Broadway, the legendary "fabulous invalid" of show business, is suffering an apparent relapse, due more to the closing of a half dozen shows and the paucity of new ones than to the Persian Gulf war.

Attendance at Broadway theaters took a 20.3 percent dive last week and was expected to keep dropping this week, according to Variety, the show business weekly. In contrast, 25 shows touring the nation reported only a 6.9 percent slide in business.Harvey Sabinson, executive director of the League of American Theaters and Producer, described the drop in Broadway business as "not that precipitous."

"I attribute the drop in attendance more to the closing of shows than to the war. The drop averages out to only a 4 percent if you take into account the audience loss due to closings."