Some years ago, when Gordon Brown was Chancellor, I met his right-hand man Ed Balls at the Treasury to talk about waiting times. It is difficult to imagine now but, back then, inpatients waited up to a year for their operations. Ambitious Ministers wanted to cut this radically.

I advised that a 9 month target would be easy to achieve at minimal cost, but a 6 month target would require substantial extra resources to cut the size of the waiting list. When I stressed the costs involved, I was surprised to find that Mr Balls was unruffled. But of course, back then, I had no idea just how much extra resource they were willing to commit.

Soon after our meeting, the Labour Government opened the spending floodgates and poured money into the NHS, announcing that they effectively wanted to abolish waiting lists. A brutal performance management regime was created with monitoring, threats, naming and shaming. As NHS expenditure trebled from its 1997 level, capacity expanded, waiting lists came down, and the 18-week referral-to-treatment waiting time was (with only a few exceptions) achieved across England.

A report by the Nuffield Trust shows that both money and pressure were necessary in achieving 18 weeks. England achieved short waits, but Scotland, Wales and Northern Ireland did not (despite spending more money and having more staff). In short, both blood and treasure were spent; lots of it. The 18-week target was hard-won.

Times have changed. The money has run out, and a new Government has been elected to clean up the mess. At the Department of Health, the new Secretary of State has wasted no time in shaking things up with a new Operating Framework for the NHS.

The changes to the 18-week target caught the headlines. They are “a very risky message that waiting no longer matters”, said Lord Crisp, a former NHS Chief Executive. “There is now a real risk that there will be a slipping back on the big improvements in waiting times of the last 10 years”, said Chris Ham, the King’s Fund Chief Executive.

So what does the new Operating Framework actually say? The key passage is:

18-weeks waiting times

7. NHS organisations have made significant improvements in access to elective care. Average waiting times now need to be reduced, in line with international experience. Accountability to patients and greater information transparency, through patient choice and the move towards GP-led commissioning, should now make long waits unacceptable. Performance management of the 18 weeks waiting times target by the Department of Health will cease with immediate effect.

8. To maintain progress during 2010/11:

• commissioners should maintain the contractual position and GPs and commissioners will want to ensure that any flexibility to improve access reflects local clinical priorities; and
• referral to treatment data will continue to be published and monitored. Commissioners will want to use the median wait as an additional measure for performance managing providers.

9. Patients’ rights under the NHS Constitution will continue, as will the accompanying legal requirements to ensure that providers are achieving the waiting time rights. We are considering to what extent amendments are required, and if so, we shall carry out a full consultation in due course.

So the brutal performance management regime has come to an end, to the relief of Chief Executives who feared the phone call if the target was breached on their watch. In its place are the NHS standard acute contract (with financial penalties of up to 5% of total elective income for breaching 18 weeks) and the NHS Constitution pledge, backed up by the Waiting Time Directions 2010 (which require PCTs to “take all reasonable steps” to arrange an earlier appointment if a patient complains she is waiting too long).

These measures have the potential to be firm, if they are actually implemented locally. However the experience of the past suggests that, when the going gets tough, too often the easiest option for both commissioners and providers is to let the patients wait. We shall have to wait and see how well this hands-off approach works.

What are we to make of the waiting time statistics mentioned in the revised Operating Framework? First it talks of the need to reduce average waiting times. Average waiting times are directly proportional to the size of the waiting list divided by the rate that patients are added to it (assuming casemix remains constant). So in practical terms that means that waiting lists must rise no faster than referrals. A sensible measure.

But then it asks commissioners to monitor median waiting times. This means that if you take all your patients, and sort them in order of their experienced waiting times, then the middle one (50% of the way down the list) has the median wait. Is this a sensible measure? Consider this: if 20% of the patients are urgent, and the rest are broadly seen in turn, then the median wait (the 50% wait) will be close to the maximum wait. But: if 70% of the patients are urgent, then the median wait will be very short because it is experienced by an urgent patient. So monitoring median waiting times makes little sense at first sight.

It gets worse. Let’s say 55% of patients in, say, plastic surgery are being admitted as urgent patients, so your median wait is in the urgent zone and very short. But you examine the casemix carefully and find that some routine patients are being misclassified as urgents, which is clinically unjustified and causes other routines to wait longer. So you put this right, obeying the contractual guidance that:

9.3 Providers are expected to follow recognised waiting list management practice such as taking patients of equal clinical urgency in turn.

So now only 45% of these patients are being admitted as urgents, which is a more accurate reflection of the casemix. But your median waiting time has increased dramatically, because now it reflects typical routine waiting times instead of urgent waiting times. Improving your scheduling has sent median waits in the “wrong” direction.

So on 18-weeks, the new Operating Framework can be criticised on two grounds. Firstly the lifting of central performance management is likely to cause the target to slip once the financial squeeze takes effect; at worst, maximum waits could rise by one week every week. Secondly, the suggestion that commissioners should monitor median waiting times reflects ignorance of scheduling dynamics; I would suggest that if a centile is to be monitored then it should not be the 50th, but a high one such as the 90th centile. That would reflect more accurately the provider’s success at managing scheduling.