Mailed FIT Outreach Boosts CRC Screening, but Gains Are Not Sustained

A centralized mailed fecal immunochemical test (FIT) outreach program increased colorectal cancer (CRC) screening rates at federally qualified health centers (FQHCs) compared with usual care for 2 years, but the difference was no longer statistically significant by year 3, according to a cluster randomized clinical trial published in JAMA Network Open.¹

The findings underscore the challenges of sustaining gains in resource-strained safety net settings.

Addressing CRC Screening Gaps in Underserved Populations

CRC is the second leading cause of cancer death in the US. Black and American Indian or Alaska Native individuals face higher mortality rates than non-Hispanic White individuals, with several racial and ethnic groups more likely to be diagnosed at a later stage. Screening reduces both incidence and mortality, yet participation remains low among low-income and minoritized populations, many of whom receive primary care at FQHCs.

Mailed FIT outreach has a strong track record in these settings, with meta-analyses reporting screening increases of 22% to 28% over usual care. For example, a 2024 trial in North Carolina FQHCs found that centralized mailed FIT plus navigation raised 6-month screening completion by 20.3 percentage points.² A similar approach that paired mailed FIT with patient navigation increased screening among rural Medicaid enrollees in Oregon, though by a smaller margin of 7.3 percentage points.³

The current study, part of the San Diego Accelerating Colorectal Cancer Screening and Follow-Up Through Implementation Science program, tested whether a regional hub could keep screening rates elevated over multiple annual rounds.¹ Health Quality Partners of Southern California, a nonprofit hub, ran outreach on behalf of 16 clinics in 2 FQHC systems in San Diego County between June 2021 and May 2024.

Clinics were randomly assigned to usual care or annual outreach, which included an educational primer, a mailed FIT kit with prepaid return postage, and automated phone and text reminders, all in both English and Spanish. Rather than tracking only overdue patients, the researchers measured the share of all eligible patients aged 50 to 75 years who were up to date with any CRC screening.

The primary outcome was the proportion of patients up to date with any CRC screening after 3 years of intervention, with screening at 2 years considered a secondary outcome.

How Screening Rates Shifted Over 3 Years

The trial included 20,250 patients, 8334 of whom received care at 6 intervention clinics and 11,916 at 10 usual care clinics. Approximately 62% of patients in each group were insured through Medicaid, and Hispanic patients made up 28.7% of the intervention group and 38.9% of the usual care group.

Screening reached 39.0% (95% CI, 35.2%-42.9%) in intervention clinics vs 27.8% (95% CI, 24.5%-31.3%) in usual care clinics at year 1, a difference of 11.2 percentage points. The gap narrowed slightly at year 2 to 10.8 percentage points (37.8% [95% CI, 35.2%-40.4%] vs 27.0% [95% CI, 21.8%-32.9%]); both differences were statistically significant.

By contrast, at year 3, 39.4% (95% CI, 36.3%-42.6%) of patients in intervention clinics were up to date with screening compared with 36.5% (95% CI, 31.2%-42.2%) in usual care clinics. The 2.9–percentage point difference was not statistically significant (95% CI, −3.2 to 9.0).

How the Pandemic and Outreach Timing Shaped Results

Much of that early gap reflected a drop in screening at usual care clinics during the COVID-19 pandemic. Screening in intervention clinics held roughly steady at baseline levels throughout the study, whereas usual care clinics fell 12.9 percentage points from baseline by year 2 before rebounding by year 3. The researchers suggested that mailed outreach may have helped buffer pandemic-era declines in screening.

Implementation problems also likely shaped the year 3 result, the researchers added. Pandemic-related delays shortened the grant-funded follow-up period, so the year 3 data query to identify eligible patients ran about 2 months before the observation window opened rather than at the planned 1-year interval. As a result, some patients who had completed a FIT in response to earlier outreach were not yet due for repeat testing and were not invited in that cycle. In addition, both arms saw background co-interventions, including clinic pilots of multitarget stool DNA testing and a one-time hub text message encouraging all overdue patients to request screening.

Limitations Point to Need for Sustained Support

At the same time, the researchers acknowledged several limitations, including 2 FQHC systems discontinuing participation; 1 withdrew before intervention implementation, and the other exited after the first year. The trial also ran during 2 pandemic waves, making it difficult to separate intervention effects from broader disruptions.

Overall, the trial showed that centralized mailed FIT outreach improved CRC screening in FQHCs at 2 years but not at 3 years. With that in mind, the researchers stressed the need for strategies to maintain intervention fidelity and support long-term implementation to “maximize impact over time.”

“These results support continued evaluation of centralized outreach to promote sustained screening engagement in resource-constrained settings,” they concluded.

References

1. Martinez ME, Roesch S, Largaespada V, et al. Fecal immunochemical test outreach for colorectal cancer screening in community health centers: a randomized clinical trial. JAMA Netw Open. 2026;9(10):e2639013. doi:10.1001/jamanetworkopen.2026.39013
2. Reuland DS, O'Leary MC, Crockett SD, et al. Centralized colorectal cancer screening outreach in federally qualified health centers: a randomized clinical trial. JAMA Netw Open. 2024;7(11):e2446693. doi:10.1001/jamanetworkopen.2024.46693
3. Steinzor P. Mailed FIT outreach boosts CRC screening in Medicaid patients, study finds. AJMC. April 8, 2025. Accessed November 5, 2026. https://www.ajmc.com/view/mailed-fit-outreach-boosts-crc-screening-in-medicaid-patients-study-finds