No increase in colorectal cancer screening in 2019 after American Cancer Society recommends starting screening at age 45

In May 2018, the American Cancer Society (ACS) updated guidelines to recommend colorectal cancer (CRC) screening at age 45 years for persons at average risk.¹ Fedewa et al. reported that CRC screening participation among adults aged 45-49 years increased from 4.8% in early 2018 to 11.7% in late 2018, coincident with updated ACS guidelines.² It is unknown whether this initial increase persisted as guidelines were implemented. To address this gap, we examined trends in CRC screening participation through 2019 in a nationally representative sample.

We used data from the National Health Interview Survey (NHIS), an annual in-person survey of U.S. households covering a range of health topics.³ NHIS allows for nationally representative estimates, including of underrepresented groups, by using a multi-stage clustered probability design and accounting for non-response. We used data from survey years 2015, 2018, and 2019 (when CRC screening participation was measured) to identify participants aged 45-59 years. Response rates ranged from 53.1% in 2018 to 59.1% in 2019, and the total number of participants ranged from 5,809 to 7,723. We excluded participants with a history of CRC (n=86) or with missing information on CRC screening participation (ranging from n=63 for colonoscopy in 2019 to n=740 for stool-based tests in 2015). The final sample included 20,967 participants.

We examined two outcomes: 1) past-year CRC screening, defined as colonoscopy, flexible sigmoidoscopy, computed tomography (CT) colonography, FIT-DNA (measured in 2018 and 2019), or stool-based test within the past 12 months;² and 2) up-to-date CRC screening, defined as colonoscopy within the past 10 years, flexible sigmoidoscopy or CT colonography within the past 5 years, FIT-DNA test within the past 3 years, or stool-based test within the past year. We estimated prevalence of outcomes for respondents aged 45-49 years in each interview quarter (Q1: January-March, Q2: April-June, Q3: July-September, and Q4: October-December). We also estimated prevalence in respondents aged 50-54 and 55-59 years. Analyses were conducted using SAS 9.4 (SAS Institute, Cary, NC), with weights, strata, and primary sampling units accounting for the complex survey design.

Characteristics of the study population are summarized in Supplementary Table 1. Past-year CRC screening increased from 6.6% in 2015 to 7.6% in 2018 and subsequently decreased to 6.4% in 2019 (p=0.40) for the 45-49-year age group. This pattern was similar by interview quarter (Figure 1A). For example, past-year CRC screening increased across quarters in 2018 (4.5%, 6.2%, 8.1%, and 11.5%, p-for-trend<0.01) but remained similar in each quarter in 2019 (8.8%, 4.1%, 5.9%, and 6.8%, p-for-trend=0.48). Up-to-date CRC screening increased from 18.4% in 2015 to 20.3% in 2018 to 20.5% in 2019 although fluctuated by quarter (Figure 1B)

Figure 1.

Past-year (A) and up-to-date (B) colorectal cancer screening among adults 45 to 59 years, 2018- 2019

Past-year and up-to-date CRC screening for ages 50-54 and 55-59 years are shown in Figure 1. For the 50-54-year age group, both past-year and up-to-date screening were similar across quarters from 2015 to 2019 – about 18.5% completed screening in the past year and 46% were up-to-date with screening. Up-to-date screening increased for the 55-59-year age group, from 60.9% in 2015 to 65.1% in 2019, but with no appreciable trend by quarter. Past-year screening ranged from 16.0% in Q2 of 2015 to 21.4% in Q2 of 2018.

Hence, in a nationally representative sample of adults aged 45-49 years, past-year CRC screening increased in 2018, in concert with updated ACS guidelines recommending screening begin at age 45 years. This initial increase did not persist through 2019, and there was no appreciable increase in screening for the two older age groups (50-54 and 55-59 years).

The increase in CRC screening participation among adults aged 45-49 years in 2018 is likely related to revised ACS guidelines and increased awareness of early-onset CRC due to accompanying media attention.^{4, 5} By 2019, however, screening participation returned to what it was prior to revised guidelines. Public attention may have waned, or the new guidelines may have disproportionately benefited the worried well.⁶Only a few states (e.g., Georgia, Illinois) mandate coverage for CRC screening according to ACS guidelines, and it is also possible that many younger adults in 2019 may not have had sufficient insurance coverage.

In addition to increased screening in the 45-49-year age group, some have suggested a “spillover” effect, whereby expanding screening eligibility to 45-49-year-olds would also prompt older adults who are overdue to complete CRC screening.⁷ However, we did not observe any notable increases in past-year or up-to-date CRC screening for 50-54- and 55-59-year-olds from 2015 to 2019.

In 2021, the U.S. Preventive Service Taskforce (USPSTF) revised its guidelines to also recommend average-risk CRC screening starting at age 45 years.⁸ While commercial payers, Medicare, and Medicaid are required to cover USPSTF recommendations (grade A or B), implementation can take many years.³ The pattern of screening we observed among younger adults before and after revised ACS guidelines may offer some insight into what to expect as the new USPSTF guidelines are implemented. Specifically, low screening participation in both the 45-49- and 50-54-year age groups suggest increases in screening cannot be expected with new guidelines alone. Test preferences (e.g., colonoscopy vs. stool-based test), barriers to screening (e.g., time off work), and perceived risks and benefits, which likely differ between younger and older adults, should be considered and targeted by interventions specific to this age group.

An important strength of our study is the nationally representative sample. We extend the prior work of Fedewa et al. to examine CRC screening participation through 2019.²

In summary, there was no increase in CRC screening participation after the ACS updated guidelines in 2018, raising concerns as new USPSTF guidelines are implemented. Additional research is needed to: 1) identify screening preferences, barriers, and perceptions unique to younger adults, and 2) adapt evidence-based interventions to increase screening participation in this age group.