THE latest hospital waiting-time revelations follow a pledge five years ago by Nicola Sturgeon, as health secretary, that the "opaque and secretive" regime surrounding NHS waiting lists would end.

In September 2007 Ms Sturgeon scrapped a system that meant tens of thousands of patients were, for various reasons, excluded from waiting-time guarantees, assigned a code and kept out of official results figures.

Instead she brought in a clock that ticks for each patient but can be stopped if, for example, they cannot have surgery due to a holiday or because they are too unwell for treatment.

It means people do not lose the right to treatment within a time limit, but the NHS is not punished for failing to meet targets when a delay benefits the patient.

But just as concerns were raised over whether patients were legitimately put on the code list, with NHS Lothian hit by a waiting-times scandal questions are now being raised about why people's clocks are stopped, turned back or reset.

The document leaked to The Herald shows questions asked by staff who track waiting times for cancer patients about such fine-tuning of figures.

It shows days are subtracted from the real time people wait for treatment because an investigation into their condition has failed to give a clear result and a repeat is required.

People who choose to wait for treatment closer to home have their clocks adjusted as if they had attended the earlier appointment further away.

When clinicians change their mind about the way to treat a patient, the health board is advised on how to fix the clock to negate the impact of that delay.

The document, known as the "Query Log," contains many instances when trackers are clearly asking for guidance on grey areas: people and diseases are nothing if not varied and complicated.

Many questions suggest efforts to do the best for patients and many responses seem entirely valid. Others, however, suggest the pressure to hit targets creates a temptation to fiddle the figures.

Someone from NHS Tayside asks if they can make allowances for the Christmas and New Year public holidays and for an episode of snowy weather that made it hard for patients to travel to appointments. They say: "Surely these are the sort of occurrences for which we should be allowed to adjust? We have no control over them and would meet targets, which we now won't due to these adverse conditions."

On another occasion, NHS Lothian writes: "Have had a couple of breaches of the target due to equipment failure. Can any of these patients be excluded from the target?"

In both cases the answer is "no", but other adjustments are sanctioned, such as adjusting the clock because the health board does not fund the "best treatment option" for some people with kidney tumours, and a business case needs to be prepared and approved before the treatment can proceed.

The Government's target is for 95% of patients to start treatment within 62 days, the 5% tolerance reflecting the fact that it might not be clinically appropriate for some patients to begin treatment within that time frame. Moving the hands on clocks should not, therefore, be necessary for this reason.

On page eight of the latest official report on cancer waiting times, NHS statisticians say adjustments are applied to take into account periods of patient unavailability and medical suspensions. In total, 1058 adjustments were made between April and June this year. The nature of these changes is arguably somewhat "opaque".