A role-playing program helps high school students resist peer pressure and decide against using drugs, tobacco and alcohol, according to a study from the national Centers for Disease Control.

The program, called Teenage Health Teaching Modules, targets the small number of high-risk behavior patterns primarily formed in childhood and associated with the nation's major killers, heart disease and cancer, said Dr. Lloyd Kolbe, director of CDC's division of Adolescent and School Health."A relatively small number of behaviors contribute enormously," Kolbe said. He named tobacco use, excess fat consumption and a sedentary lifestyle among the chief risk patterns adopted in childhood.

Results of the $447,000 study, released Thursday, show how a role-playing program outlining the risks of unhealthy decisions by teenagers can help people make healthy choices, Kolbe said.

"The kids vicariously put themselves in situations where they're challenged to face behaviors," he said. "It helps them understand what it feels like to be in a pressured situation and gives them a sense of control and responsibility."

Health officials said the effects of the program on high school student choices - about smoking, drinking, using illegal drugs and chewing tobacco - were moderate by strict statistical measure, but the extent of behavioral change was considerable.

The evaluation, conducted from 1986 to 1989, included 2,440 high school students and 2,366 junior high or middle school students from 149 schools in seven states.

No specific schools were named.