The National Center for Health Services Research and Health Care Technology Assessment conducted a study to examine how Americans use health care services and to determine national patterns of health expenditures and insurance coverage. Data were obtained from the National Medical Care Expenditure Survey interviews conducted with 14,000 randomly selected households at 6 times over an 18-month period during 1977 and 1978. Data were analyzed to determine annual expenses for personal health services and mean health care expense per person by selected demographic and socioeconomic characteristics. The data showed that inpatient hospital and physician care consumed almost 60% of expenditures during 1977. Persons with expense spent $594 on the average for health services, with the family and private insurance together assuming almost two-thirds of the cost. On an individual basis, females of all ages incurred a higher percentage of out-of-pocket expense than did males. Mean expense per person with personal health care expenditures was also higher than the $594 national average for blacks, for those with family incomes below $12,000, and for persons living in the Northeast and the West. Between 1970 and 1977, increases in health care expenditures after adjustment for health care price inflation were particularly noticeable for the population age 55 and older and for the inpatient component of services. (Author/NB)