Concern over the time police officers spend at A&E
Concerns have been raised about the amount of time on duty police officers spend escorting patients to accident and emergency departments.
New Police Scotland research shows a typical A&E visit can take up more than five hours of a police officer's time.
Pictures shared on social media show significant numbers of police vehicles parked outside hospitals across Scotland for hours at a time.
Police unions have described the situation as "farcical".
David Hamilton, vice chairman of the Scottish Police Federation, said: "Our members are telling us that they are now regularly left escorting people to hospital or waiting around because there is nobody else to do it."
Officers are called to A&E departments for a variety of reasons such as assessing people for custody, taking injured people for treatment and escorting people for mental health assessment.
They will also attend to support medical staff with violent or abusive patients.
But concerns have been raised that the amount of time frontline officers are spending in emergency departments has increased in recent years.
Police Scotland said it had been conducting a study of the amount of time frontline officers spent in A&E but it was not yet ready to release the figures.
In December, Deputy Chief Constable Fiona Taylor disclosed to a police conference the initial findings of the study, which is looking into emergency department callouts in two of the 13 regional policing divisions into which the national force is divided.
DCC Taylor said the high-level analysis showed that in the space a one month period, officers from the two divisions spent more than 1,500 hours within an emergency department setting.
On average each visit took in excess of five hours, according to the research.
Police Scotland would not say which divisions were involved in the study so the number of officers included is not known.
Majority of calls do not involve a crime
Scotland's A&E departments admit more than 1.6 million patients a year.
The ambulance service said its priority was to respond to patients with life-threatening conditions.
Police said that was why they were often left to take vulnerable people for treatment, including those with mental health issues.
Four in every five police 999 calls do not involve a crime and are about welfare and mental health incidents.
The new service aims to help people on the spot or direct them to services more quickly, a task that would ordinarily involve officers taking a person to accident and emergency and waiting with them for assessment.
Police Scotland is finalising its study into officers attending A&E and said the results will be considered alongside the street triage pilot scheme in Glasgow which is now complete.
Analysis: The street team triage solution
By Lisa Summers, Scotland Health Correspondent
Last year I went on a late shift with officers in Glasgow running a pilot mental health project that aims to take some of the pressure off frontline staff.
Over the evening I watched as the specialist "triage" team, made up of a police officer and paramedic, repeatedly flicked the blue light switch on their patrol car and sped off to calls.
In one case they arrived at a block flats in Govan where a man was threatening to take his life.
There were two officers already at the flat when we arrived but the specialist team took over and I got chatting to the two regular officers on their way out.
Both were incredibly positive about this project as it allows them to get on with their other duties, knowing the caller is getting the specialist help they need.
On any other day they say they would have had to take the man to A&E and wait with him, probably for the rest of their shift.
But after 90 minutes the team is done; community psychiatric nurses have been to visit and the man is being taken to a specialist hospital for further assessment by a consultant.
Crucially, it bypassed any need to go to A&E.
The triage team finished at 02:00 and as I was packing up I saw the two officers I met at Govan rushing out to attend another 999 call where a mental health incident had been identified.
This time they would have no triage back-up and would likely end up in A&E.
'Situation is getting farcical'
The Scottish Police Federation's vice chairman told BBC Scotland: "At times the highest concentration of frontline police resources is in our hospitals and that can't be right."
Mr Hamilton said: "Police officers can't and won't walk away from people in need and as the service of last resort we increasingly see ourselves impacted by the contraction of other public services."
He claimed the ambulance service had changed its protocols which meant it was downgrading the priority given to callouts where a police officer was in attendance, adding the force was "neither trained nor resourced to step into be an ambulance service".
But the Scottish Ambulance Service categorically denied this was the case.
A spokesman added: "We do not downgrade calls - if a patient requires urgent medical attention, we will always send an ambulance.
"We prioritise calls to ensure we respond to patients presenting with life-threatening conditions first."