The nationwide use of CT colonography is low but appears to be higher among individuals from an ethnic background compared with their White counterparts, according to the results of a cross-sectional survey by researchers in the US.
Globally, cancer of the colon and rectum (colorectal cancer) was diagnosed in 1.93 million people in 2020 and responsible for 916,000 deaths. Moreover, screening colonoscopy has been shown to be associated with a substantial decreased mortality risk.
CT colonography (CTC) is a minimally invasive test that uses CT scans to check the colon and rectum. In a 2008 study, the authors concluded that CTC screening identified 90% of subjects with adenomas or cancers measuring 10 mm or more in diameter and that the results augmented published data on the role of CTC in screening patients with an average risk of colorectal cancer. However, to date, there is limited information on the sociodemographic factors that might influence uptake of CTC.
For the present investigation, the researchers turned to the National Health Interview Survey (NHIS), which is a nationally representative cross-sectional survey and used data collected in 2019.
Included participants were aged 50 to 75 years of age and with no recorded history of colorectal cancer. In the NHIS survey, individuals were asked about whether or not they ever had a CTC and if they responded positively, when the scan had been performed.
The researchers collected additional information on age, gender, ethnicity and employment status. They employed multiple variable logistic regression to evaluate predictors of CTC use.
Predictors of CTC utilisation
A total of 13,709 individuals with a mean age of 61.4 years (52.7% female) were included in the analysis, of whom, 70.3% were White, 10.4% Black and 12.1% Hispanic.
In total, only 1.4% of participants reported having previously undergone CTC and, of these, 39.9% had the procedure within the last 12 months.
When analysing the association between CTC use and ethnicity, Hispanic individuals were more than twice as likely to undergo CTC compared with White participants (OR = 2.67, 95% CI 1.66 – 4.29, p < 0.001). There was also a similarly higher use among Black individuals (OR = 2.47, 95% CI 1.60 – 3.82, p < 0.001) than White participants.
Among the other sociodemographic factors examined, only participants who reported that they worked in the last week were significantly less likely to have a CTC (OR = 0.61, 95% CI 0.40 – 0.94, p = 0.024).
One limitation recognised by the authors was how the study data were collected in 2019 prior to the COVID-19 pandemic and therefore they were unable to assess any potential impact on CTC uptake. They concluded that strategies improving access to CTC services could mitigate the observed racial disparities.
O’Connor B et al. Predictors of CT Colonography Use: Results From the 2019 National Health Interview Cross-Sectional Survey J Am Coll Radiol 2022