Columbia subject headings:
Medical care--Utilization--United States--Statistics.
Medical care--Utilization--United States.
Medicare--Statistics.
Medicare.
Harvard subject headings:
Medical care--Utilization--United States--Statistics
Medical care--Utilization--United States.
Medicare--Statistics.
Medicare.
Older people--Medical care--United States.
Poor--Medical care--United States
Princeton subject headings:
Medical care--Utilization--United States--Statistics.
Medical care--Utilization--United States.
Medicare--Statistics.
Medicare.
Statistics.