Stool-based testing is a cornerstone of noninvasive colorectal cancer screening, yet its effectiveness depends entirely on regular, repeated participation over time. In this interview, Ethan Halm, MD, MPH, MBA, Vice Chancellor for Population Health at Rutgers University, sits down with Jasmin Hundal, MD, MS, MPH, to discuss findings from his team’s 10-year National Cancer Institute–funded study evaluating longitudinal adherence to annual fecal immunochemical testing (FIT) among more than 500,000 individuals across four major US health systems. He explores how proactive population outreach drives consistent retesting, reduces advanced-stage cancer presentations, and reshapes healthcare delivery.

Health System Infrastructure Drives Longitudinal Screening Adherence

While individual patient characteristics influence health-seeking behaviors, the study revealed that the overarching health system was the single strongest predictor of consistent annual retesting, demonstrating a more than 20-fold difference in adherence odds between sites. This variation was driven primarily by differences in proactive, centralized population health outreach rather than physician-level reminders alone.

Explaining the operational continuum among participating health systems, Dr. Halm noted that Kaiser Permanente Northern California achieved the highest adherence rates through an organized, multi-decade outreach infrastructure, explaining, “they adopted a FIT-first strategy unless there were extenuating circumstances; they would look in a continuous way at who was not up to date with screening, and they would proactively mail a FIT home stool test to people. They weren't waiting for people to come in to see the doctor.”

In addition to mailing tests directly, high-performing systems made kits available at pharmacies, clinical laboratories, and influenza vaccination clinics. Over time, completing tests repeatedly established a self-reinforcing routine, with Dr. Halm observing that “one of the other multivariable predictors of consistent FIT adherence was having done a prior test.” This repeated engagement helped patients overcome initial hesitations and integrated screening into regular preventive care, much like annual mammography.

Consistent Retesting and the Detection of Early-Stage Disease

Evaluating longitudinal outcomes across a 10-year horizon enabled investigators to measure the downstream oncologic impact of sustained retesting versus incomplete participation. The observational cohort confirmed that individuals who underwent consistent annual screening had a significantly higher proportion of localized disease and fewer advanced-stage presentations. Emphasizing the clinical significance of these findings, Dr. Halm explained, “with this large observational study, we found that people who are consistent repeaters, versus never-repeaters or people who were the one-and-done folks, had a lower rate of distant disease. And that's really the most important thing, because we know that if we catch colorectal cancer early, we're much more likely to be able to treat it for cure.”

While all participating health systems utilized electronic health record (EHR) reminders when patients were overdue for screening, electronic alerts alone proved insufficient to achieve sustained testing across successive years. The proactive population-level delivery of screening kits ensured that eligible individuals were screened regardless of whether they scheduled routine outpatient appointments.

Implementation Strategies and the Evolution of Quality Metrics

As screening guidelines recommend initiating average-risk evaluations at age 45, overcoming inertia among younger cohorts requires removing logistical friction. Digital patient portal messages can prompt action, but physical delivery directly to the home remains a decisive differentiator in closing screening gaps. Reflecting on scalable implementation models, Dr. Halm stated, “the EHR nudges are necessary but not sufficient, because all these health systems use the same EHR and all have the same reminders. It's really having a proactive population health system that reaches out to patient, meets them where they are, and mails them FIT kits if they’re overdue.” He added that while an electronic notification is easily overlooked, “having something show up at people's doorstep really lowers the barrier to just doing it.”

These findings suggest that national quality frameworks must evolve beyond cross-sectional snapshots. Current public reporting mechanisms predominantly assess whether an individual has undergone screening at a single point in time, overlooking the necessity of sustained longitudinal participation and prompt diagnostic colonoscopy following abnormal findings. Addressing this paradigm, Dr. Halm noted, “all of the national quality metrics for breast, colon, cervical, and lung cancer just look at, are you screened up to date at one point in time?” Moving forward, he emphasized, “it's not enough to just do a test. You want to know if people are following up on the positive tests. One of the national quality metrics for 2027 will be rates of following up on positive stool tests, either FIT or Cologuard.”

As noninvasive screening incorporates multitarget stool DNA and emerging blood-based assays, maintaining high adherence and reliable diagnostic follow-up will remain vital to translating screening efficacy into reduced population mortality. For clinicians advising patients who choose the annual FIT option, Dr. Halm reiterated, “you've got to check your rear every year. It's not just a one-and-done test.

Conclusion

Annual stool-based screening offers an accessible, noninvasive pathway to reduce colorectal cancer mortality, but its clinical benefit depends on consistent, multi-year participation. As large-scale real-world data demonstrate, passive reliance on office visits and EHR alerts is insufficient to maintain regular screening. Healthcare organizations must transition toward centralized, proactive outreach strategies that deliver screening kits directly to patients and systematically track diagnostic follow-up for abnormal results. Shifting national quality metrics toward measuring longitudinal adherence will ensure that noninvasive modalities fulfill their preventive potential.

Key Takeaways

Health system design and proactive outreach infrastructure are the strongest predictors of longitudinal FIT screening adherence, producing more than a 20-fold variation across institutions.
Consistent repeat annual testing with FIT significantly reduces the incidence of advanced-stage, distant colorectal cancer compared with sporadic or single-round screening.
Electronic health record reminders and portal messages are necessary but insufficient; proactively mailing test kits directly to homes substantially lowers participation barriers.
Completing an initial screening test strongly predicts future adherence, establishing routine preventive care behaviors similar to regular mammography.
Quality programs should shift from measuring cross-sectional screening status to evaluating longitudinal adherence and timely diagnostic follow-up of abnormal results.

About the Speakers

Jasmin Hundal, MD, MS, MPH, is a second-year Hematology/Oncology Fellow at the Cleveland Clinic in Cleveland, Ohio. Previously, she completed her Internal Medicine Residency at the University of Connecticut. Dr. Hundal’s main area of interest is the overlap between cardiometabolic health and cancer, particularly for breast cancer patients and survivors. Outside of work, she enjoys traveling, cooking, and hiking.

Ethan Halm, MD, MPH, MBA, is a Professor of Medicine and the Vice Chancellor for Population Health at Rutgers Biomedical and Health Sciences. In this role, he strives to advance population health initiatives relating to research, education, and clinical care across Rutgers Health. Dr. Halm also serves as the Deputy Chief Population Health Officer for the RWJBarnabas Health System, the leading academic health system in New Jersey. He is also a core member of Rutgers institute for Health, Health Care Policy and Aging Research. His research focuses on understanding patient, provider, and system factors that impact care outcomes for individuals and populations.

Closing the Gap in Colorectal Cancer Screening Adherence