Figure 1.

Colonoscopies according to clinical indication. The clinical indication for each of the 25,635 preventative maintenance colonoscopies was ascertained. The indications were classified into average risk screening, elevated risk screening, and surveillance examinations. Average risk screening was defined as a person who did not have symptoms, or had a family history of colorectal cancer in only one first-degree relative older than 60 years of age. Elevated risk screening was defined as an asymptomatic person who had a family history of one first-degree relative diagnosed with colorectal cancer at age 60 years or younger or who had two first-degree relatives diagnosed with colorectal cancer at any age.