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Figure 1. Analytic Framework and Key Questions (KQs) (Text Description)

Figure 1 depicts the analytic framework for this review. The text at left-hand side of the figure reads "Adults age ≥50 y, average risk" and arrows point from it to three circles labeled 1, 2, 3 to denote these Key Questions (KQs).

An arrow points from KQ1 to a text box that reads: "Decreased colorectal cancer mortality. Decreased all-cause mortality."

An arrow points from KQ2 to a series of text boxes that read:

Arrows point collectively from these boxes to three text boxes that read:

A line leads from "Colorectal cancer diagnosis" through a circle labeled 4 (Colorectal cancer treatment); the line then divides into two arrows that point to the text box that reads: "Decreased colorectal cancer mortality. Decreased all-cause mortality" and to a circle labeled 5. An arrow points from KQ5 to an oval that reads "Harms of treatment."

A line leads from "Adenomatous polyp removal" through a circle labeled 6 (Surveillance); the line then divides into two arrows that point to the text box that reads: "Decreased colorectal cancer incidence" and to a circle labeled 7. An arrow points from KQ7 to an oval that reads "Harms of surveillance."

A line leads from "Negative screening" through a circle labeled 8; the line then becomes an arrows that points back to KQ2.

An arrow points from KQ3 to a oval that reads: "Harms of screening."

Key Questions 1-3 are listed below the figure.

KQ1: What is the effectiveness of the following screening methods (alone or in combination) in reducing mortality from colorectal cancer? a. Flexible sigmoidoscopy, b. Colonoscopy, c. Computed tomographic (CT) colonography, d. Fecal screening tests: i. High-sensitivity guaiac fecal occult blood test (FOBTs); ii. Fecal immunochemical test; iii. Fecal DNA test.
KQ2a: What are the sensitivity and specificity of 1) colonoscopy and 2) flexible sigmoidoscopy when used to screen for colorectal cancer in the community practice setting?
KQ2b: What are the test performance characteristics of 1) CT colonography and 2) fecal screening tests (as listed in KQ1d) for colorectal cancer screening, as compared to an acceptable reference standard?
KQ3a: What are age-specific rates of harm from colonoscopy and flexible sigmoidoscopy in the community practice setting?
KQ3b: What are the adverse effects of newer tests, including 1) CT colonography and 2) fecal screening tests (as listed in KQ1d)?

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