Many patients who received a positive stool-based screening test result for colorectal cancer did not receive a follow-up colonoscopy within 1 year, according to the results of a mixed-methods cohort study.

Researchers also reported a decrease in follow-up colonoscopies during the early days of the COVID-19 pandemic, “suggesting a backlog of patients with positive [stool-based screening test (SBT)] results that must be addressed.”

SBTs are effective, noninvasive alternatives to colonoscopy, but a complete colorectal cancer screening paradigm requires patients with positive SBT results to undergo a timely follow-up colonoscopy (FU-CY), Jeff T. Mohl, PhD, director of research and analytics for the American Medical Group Association, and colleagues wrote in JAMA Network Open.

The researchers conducted a mixed-methods cohort study to assess FU-CY rates after a positive SBT result and to better understand how the pandemic affected FU-CY rates. They evaluated data from average-risk primary care patients at 39 health care organizations who were aged 50 to 75 years and had a positive SBT result between January 2017 and June 2020. The researchers included a retrospective analysis of electronic health records data and deidentified administrative claims between June 2015 and June 2021 from the Optum Labs Data Warehouse. They also conducted qualitative, semi-structured interviews with clinicians from five health care organizations.

Of the 32,769 participants included in the study, 88% were white, 51.7% were women and the mean age was 63.1 years.

Mohl and colleagues found that, within 90 days of a positive SBT result, FU-CY rates were 43.3%. Within 180 days, the rates were higher, at 51.4%, and within a year, the rates were 56.1%.

“This rate is far off the follow-up target of 80% recommended by the U.S. Multi-Society Task Force on CRC, and even the best performing [health care organizations] in our sample did not achieve this target,” the researchers wrote.

They noted that rates varied by race and ethnicity, insurance type and presence of comorbidities. Compared with white patients, FU-CY rates were significantly lower among Black patients (HR = 0.85; 95% CI, 0.8-0.91) and Asian patients (HR = 0.79; 95% CI, 0.69-0.91). In addition, patients with commercial insurance were more likely to have a FU-CY than Medicare beneficiaries (HR = 0.95; 95% CI, 0.91-0.99) and Medicaid beneficiaries (HR = 0.79, 95% CI, 0.73-0.85).

Overall FU-CY rates were particularly low in the first half of 2020, according to Mohl and colleagues. Only 44% of patients who had an index result in March 2020 received a FU-CY within 1 year compared with 55.9% among patients who had an index result in March 2019. However, there was no significant difference in FU-CY rates among patients with index results in June 2020 vs. June 2019, “suggesting that the initial stages of the pandemic were more disruptive than subsequent months,” the researchers wrote.

“In fact, patients who received a positive SBT result in June followed up at a higher overall rate than the 2019 average, though the absolute number of patients in this subpopulation was small,” they added.

The low rates were surprising to clinicians across the board.

“In the qualitative interviews, 100% of clinicians indicated that they were unaware of low FU-CY rates,” Mohl and colleagues wrote. “When asked about barriers to FU-CY, clinicians cited both patient discomfort (with colonoscopy preparation and procedure) and organizational barriers (eg, clinician not alerted to positive test result).

Mohl and colleagues concluded that their findings highlight “opportunities for targeted intervention by clinicians and health care systems.”

“Successful screening for CRC requires timely colonoscopy after positive SBTs,” they wrote. “A significant decline in completion of screening with FU-CY during the early COVID-19 pandemic warrants prioritizing screening backlogs, given that the long delays in follow-up care may lead to worse CRC outcomes.”

Perspective

Minhhuyen Nguyen, MD, AGAF, FACP

Increased screening rate has been a top priority of the U.S. Multi-Society Task Force on colorectal cancer using endoscopy and stool-based tests. A positive stool test requires an FU-CY. This study examines the rate of FU-CY across multiple health care systems from 2017 to 2020 and finds it wanting, about 56% within a year from the positive test, below the set goal of 80%. Racial, socioeconomic factors and history of comorbidities play a role in the lower rates. The COVID-19 pandemic also contributes to this depressed follow-up rate. Limited endoscopic resources and the COVID-19 backlog might prolong this problem.

There appear to be several ways to improve this problem:

1. all health care systems using EHR should routinely track FU-CY rates after positive stool tests, whether or not the colonoscopy is done within the system or in another location;
2. patient education can be enhanced at the time of the test order; and
3. a centralized patient navigation program and robust community outreach efforts can work together to track test results and arrange for follow-up colonoscopy.

Successful efforts would lead to better colorectal cancer outcomes and reduce health disparities in the long run.

Minhhuyen Nguyen, MD, AGAF, FACP

Professor, department of medicine, Fox Chase Cancer Center