Rising costs last year forced a record 79 hospitals to close their doors, the American Hospital Association reported today. The closings, most in hospitals with fewer than 100 beds, were heavy in four southern states but were evenly split overall between rural and urban areas, the hospital group said. ``Hospitals that barely break even or continually lose money cannot buy needed medical equipment, replace deteriorating buildings or add important services,'' Carol McCarthy, president of the Chicago-based organization, said in a statement. Federal Medicare payments, which represent 40 percent of a hospital's income, may be partly to blame for the closings, she added. ``Hospitals saw the price of goods and services they purchase rise 22 percent between 1984 and 1988 while Medicare raised the prices its pays hospitals ... only 11 percent,'' she said. Of the 79 hospitals that closed in 30 states, 35 were for-profit, 30 were non-profit and 14 were government-owned, the association said. Twenty-five hospitals closed in four states: Arkansas, Louisiana, Oklahoma and Texas. Most of the closed hospitals ranged from 25 beds to 99. ``In the past year, nearly seven in 10 rural hospitals in this country lost money caring for patients, and 50 percent of urban hospitals operated in the red,'' Ms. McCarthy said. Jan Shulman, an AHA spokeswoman, said the 42 hospitals that closed in 1986 was the previous record. In addition to the 79 hospitals that shut down, 17 speciality outlets also closed in 13 states in 1987. Most were rehabilitation or long-term care centers, said the association.