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Ever had CT colonoscopy

Codes and Frequencies

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For sample adults aged 40 years or older, CTCOLEV indicates whether the respondent had ever had a CT colonography or virtual colonoscopy.

Related variables:

  • CTCOLLNO: Time since last CT colonoscopy: Number of units
  • CTCOLLTP: Time since last CT colonoscopy: Time period
  • CTCOLLDMO: Calendar month of last CT colonoscopy
  • CTCOLLDYR: Calendar year of last CT colonoscopy
  • CTCOLLESTY: Time since last CT colonoscopy: Grouped year estimate
  • CTCOLLGYRR1: Time since last CT colonoscopy: Grouped year recode 1 (2005 method)
  • CTCOLLGYRR2: Time since last CT colonoscopy: Grouped year recode 2 (2000 method)
  • CTCOLLY: Main reason for last CT colonoscopy

According to the survey form, the previous question was prefaced with:

CT colonography, sometimes called virtual colonoscopy, is a new type of test that looks for cancer in the colon. Unlike regular colonoscopies, you do not need medication to make you sleepy during the test. In this new test, your colon is filled with air and you are moved through a donut-shaped X-ray machine as you lie on your back and then your stomach.

According to the 2010 and forward Field Representative's Manual, this and related questions were asked: determine the practices and knowledge of the public with regard to cancer screening practices. This includes practices that are known to reduce mortality from cancer and some for which evidence of effectiveness is not available. The 2010 Cancer Screening Supplement will be the first time questions about having a breast MRI, virtual colonoscopy, and lung x-ray are in the NHIS.

The Manual in 2010 and forward further provided the following definition for cancer:

A term for diseases in which abnormal cells divide without control. Cancer cells can invade nearby tissue and can spread through the bloodstream and lymphatic system to other parts of the body.

The Manual in 2010 and forward also provided the following statement regarding how the data from the Cancer Screening questions would be used:

. . . It also allows for comparisons among subgroups of the population to examine factors that may influence . . . cancer screening exam practices. Together, this information will be useful in developing public health and health services programs to increase . . . the use of regular and effective screening.


There are no comparability issues.


  • 2010; 2015; 2018: Sample adults age 40+ who have ever heard of CT colonography or virtual colonoscopy.


  • 2010, 2015, 2018