TUESDAY, Aug. 5, 2025 (HealthDay News) -- Just under half of patients receiving an abnormal blood-based colorectal cancer screening test result receive a follow-up colonoscopy (FU-CY) within six months, according to a study published online July 29 in Gastroenterology.Timothy A. Zaki, M.D., from the University of California, Los Angeles (UCLA), and colleagues analyzed closed claims data to determine the FU-CY rate after an abnormal blood-based test result and identified predictors of FU-CY using national data. The analysis included 6,068 individuals who underwent a commercially available, blood-based colorectal cancer screening test (Shield, Guardant Health) with linked administrative data.The researchers found that 7.4 percent of individuals had an abnormal result. Of the 228 individuals with at least six months of follow-up, 49 percent received an FU-CY within six months (mean time to FU-CY, 66.4 days). At any time, 128 individuals (56 percent) received an FU-CY (mean time to FU-CY, 98.3 days overall). Individuals with Medicare Advantage (adjusted odds ratio [aOR], 0.26) were less likely to undergo FU-CY within six months versus those with private insurance. FU-CY at six months was also associated with having fewer comorbidities (aOR, 0.90). Age, race/ethnicity, and U.S. census region were not significant predictors of FU-CY within six months."Blood-based colorectal cancer screening is promising, but it only works if individuals complete the follow-up colonoscopy," senior author Folasade May, M.D., Ph.D., also from UCLA, said in a statement. "More efforts are needed to help patients follow through to actually diagnose and treat the disease."Several authors disclosed ties to relevant organizations.Abstract/Full Text (subscription or payment may be required).Sign up for our weekly HealthDay newsletter