With most of its 230 beds empty, Meadowlands Hospital Medical Center in Secaucus has announced that it will lay off more than 100 employees, or about 20 percent of its workforce, according to its center's chief executive, Thomas Considine. With patient census today at 48 but "trending in the low 30s for the past week," the hospital is "grossly overstaffed, Considine told The Star-Ledger this evening. In a letter that went out to its staff on Tuesday night, Considine said that for every patient there are 17.1 employees, a situation he called "an intolerable. . .efficiency ratio." The average hospital has 4.72 employees for every patient, according to the letter.