Police staff and officers are not happy. Fully one in three of them are thinking about quitting. That, at least, is the headline finding of a new, full and independently conducted survey of Police Scotland employees.

This - in the words of Brian Docherty, chairman of the Scottish Police Federation - should be wake-up call on the impact of austerity on the new national service.

Mr Docherty's organisation represents rank-and-file officers. They might count themselves lucky. In England and Wales, policing has suffered deeper and more damaging cuts than in Scotland. Here the national force - and the savings it has brought - have protected services. But there is a limit to that.

And English cuts have a strange impact too. Fewer police officers south of the border - numbers in Scotland have, controversially, been frozen - have had an unintended negative impact on pensions here. Half of those people who suggested they may leave cited pensions.

But the big police merger must have had its impact on morale. Civilian staff have born the brunt of "savings". But officers too have seen changes in the way they work. Reform has a cost as well as a benefit. Deputy Chief Constable Neil Richardson, always a calm voice in policing, has acknowledged this. "Change," he said, "will of course have an impact on staff.

"This survey makes clear that changes to police officer pensions, issues around health and wellbeing, information and communication also have an impact to staff."

Only a tiny number of Police Scotland's employees - six per cent - feel their well-being is important to the organisation. That number has to change.

It is to the credit of Mr Richardson and the Scottish Police Authority that they have carried out this survey. Not all its results are negative.

Politicians must not rush to assume that findings - positive and negative - are a result of police reform. Caution should be shown before anyone either casts blame or takes credit.

That is because there are no robust surveys from the old forces that we can use to compare the mood now and the mood back in, say, 2013.

Staff retention is a real problem in Police Scotland. Too may police officers leave the organisation without serving their full three decades. This is especially true of women and especially true in parts of the country where there are other employment opportunities, such as the north-east.

This survey - and its 50 per cent return makes its findings highly robust compared with similar exercises elsewhere in the public sector - must be treated seriously.

It may not reveal whether things are getting better or worse now. But it may do so in the future.

The survey offers a baseline upon which the new chairman of the Scottish Police Authority, Andrew Flanagan, and the next chief constable, whoever he or she may be, must be judged.

The early signs are positive. Mr Flanagan has said staff satisfaction will be taken in to account in selecting the replacement for the outgoing chief constable, Sir Stephen House.

This survey, therefore, will become a vital tool in measuring the success of our police service. Police Scotland has a corny motto. Its job, it says, is keeping people safe. To do so it must also keep its own people happy.