The Public Audit Committee has investigated the current drive to try and prevent more pensioners being admitted to hospital by providing better services in the community.
Their report, published yesterday, asks officials to fill in gaps in information - such as how much achieving this goal depends on cutting spending on hospital care.
They also want to know how the government will support NHS boards to release money from hospitals to invest in the community.
NHS Greater Glasgow and Clyde told the committee the idea of it spending less on hospital care was "undermined" by political goals such as waiting times targets.
The report also notes that when in the 1980s the care of mental health patients was moved out of hospitals, bridging finance was used to run services in both while the change took place. It said hospital beds only closed once there was evidence that they were no longer required.
The audit committee says spending on health and social care for older people will need to rise from approximately £4.5 billion in 2011/12 to nearly £8bn by 2031 to meet rising demand, but the overall annual Scottish Government budget is being reduced and is not expected to return to 2009/10 levels until 2025/26.
The Herald is campaigning for a review of NHS and social care capacity and a plan to show what is required to meet the needs of the growing elderly population in hospitals and the community.
Hugh Henry, committee convener, said: "The committee recognises the long-term policy of governments to shift care from hospitals to home or the community continues to be a challenge. This is made all the more difficult by rising demand from Scotland's ageing population and budgetary pressures.
"This challenge is one of the biggest facing Scotland. It means it is vital progress is made in the reshaping care for older people programme as it involves changing the way care is provided whilst continuing to meet current and future demands within the budget available."