Each month we publish a wide range of NHS secondary care statistics, from urgent and emergency care to diagnostics, therapies and NHS waiting lists. We’ve recently made some changes to improve the relevance and timeliness of our data and to reflect a change in the way 999 ambulance calls are managed.
Darllenwch y dudalen hon yn Gymraeg
More timely NHS waiting list data
There’s great interest in referral to treatment (RTT) waiting list figures, particularly around long waiting times. The official measures are published with a lag of around 7 weeks, meaning for example, June’s final figures are released on 21 August. However, given the attention on these statistics and the Welsh Government’s commitment to reducing the longest waits, there is public value in making data on this topic available earlier. We’ve explored how we can provide figures for the following month in the statistical report based on the latest available data, and from August we’ll include estimates for July for the total number of RTT pathways waiting and those waiting more than one and two years.
These measures will be provisional, and they may change to some extent before the official statistics are published. However, we believe the provisional figures will provide a reliable and timely indication of changes for the month ahead.
A new way to measure ambulance performance
In July 2025 the Welsh Ambulance service changed the way it manages 999 calls. Two new response categories were created for the most serious calls, replacing the previous red category. New performance measures were also introduced, meaning the previous data series ends in June 2025. From August 2025 we’ll be publishing official statistics based on the new model, with further changes to come later this year.
From 2016, ambulance calls were categorised as either red (immediately life-threatening), amber (serious but not life-threatening) or green (non-urgent), with red calls subject to an eight minute target for an emergency response. Following a clinically-led review of the target, the Cabinet Secretary for Health and Social Care announced changes to the way ambulance performance is measured, to be piloted from July. The ambulance clinical response model, which determines how calls are prioritised, was adapted to reflect the new approach. The changes are intended to better reflect the range of patient scenarios, with new measures bringing a focus on clinical outcomes and quality of the service.
New call categories and measures
On 1 July 2025 two new categories, Purple: arrest and Red: emergency, were introduced to replace the previous red category. Purple calls are for patients in cardiac or respiratory arrest. Red calls are for patients with major trauma or who are at significant risk of cardiac or respiratory arrest if they do not receive a rapid response. There is currently no change to amber and green calls, however new categories reflecting different types of less urgent calls will be introduced later.
A wide range of ambulance indicators will be published by the NHS Joint Commissioning Committee. A subset of measures will be established as official statistics and published by Welsh Government. The official measures for the purple category will be:
- number of calls
- return of spontaneous circulation (ROSC) rate
- median time to identify cardiac arrest
- median time to commence CPR instruction
- median time for defibrillator arrival
- median ambulance response (target 6 to 8 minutes)
- 90th percentile ambulance response (target <20 minutes)
The ambulance service’s aim in responding to purple calls is improving return of spontaneous circulation (ROSC) rates for patients in cardiac or respiratory arrest. The main clinical measure is therefore the ROSC rate – the proportion of patients to have a heartbeat restored after a period of cardiac arrest.
Ambulance response times will be measured by the median, where half of responses are quicker and half are slower and the 90th percentile, where 90% of responses are quicker and 10% are slower. The median response time target will be 6-8 minutes and the target for the 90th percentile will be 20 minutes.
Median times will also be reported for the identification of cardiac arrest, for call handlers to commence CPR instruction and for the arrival of a defibrillator. These are key indicators in relation to patients’ chances of survival.
The official measures for the red category will be:
- number of calls
- median ambulance response (target 6 to 8 minutes)
- 90th percentile ambulance response (target <20 minutes)
- outcome measure(s) – to be determined
The intention for the red category is to prevent patients at risk of cardiac or respiratory arrest from deteriorating into arrest. As with purple calls, timely ambulance response is key, and the same response time measures will be reported, against the same targets. Clinical outcomes measures will be considered later.
Ambulance data reporting and future changes
Official statistics should be accessible and relevant. To support the public’s understanding of the changes and the impact on services, we’ll provide the new ambulance performance measures in our monthly NHS activity and performance statistical release, and we’ll publish data by Local Health Board on our StatsWales service.
Later this year further changes will be made to the ambulance response model. Non-purple or red calls will be re-categorised reflecting the different types of less urgent patient conditions, and corresponding performance measures will be developed.
Data for all of the new measures will be collected and quality assured by the Welsh Ambulance Services NHS Trust (WAST) and provided to Welsh Government for publication. Please contact stats.healthinfo@gov.wales with any questions about the new response model or performance measures.
Stephanie Howarth
Chief Statistician