Annual chest X-ray screenings do not significantly reduce the number of people who die from lung cancer, researchers said. Martin M. Oken of the University of Minnesota and his colleagues published their findings in a paper that will appear in the Nov. 2 edition of the Journal of the American Medical Association.

Researchers tracked over 150,000 participants every four years over the course of 13 years starting in 1993. Oken and his colleagues observed 1,696 cases of cancer in the screening intervention group and 1,620 in the group that received usual care. About the same number of people in each group died from cancer, settling a decades-old debate about the effectiveness of traditional annual screenings.

The study participants in each group - those who received annual screenings and those who went about receiving ordinary care - had a similar make up. Forty-two percent of the people in each group were former smokers, and 10 percent were current smokers.