A&E: A Tale of Two Winters

During PMQs on 14th May the Prime Minister stated:

“[The Leader of the Opposition] predicted a winter crisis, and he sat there day after day, dying for it to happen. It did not happen because we have a strong NHS with more doctors and more nurses serving our country.”

Is it correct to say that the winter crisis “did not happen”? How did Accident and Emergency departments in England fare over the winter of 2013-14? The short answer is: it depends. Specifically, it depends on what you’re comparing it to.

Waiting Times

During the period from October 2013 to April 2014 (inclusive), 7% of attendees at major A&E departments in England waited for over four hours for discharge, admission or transfer. This is above the target of 5%, and above the overall 2013/14 figure of 6.2%. Furthermore, this comes despite the fact that the winter period was the quietest time in the year for most A&E departments. So in one respect, this performance looks mediocre at best, and certainly nothing to write home about. (See this previous post, however, which explains why winter puts pressure on A&E departments).

However, things look rather different if we compare this winter with the previous winter. The following chart shows equivalent trends for winters 2012/13 and 2013/14:

Paients Waiting over four hours at A&E
Source: Weekly A&E Sitreps

During the period from October to February, the two winters were broadly similar, with 7.2% of patients waiting over four hours in 2012/13 compared with 7.1% in 2013/14. However, from March onwards, 2013/14 marks a huge improvement on 2012/13. During March and April 2013, 10.0% of patients waited for over four hours, compared with 6.8% in March and April 2014. So in this respect, it is correct to say that the ‘crisis’ of March and April 2013 was not repeated this year.

This pattern was especially evident in certain parts of the country. The most improved NHS trust over the periods in question was University Hospitals Coventry and Warwickshire NHS Trust, which reduced its proportion of patients waiting over four hours from 18.0% to 5.2%. Burton Hospitals NHS Trust and Weston Area Health NHS Trust were the other two most-improved trusts.

However, in other areas of the country the opposite trend was visible – the performance of some trusts declined on 2012/13. King’s College Hospital NHS Trust slipped from 5.2% waiting over four hours in 2012/13 to 15.9% in 2013/14 – ostensibly because of its acquisition of the struggling Princess Royal Hospital in Bromley as a consequence of the dissolution of South London NHS Trust. The Royal Cornwall Hospitals NHS Trust also saw a decline in performance from 8.0% in 2012/13 to 12.5% in 2013/14. Mid Staffordshire NHS Foundation Trust and Blackpool Teaching Hospitals NHS Foundation Trust were among other trusts experiencing a decline in performance.

Winter Pressures

Another important measure of A&E performance is the ‘Winter Pressures’ data series, which show a somewhat mixed picture. This data is available from November to February (inclusive) for 2012/13 so comparisons here are to the equivalent period in 2013/14.

The number of ambulance handovers delayed for over 30 minutes was significantly lower in every week of 2013/14 compared to 2012/13. The total number of delays was 30% lower in 2013/14. In both years there was a statistically significant positive correlation between the number of ambulance delays in any given week and the percent of patients waiting for over four hours in A&E in that week.

Ambulance Handover Delays

Other measures also show improvement: for instance, the number of bed days lost to Norovirus was 52% lower in 2013/14 than in 2012/13.

Bad days lost to Norovirus

Not all measures show this improving trend, however. For instance, there were more than double the number of trolley waits of over 12 hours in 2013/14 than 2012/13, at 129 – though it should be noted that 52% of all of these waits were due to a single NHS trust (King’s College), so this does not reflect a national trend.

Comparing Apples and Oranges?

A key issue in this debate is whether the improved performance in 2013/14 can really be attributed to factors internal to the NHS – i.e. a “strong NHS” and “more doctors and more nurses”, as the Prime Minister claimed – or instead is dependent on external factors.

One such external factor is that most British of concerns: the weather. 2013/14 was a mild wet winter, with temperatures “well above the long-term average for all three months” (Met Office). By contrast, temperatures in 2012/13 were slightly below the long-term average.

Another (perhaps related) factor is the incidence of diseases like influenza. According to data from the HPA, incidence of influenza was lower in winter 2013/14 than in the equivalent period for 2012/13. This may have had an alleviating impact on A&E pressures.

While inconclusive, these factors serve as a reminder that we cannot necessarily attribute improvements in A&E performance indicators to factors directly under the control of either the NHS or the government.

Author: Carl Baker