Chief Statistician’s update: comparing NHS performance statistics across the UK

Darllenwch y dudalen hon yn Gymraeg

The provision of health services is devolved across the four nations of the UK. As a result, the way we measure NHS activity and performance in each nation differs, in order to reflect the different policy priorities and circumstances of each nation. While there are similarities in the types of data collected, there are also important differences in coverage and definitions, meaning that the headline statistics are often not directly comparable. However, understandably, there is considerable interest in making these comparisons, so this blog post aims to offer advice on doing this.

What impact has the pandemic had on the NHS?

There has been a great deal of interest in understanding how the pandemic has affected health services across the UK and the performance in addressing this. Consequently, it is not uncommon to see overt comparisons of the statistics for the four nations in media articles and public discourse, despite the important methodological differences. As there are differing measures in each nation, this isn’t always straight forward to do. One way to overcome this is to look at how much waiting lists increased in each nation during the pandemic. Although the detail of what’s included in each nation’s waiting list figures might vary, this approach gives us a broad indication of the relative change in demand on health services.

Using this method, we can see that generally the impact has been similar across Wales, England and Scotland with increases of 55-75% in recorded patients waiting for treatment. Data for Northern Ireland imply a smaller increase in waiting lists, though this may reflect GPs stopping referrals for certain complaints during the pandemic.

If we want to make more detailed comparisons, we need to understand in more depth about how measures differ in each nation and the impact this has on comparability. Otherwise, we risk not comparing like with like.

Across the nations data are available covering a wide range of NHS activity including treatment waiting lists, emergency care and cancer services. In this blog post we focus on waiting list statistics, known as referral to treatment (RTT) pathways in Wales.

What are the headline statistics for waiting lists produced by each nation?

Each UK nation publishes statistics on its NHS waiting lists on a monthly or quarterly basis.

In Wales, at the end of September 2022 there were around 755,000 recorded patient pathways currently waiting.

In England, at the end of September 2022 there were 7.1 million ‘incomplete RTT pathways’ (patients waiting to start treatment).

In Scotland and Northern Ireland, statistics are reported for patients waiting for a first outpatient appointment, a diagnostic service or treatment. Follow-up outpatient appointments are not reported, unlike in the data for England and Wales. In June 2022 there were around 748,000 such patients waiting in Scotland.

In Northern Ireland, there were around 672,000 recorded patients waiting in the outpatient, diagnostics and treatment categories in June 2022. However, this is known to include some duplication, meaning the true number would be lower.

In all cases these are counts of pathways or referrals, not individual patients, because a single patient can have multiple pathways open at once. The difference between pathways and patients in Wales is discussed in more detail in the blog ‘Chief statistician’s update: explaining NHS activity and performance statistics‘.

How comparable are these headline statistics? What comparisons can be made?

Because the Northern Ireland and Scotland statistics do not include all stages of patient pathways like in Wales and England, it’s not possible to make direct comparisons across the headline statistics for all four nations on the total number of patients waiting.

Conceptually, the Wales and England measures for totals waiting are much closer. However, within these measures there are still some significant differences between the two countries.

The key difference between England and Wales concerns some types of diagnostics and therapies. In England only ‘consultant-led’ pathways are reported, whereas in Wales some non-consultant led pathways are counted as well. We believe that most of these pathways in Wales fall into two groups: direct access diagnostics and Allied Health Professional therapies (for example physiotherapy, osteopathy). We estimate these account for at least 88,000 of the 755,000 open pathways in September 2022. This is based on the types of activities we’ve been able to identify, but the true number could be higher.

If we remove these 88,000 pathways from the total open pathways for Wales, that leaves around 666,000 open pathways. Based on our current understanding, this would be a more comparable measure with England than our regular headline statistic (though as stated, there may be more than the 88,000 non-consultant led pathways that we’ve not yet been able to identify). For Wales this would be equivalent to around 21% of the population, or one open pathway for every 5 people. The 7.1 million pathways in England are equivalent to 13% of the population, or one pathway for every 8 people.

We’ve shown these figures here as rates to help provide context and aid comparison. But it’s important to remember that for both Wales and England these are counts of pathways not individual patients. A single patient can have multiple pathways open at once, so it’s not true to say, for example, that one in every 5 people in Wales is waiting for treatment.

What we’re doing to understand more

There will be further differences in coverage and definitions between the nations which we cannot yet measure with confidence. However, these are likely to be on a much smaller scale than the diagnostics and therapies described in this blog post. There will be examples where coverage is wider in England and others where coverage is wider in Wales, but they are unlikely to materially affect the totals.

As there will continue to be considerable interest in statistics on NHS activity and performance across the UK, we plan to keep investigating these differences. This will include more in-depth work on waiting times, but also other elements of NHS activity and performance such as emergency care.

We are working across the UK with colleagues from each of the four nations to better identify and communicate where differences exist and support you in making meaningful comparisons. Over time we will provide further updates via this blog as we learn more.

Stephanie Howarth
Chief Statistician