, especially when those data can be linked together across settings and over time. So we looked at data from 41 million episodes of people turning up at A&E and tracked what happened to them. 

We found that:

  • Most of the recent increases in attendances have been in minor A&E units (such as urgent care centres or minor injury units).  The number of people using major A&E departments has increased, but only by as much as would be expected from population growth and ageing.
  • Increases in the number of older people using A&E accounted for around one tenth of the decline in performance against the four-hour target
  • The unusually cold winter in 2012/13 accounted for a fifth of the performance drop in the winter months.
  • Inpatient bed availability played a part in meeting the four-hour target, but it was difficult to quantify exactly how much.  
  • Patient satisfaction with access to their GP was not associated with breaches of the four hour target – although it did have some effect on the number of people who turned up in the first place.
  • It was possible to estimate how “crowded” an A&E department was – that is, the number of people in a department at any one time. This number had increased by 8% between 2010 and 2013.
  • Higher levels of A&E crowding (relative to what you'd expect for that time of the week) were strongly associated with breaches of the target, but a quarter of breaches occurred when departments were less crowded than would be expected.

Our analysis was able to suggest how much of the pressure was due to ageing and winter, but these factors did not explain all of the decline in performance, as measured by the four-hour target.  It might be that existing A&E facilities are  reaching the limit of what can be achieved, which could well lead us to a tipping point where even small further increases in demand can result in a disproportionate increase in breaches.  

More data needed

Better data would allow us to properly assess the influence of bed availability and staffing levels.  Staffing is clearly an important issue but we must be cautious about accepting it just because it’s the only explanation left.  It has been suggested that some hospitals engineer their patient flow so that waits cluster just before four hours, which would also produce the effect that small additional demand results in dramatic increases in breaches.

Various ways to reduce the pressure in A&E have been proposed, either by reducing attendances or increasing capacity.  What is clear is that, with NHS resources being extremely limited, understanding the relative influence of the causes of the pressure on A&E is more important than ever. Without the evidence we need to target improvements, we run the risk of carrying on the same old debates while ill or injured patients wait longer and longer.