Essential insight into England’s biggest health economy, by Ben Clover.

The figures for the accident and emergency performance in November will not be released before the general election.

But data from the Royal College of Emergency Medicine indicates a further step change downward in performance on the crucial type-one A&E target.

The RCEM president and emergency medicine consultant at St Thomas’ Hospital, Katherine Henderson, said the growth, particularly in trolley waits, was shocking.

The college said the way trolley waits were recorded needed to change as the English NHS only starts the clock once a decision to admit has been made, understating the total number of very long waiters.

Dr Henderson pointed out that “corridor care” meant people were often getting “life changing news while stranded on a trolley. This cannot be right.”

Type-one performance went as low as 74.5 per cent in October – a quarter of people seen in consultant-led units had waited more than four hours – and London had four of the 10 lowest performing trusts.

The bad news for the capital is that the lowest two of these, Barking Havering and Redbridge University Hospitals Trust and King’s College Hospital Foundation Trust, each run two type-one units serving large populations, three of these in busy outer London areas serving older populations. The other two trusts are Hillingdon Hospitals FT and Croydon Health Services Trust.

Another striking feature in the performance of these London trusts is the distance between their type-one performance and their all-types performance. The latter includes the work done by the urgent care centres that sit alongside the consultant-led A&E. Nationally, the difference is less than 10 per cent points (83.6 per cent for all-types, 74.5 per cent at type-ones).

In three of those four London trusts the difference is more than double that.

Croydon Health Services Trust saw 84.1 per cent of all-types patients within four hours, but that figure falls to 59.6 per cent for type one. The way the trusts record their data could be an issue here.

Obviously people breaching in a type-one is bad — but the percentage performance also depends on their ratio to people recorded as a type-one who don’t breach.

To take a comparison at random, the Royal Free, which also runs two units, had a total attendance in October of 25,000, compared to Croydon’s 20,000.

Royal Free records 21,000 of these attendees as type one, while Croydon records 7,500 of its 20,000 attendances as type one. Meanwhile, 4,000 of Royal Free’s total attendance are recorded as type three, compared to 12,000 at Croydon.

Seems odd that Croydon would have triple the minor injuries attendances at its one unit than Royal Free would have across its two.

Croydon’s all-types performance at 84.1 per cent is actually better than the Royal Free’s 79.7 per cent. But because more-or-less four-fifths of the latter’s attendances are recorded as type-ones, it can set its breaches against a higher denominator. The gap between performance of type one and all-types at RF is 3.8 percentage points.

Four of the five best performing trusts in the capital for all-types have the lowest difference between their type-one and all-types scores.

Whatever happens with the proposed scrapping of the four-hour A&E target next year, a new system will surely raise its own questions and inconsistencies.