Multitarget Stool DNA Tests Often Not Completed

TOPLINE:

An analysis from a large healthcare system shows that nearly half of those prescribed multitarget stool DNA (mt-sDNA) tests for colorectal cancer (CRC) do not complete them, underlining the need for strategies to improve these rates in certain populations.

METHODOLOGY:

• Researchers conducted a retrospective cohort study of 91,664 mt-sDNA orders for 73,704 patients, placed from 2017 to 2021 within the University of Pittsburgh Medical Center system.
• They analyzed data collected from electronic medical records, including patient age, sex, and race, as well as test completion (patient returned the stool specimen) and outcomes (positive, negative, or unable to process).
• Where possible, results were validated against records from Exact Sciences, the mt-sDNA test manufacturer.

TAKEAWAY:

• Only 54.7% of patients completed mt-sDNA testing, with similar completion rates in men (52.7%) and women (53.3%).
• Test completion rates declined substantially with repeat mt-sDNA orders, reaching just 32% for patients with three or more test orders.
• By age, completion rates were 48.2% in those aged less than 50 to 59 years, 56.3% in those aged 60-69 years, and 55.6% in those aged 70 years or more.
• Completion rates were higher for White (54.1%) and Asian (56.9%) patients than for Black patients (38.8%).
• Overall, 18.6% of the completed tests were positive. Test positivity increased with age: 12.4% in patients aged less than 50 years, 19.3% in those aged 60-69 years, and 24.4% in those aged 70 years or more. Unexpectedly, Black patients had a lower positivity rate (12.7%) than White patients (18.8%).

IN PRACTICE:

“Better understanding of the reasons for lower compliance and interventions to improve compliance in Black patients are needed,” the authors concluded. “Additional measures to encourage compliance among Black patients may be required, and practitioners may need to provide additional facilitation to enhance compliance.”

SOURCE:

The study, with first author Linda Jiang, MD, Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, was published online in The American Journal of Gastroenterology.

LIMITATIONS:

The study was retrospective, limiting insights into factors that went into the selection of mt-sDNA testing for CRC screening, the reasons for repeat test orders, and patient factors associated with completion or noncompletion of tests, as well as test positivity. The results may not fully account for patients who changed providers or healthcare systems during the study period.

DISCLOSURES:

The study was supported by the National Institutes, the Piatt Family, the Mylan Foundation, and an unrestricted grant from Exact Sciences. One author reported research support from Exact Sciences and other mt-SDNA test manufacturers.