In people examined between 1995 and 1998, the researchers found that three factors increased the probability of finding advanced growths in the upper part of the colon. These factors were older age, male sex, and certain types and sizes of polyps in the lower part of the colon. Using these factors, the researchers scored risk for advanced growths in the upper colon as low (0 to 1 point), intermediate (2 to 3 points), and high (4 to 7 points). The risk index worked in the second group of people examined between 1999 and 2001. Advanced growths in the upper part of the colon were found in 0.4%, 1.9%, and 3.8% of those classified as low, intermediate, and high risk, respectively.