At the end of March, the English NHS hit its interim target that 65% of the referral-to-treatment (RTT) waiting list should fall within 18 weeks, an achievement that NHS England are understandably very pleased about.

Analysis produced for Health Service Journal by Dr Rob Findlay, Director of Strategic Solutions at Insource Ltd and founder of Gooroo Ltd

More importantly, in March the waiting list shrank faster than the current recovery trajectory, meaning the NHS was briefly on track to restore the ’18 weeks’ standard in 2029 as the government has pledged. The improvements helpfully focused on patients without a diagnosis and decision to admit, as more patients were seen and discharged from outpatients and diagnostics.

All of which is good news, but it is not the whole story so let’s take a closer look.

The current trajectory towards restoring ’18 weeks’ in 2029 required the NHS to overcome seasonal growth in the waiting list of around 35,000 in March, and shrink the waiting list by a further 43,000 patient pathways. It achieved that and more, overcoming seasonal growth and shrinking the list by a further 110,000 pathways – a substantive improvement of around 145,000 patient pathways.

But something else happened in March: unreported removals from the waiting list spiked from the usual 250,000 per month to a whopping 350,000. So most of the 145,000 improvement was accounted for by the extra 100,000 unreported removals.

In short, March’s waiting list reduction was caused more by ‘validation’ removals, than by actually seeing and diagnosing patients.

Validation is a legitimate activity, and when it is done well it keeps the waiting list consistently accurate. However when there is a huge spike in unreported removals, as in March, it is legitimate to question whether all of those patients were removed for the right reasons. Were so many patients really on the waiting list in error, after 12 months when validations have been specifically encouraged and incentivised?

If some of those patients were removed from the waiting list unjustly, they will surely reappear on it when they are re-referred. That would undo some of March’s apparent success, but it would also mean that their care has been delayed, and they may be at clinical risk as a result. The goal of validation should be accurate waiting list data, not the appearance of achieving a target.

In the following discussion, all figures come from NHS England. You can look up your trust and its prospects for achieving the waiting time targets here.

The numbers

After adjusting for non-reporting trusts, the waiting list change was -110,073 in March, better than the latest trajectory for restoring 18 weeks which required -42,745. Both figures are in addition to overcoming the usual seasonal growth of +34,735 in March.

But there was a huge spike in unreported removals, from the more typical 250,000 to some 350,000 in March (blue line, right hand axis below). The extra 100,000 unreported removals accounts for the majority of the improvement seen in March (though not all of it).

The waiting list reduction caused the list size to break free of the levels seen in recent years, and head downwards towards the much smaller list that would make restoration of the ’18 weeks’ standard possible.

The RTT waiting list breaks down into two main stages: from referral, up to diagnosis and decision to admit; and from decision to admit, up to admission for treatment as an inpatient or daycase. The waiting list for the latter stage has not budged for two years. Crucially it is not growing either, which means that the NHS is not losing control of this resource-heavy waiting list.

The overall RTT list is falling, but not for patients with a decision to admit, so it follows that the waiting list is falling for patients who do not have a decision to admit. These patients are waiting for outpatient consultations, diagnostics, and outpatient procedures. It is sensible to tackle this part of the waiting list early, not least because undiagnosed patients come with clinical risk (for instance, an estimated 25,298 will eventually receive an unexpected cancer diagnosis).

Waiting lists shrink when patients are seen, treated and removed faster than they are added to the list. The next chart shows that patients are not being added to the list significantly faster than in recent years, so March’s improvements are not attributable to a reduction in demand.

Patients were discharged from outpatients and diagnostics significantly faster in March, confirming that the waiting list reductions were not entirely caused by ‘validations’ and there was also a surge in real patient care.

However, patients were admitted for inpatient and daycase treatment at a slower rate than in recent years. This will need to ramp up at some point to restore the ’18 weeks’ standard by 2029. The longer it is left, the faster that will need to happen when the time comes, and this work is expensive and capacity-intensive.

Waiting times fell by 1.1 weeks to 38.3 weeks RTT. For those patients without a diagnosis and decision to admit, waiting times fell by 1.2 weeks to 36.1 weeks. This is what matters to patients, and it is far too long if the eventual diagnosis is unexpectedly cancer.

Waiting times are a function of both the size and shape of the waiting list, and the next chart is a measure of the shape. The waiting list trajectory in the first chart above assumes the shape will improve to 2013-16 levels in the chart below; this can be expected to happen naturally as waiting times improve, but this is not guaranteed.

Waiting times fell in all specialties, which is welcome.

Looking at all of the thousands of local specialties within trusts across England, March saw a sharp fall in waiting times everywhere. But waiting times remain historically long: the February 2020 line below shows the position just before the covid shutdowns, and April 2013 shows the best ever achieved when 92 per cent of the RTT waiting list was below 15.8 weeks. The distribution needs to fall somewhere between the two by March 2029.

Referral-to-treatment data up to the end of April is due out at 9:30am on Thursday 11th June.