How heavily do Americans use health care services? The two chief measures — visits to a doctor and nights spent as a hospital patient — give us a good idea.

According to the Survey of Income and Program Participation (SIPP), 84 percent of Americans aged 16 to 64 visited a doctor at least once during a 24-month period between 1990 and 1992; 14 percent spent one or more nights as a patient in a hospital. All in all, these Americans made 1.1 billion doctor visits (or 7 per person) and spent 154 million nights (1 per person) in a hospital during the 2 years. (Visits to the dentist and doctor contacts in a hospital were not considered doctor visits.)