The percentage of elderly people confined to nursing homes is remaining stable even though the raw numbers are rising because of an aging population, according to "Health United States 1987," a report issued by the Department of Health and Human Services.

There were 1.3 million nursing home residents at least 65 years of age in 1985, up 200,000 from 1977 when the last nursing home data were collected.

Despite growing political attention to the issue of financing long-term care for the elderly, the figures in the 207-page "Health United States 1987" report underscore that a tiny minority of all elderly people actually wind up in nursing homes.

The report notes that the 1985 nursing home population reflects about 1 percent of Americans 65-74 years old being confined to institutions and about 22 percent of those 85 years and older. It said both percentages are essentially unchanged from the 1977 survey.