 |
|
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Table 1. Effect of Screening Intervention on Reducing Mortality from Colorectal Cancera
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|
Fecal Occult Blood Test
|
Sigmoidoscopy
|
Digital Rectal Exam
|
|
aThere are no data on the effect of other screening interventions (i.e., fecal occult blood test combined with sigmoidoscopy, barium enema, colonoscopy, computed tomographic colonography, and stool DNA mutation tests) on mortality from colorectal cancer.
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Study Design
|
Randomized controlled trials |
Case-control studies, randomized controlled trials in progress |
Case-control studies |
|
Internal Validity
|
Good |
Fair |
Fair |
|
Consistency
|
Good |
Fair |
Good |
|
Magnitude of Effects
|
15%–33% |
About 50% for left colon |
No effect |
|
External Validity
|
Fair |
Poor |
Poor |
|
|
|
