The greater Dublin area and the southeast have the lowest levels of community healthcare in Ireland.
A new ESRI report also finds there is an unequal supply of community health and social care in Ireland.
The evidence could inform policies, such as Sláintecare, which aim to move patients away from acute hospitals.
The ESRI's Brendan Walsh says the west and south of the country have a better supply of community care.
"In this report, we've concentrated on services which are provided outside of the hospital within the community," he said.
"We've looked at the supply of various medical professionals, such as GPs and physios and also medical services such as nursing home beds and home care.
We find quite large inequalities across the country and the provision of healthcare does not meet with population demand.
Sinn Féin's health spokesperson, Louise O'Reilly, says the report shows a big lack of resources in community healthcare.
"Slaintecare talks about the need to move from hospital-based to community-based care but that is not going to work unless we actually start shifting services into the community," she said.
"What this ESRI report shows is that in terms of the key delivery for primary care in terms of people actually being on the ground that there are serious deficits right across the State."
