FIT Completion, Yield Rates in CRC Screening Similar After New Screening Guidelines

The updated screening guidelines from the US Preventive Services Task Force (USPSTF) that encouraged colorectal cancer (CRC) screening initiation at the age of 45 years in all patients should not affect the completion and yield rates of the fecal immunochemical test (FIT), according to a study published in Annals of Internal Medicine.¹ These results support the new guidelines, as screening completion is of paramount importance in detecting CRC.

The USPSTF in 2021 modified the guidelines regarding screening for CRC,² changing the recommended age to start screening from 50 years to 45 years, as prevalence of CRC has increased in patients aged 45 to 49 years. However, there is a lack of data regarding the completion of screening in these patients and the demographics of those who do complete screening for CRC in this age group. This study aimed to access the completion, positivity, and follow-up after a positive result of patients using the FIT method of screening for CRC in patients aged 45 to 49 years compared with those aged 50 years.

The Kaiser Permanente locations in Northern California (KPNC), Washington (KPWA), and Colorado (KPCO) were used to conduct the study and whose data were included in the final study. All patients included in the study had insurance, with all patients living in suburban, urban, and semirural areas of Northern California; Washington and Idaho in the Washington location; and the greater Denver, Boulder, and Colorado Springs metropolitan areas in the Colorado location.

KPNC and KPWA both mailed FIT kits to patients in their area after a primer letter notified them of the FIT kit’s arrival. KPNC provided reminders through robocalls, letters, and telephone calls as needed whereas KPWA used text reminders and mailed letters, with both locations offering a FIT kit during office visits. KPCO used text message to inform patients about the FIT test arriving and used text messages and mailed letters as reminders.

Patients were eligible for the study if they were aged 45 to 50 years in 2022 and had a documented FIT kit distribution between January and September of that year. Patients with inflammatory bowel disease, a history of CRC, or prior lower gastrointestinal surgery were excluded from the study. FIT completion within 3 months, positive results from the FIT test, completion of a follow-up colonoscopy, false positive results, and findings at the follow-up colonoscopy all acted as primary outcomes. Electronic health records were used to collect demographic data and health records for all patients.

There were 267,732 patients included in this study, of whom 79.9% were aged 45 to 49 years. A total of 80.7% of the patients were from KPNC, with 9.7% from KPWA and 9.5% from KPCO. Just over half were female (50.5%) and most were White (39.5%), Hispanic (22.3%), or Asian (21.2%), with Black patients making up 4.6% of the population.

Patients aged 45 to 49 years had a slightly higher completion of FIT compared with patients aged 50 years (38.9% vs 37.5%; adjusted risk ratio [aRR], 1.05; 95% CI, 1.04-1.06). Overall, both male (37.3% vs 35.7%; aRR, 1.06; 95% CI, 1.04-1.08) and female (40.4% vs 39.4%; aRR, 1.04; 95% CI, 1.03-1.06) patients had this observed result. Patients of “other” race were the only group that had a lower completion of FIT in patients aged 45 to 49 years (28.0% vs 36.3%).

Patients aged 45 to 49 years had slightly higher completion of FIT kits compared with patients aged 50 years | Image credit: Paul Maguire - stock.adobe.com

Patients aged 45 to 49 years were more likely to complete FIT compared with patients aged 50 years at KPNC (40.5% vs 37.6%; aRR, 1.08; 95% CI, 1.07-1.10) whereas completion was similar at KPWA (34.5% vs 34.0%; aRR, 1.01; 95% CI, 0.96-1.06) and patients aged 45 to 49 years were less likely to complete FIT at KPCO (30.7% vs 40.2%; aRR, 0.77; 95% CI, 0.73-0.80).

FIT positivity was lower in patients aged 45 to 49 years overall (3.6% vs 4.0%; aRR, 0.91; 95% CI, 0.84-0.98). Similar rates of a follow-up colonoscopy were also found between the groups (64.9% vs 67.4%; aRR, 1.00; 95% CI, 0.94-1.05). Adenomas were detected less frequently in patients aged 45 to 49 years (58.8% vs 67.7%; aRR, 0.88; 95% CI, 0.83-0.95).

There were some limitations to this study. The results may not be generalizable, as the health care system used was exclusively Kaiser Permanente. Higher completion rates may have been found with longer parameters for FIT completion and colonoscopy completion. Polyp size and adenoma count were not available. Risk ratio estimates were uncertain due to the low absolute number of events. This study was also not meant to directly compare strategies of starting screening at the age of 45 years compared with 50 years.

The researchers concluded that the finding that patients aged 45 to 49 years completed FIT kits at a similar rate to those aged 50 years supports the recommendations to start screening for CRC in this age group, as it can help with detection of CRC.

References

1. Levin TR, Jensen CD, Udaltsova N, et al. Colorectal cancer screening completion and yield in patients aged 45 to 50 years. Ann Intern Med. Published online October 22, 2024. doi:10.7326/M24-0743
2. Colorectal cancer: screening. US Preventive Services Task Force. May 18, 2021. Accessed October 22, 2024. https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/colorectal-cancer-screening