Christmas Eve is notable in many respects, not least in the nation’s hospitals. On no other day in the year are a higher proportion of patients admitted through Accident and Emergency units and subsequently discharged within hours. The reason for this is obvious. Most people would prefer to spend Christmas Day itself with their families rather than with strangers in an institution.

In England, however, the numbers of people entering and then rapidly leaving hospitals has been increasing markedly on almost every date in the calendar across the past few years. This is not the case in Scotland or Northern Ireland and has only recently emerged as a trend in Wales. As we report today, there seems to be a logic, of sorts, behind these differences. They are caused by a target for dealing with those who present themselves at Accident and Emergency which applies in England and, more latterly, the Principality, but not north of the border or in Ulster.

This is a classic saga of how the best of intentions becomes the worst of policy outcomes. Surveys of patients at the beginning of this decade revealed that one of the principal complaints held, understandably, was about the length of time a person might be kept waiting to be assessed at an Accident and Emergency facility. Keen to be responsive to this concern, Whitehall decreed that no fewer than 98 per cent of patients should be looked at within four hours of their arrival in a hospital and formally admitted, treated on the spot and sent home or discharged completely.

The realities of life in a busy hospital, though, have ensured that what seems to be a reasonable instruction has been the source of a perverse incentive. It is common for patients not to meet staff until the four hours have almost expired and an instant decision has to made about what to do with them so that the deadline is satisfied. All too often, doctors and nurses will “play safe”, admit the man or woman involved “just in case” there is more wrong to them than initially meets the eye, only for it to be determined very shortly afterwards that this is not required.

This is more than a strange bureaucratic exercise. The financial consequences are substantial. A primary care trust might have to pay as much as £1,000 for every admission (even if it is just hours), compared with much closer to £100 if a patient is promptly patched up and sent on their way. The cost of what are in essence unnecessary admissions, an analysis by the CHKS Group, an independent source of healthcare information, indicates, has been about £2 billion over five years.

This saga illustrates the difficulties that come with a target-based culture in the health service. On the one hand, it could be argued that the target has “worked” in that patients are being seen faster than in the past in Accident and Emergency units. Yet the surely unacceptable price of this has been a rushed form of diagnosis in which people are admitted to hospital more as as a strategy for satisfying a target than because it makes sense. The net outcome is wasted public money.

It would be unwise to conclude that targets are of no value to the NHS whatsoever. It is an easy populist jibe to insist that they must all be swept away in favour of allowing “the professionals” to run hospitals as they see fit. What might be better, nevertheless, is a different balance between inevitably abstract targets and external inspections of the manner in which hospitals are organised. Best practice might be better advanced if the system of oversight in the NHS was closer to that employed by Ofsted in schools with a short, sharp investigation conducted at short notice. As matters stand, ministers need to reexamine the four-hour target which they championed and see if it can be made more flexible and effective. For it is a sick system which encourages hospitals to admit in haste with the expense borne at leisure.