Medical researchers have found that follow-up colonoscopy rates after a positive stool-based screening test result for colorectal cancer were lower than expected among an average-risk population. The research was funded by the Exact Sciences, maker of a molecular test for colon cancer taken at home, and published on Wednesday in JAMA Network Open.
The study makes a case for targeted intervention by clinicians and healthcare systems that might improve follow-up colonoscopy rates.
Colonoscopy is the most common colorectal cancer (CRC) screening procedure in the U.S. However, logistical challenges, such as bowel preparation, sedation, and transportation, may hinder colonoscopy completion rates. Non-colonoscopy screening options include less-invasive, more convenient at-home stool-based tests, such as fecal immunochemical tests that use antibodies to detect blood in the stool, and multitarget stool DNA tests that identify CRC-associated DNA biomarkers. Recently, particularly during the COVID-19 pandemic, at-home stool-based tests have had high utilization rates.
Although stool-based tests are a convenient alternative to colonoscopy for initial CRC screening, a follow-up colonoscopy is required to complete the screening following a positive result. Failed or delayed follow-up is associated with higher CRC risk and related complications. Despite this evidence, reported follow-up colonoscopy rates within community settings are low, ranging from 18% to 75% within 12 months of a positive stool-based test result, failing to achieve the full benefits of widespread at-home screening.
Researchers sought to identify the overall follow-up colonoscopy rates after a positive stool-based test result, and to assess the factors associated with follow-up colonoscopy rates, including the COVID-19 pandemic. Their study evaluated follow-up colonoscopy rates among a large national sample of U.S. patients with positive stool-based test results across different healthcare organizations and patient characteristics.
This cohort study included 32,769 individuals from 39 different healthcare organizations—all average-risk primary care patients aged 50 to 75 years with a positive stool-based test result between January 2017 and June 2020. The study included retrospective analysis of deidentified administrative claims and electronic health records data, and qualitative interviews with clinicians from five healthcare organizations.
Researchers found that follow-up colonoscopy rates after a positive stool-based test result for colorectal cancer screening were low among an average-risk population, with a median 53.4% follow-up colonoscopy rate across 39 healthcare organizations within one year. The follow-up colonoscopy rates were 43.3% within 90 days of the positive stool-based test result, 51.4% within 180 days, and 56.1% within 360 days. Clinicians interviewed uniformly expressed surprise at the low rates.
These rates were inconsistent across patient demographic categories, indicating potentially addressable health disparities. Socioeconomic factors, including race, ethnicity, insurance type, type of test, and health care organization, along with the COVID-19 pandemic, were associated with lower follow-up colonoscopy rates.
Targeted interventions by clinicians and healthcare systems to improve overall follow-up colonoscopy rates and to reduce the colonoscopy backlog resulting from the March to June 2020 peak pandemic months may help achieve the full clinical benefits from stool-based colorectal cancer screening tests. The researchers warn that long delays in follow-up colonoscopies after positive stool-based tests may lead to worse CRC outcomes.