Outreach Efforts to Improve CRC Screening Rates Fall Short

Pam Harrison

September 05, 2017

Efforts to improve the uptake of either fecal immunochemical testing (FIT) or colonoscopy to detect asymptomatic colorectal cancer (CRC) among average-risk but screening-averse patients can work, but they nevertheless fall short of convincing the majority of patients that they should undergo either type of screening, two studies suggest.

Both studies were published online September 5 in JAMA.

"Screening rates for CRC in the United States are inadequate [and] creative approaches are necessary to improve them," Michael Pignone, MD, MPH, University of Texas, Austin, and David Miller Jr, MD, Wake Forest School of Medicine, Winston-Salem, North Carolina, comment in an accompanying editorial.

"Helping patients identify the test to which they are most likely to adhere over time and then helping them follow through is likely to yield the greatest benefit," they add.

FIT vs Colonoscopy Outreach

One study compared an FIT outreach program with a colonoscopy outreach program in improving screening uptake. Amit Singal, MD, University of Texas Southwestern, Dallas, and colleagues mailed an FIT outreach kit to 2400 patients in a publicly funded safety-net health system and a colonoscopy package to another 2400 patients in the same health system. An additional 1199 patients, who received usual care with clinic-based screening, served as controls.

Patients were aged 50 to 64 years. All had visited a primary care physician in the year prior to study enrollment. For study enrollment, participants had to be remiss in following CRC screening recommendations.

Individuals in both outreach groups received a letter inviting them to participate in the respective programs, but FIT participants received a one-sample FIT test kit along with postage-paid return envelopes; one envelope was to be sent back every 12 months during the 3-year study. Participants in the colonoscopy outreach group received a telephone number to schedule a colonoscopy. Once they had scheduled a colonoscopy, participants were mailed a free bowel prep kit along with instructions.

Up to two attempts were made by research staff to encourage patients to participate in each of the respective outreach programs.

"Usual care group participants were eligible to receive whatever visit-based screening was recommended and ordered during any in-person outpatient visit," the investigators observe.

The study authors regarded the screening process as complete if one of the following conditions were met: the participant underwent colonoscopy and no cancer was detected; cancer was detected on colonoscopy and the patient was evaluated for treatment within 2 months or less; the patient received a normal FIT result and FIT was repeated every years for the 3-year study interval; the patient received an abnormal FIT result and subsequently underwent colonoscopy within 6 months or less if no cancer was detected, or the patient received an abnormal FIT test result, a cancer was detected on colonoscopy, and the patient was evaluated for treatment within 2 months or less following cancer detection.

On the basis of this collective definition, 38.4% of patients in the colonoscopy outreach group completed the screening process within 3 years; 28% of those in the FIT outreach group completed the screening process; and 10.7% of those in the usual care group completed the screening process.

Detection rates of adenomas and advanced neoplasms were highest in the colonoscopy outreach group. They slightly higher in the FIT outreach group than in the usual-care group.

Table. Between-Group Differences

  Colonoscopy Outreach vs Usual Care P Value FIT Outreach vs Usual Care P Value Colonoscopy Outreach vs FIT Outreach P Value
Screening process completion 27.7% <.001 17.3% <.001 10.4% <.001
Detection rate for adenoma 10.3% <.001 1.3% .08 9.0% <.001
Detection rate for advanced neoplasia 3.1% <.001 0.7% .13 2.4% <.001


Screening Process Failures

Dr Singal and colleagues note that 44% of participants in the colonoscopy outreach group failed to initiate screening, as did 30.2% of those assigned to the FIT outreach group.

More than a third of the FIT outreach participants also failed to undergo repeat FIT testing for each of the 3 years they were required to do so. Of those with an abnormal FIT test result, almost two thirds did not follow through with a timely colonoscopy.

Participation was even less optimal in those assigned to the usual-care group: 58.1% failed to initiate screening, and more than one quarter utilized the FIT test only intermittently. Some 80% of the same group also did not undergo colonoscopy in the required time frame following an abnormal FIT test result.

"Both mailed outreach interventions encouraging FIT and encouraging colonoscopy increased the proportion of individuals who completed the CRC screening process within 3 years compared with usual care," the study authors conclude.

"However, screening process completion for both outreach groups remained below 40%, highlighting the potential for further improvement," they add.

French RCT

The other study was a randomized controlled trial conducted by Cedric Rat, MD, PhD, French National Institute of Health and Medical Research, Nantes, France, and colleagues. They provided a group of general practitioners (GPs) on the west coast of France with either a specific list of patients who were overdue for CRC screening or information on the general rate of CRC screening in their region ― a so-called "generic reminder list." Results were compared to those of patients in a usual-care group.

Unlike in the United States, in France, asymptomatic patients aged 50 and 74 years are mailed a letter to consult with their GP to undergo an initial FIT test first; if that test is positive, the GP will then refer the patient to a gastroenterologist for a colonoscopy.

In France, colonoscopy is reserved for symptomatic or high-risk patients, as determined on the basis of family history.

A total of 1446 GPs completed the study. Roughly equal numbers of GPs were randomly assigned to the patient-specific reminders group, the generic reminders group, and the usual-care group. A total of 31,229 patients (mean age, 60.9 years) completed the 1-year study. All the patients were at average risk for CRC but had not completed FIT testing within 3 months of having received their first invitation for CRC screening.

At 1 year, a mean of 24.8% of patients per GP who had received the patient-specific reminders list had undergone the FIT screening test.

This was 4.2% higher than for patients whose GPs had been assigned to the usual-care group, the investigators observe.

Among GPs who had been assigned to the generic reminders group, a mean of 21.7% of patients per GP had participated in the FIT screening test at 1 year, a difference that was not significant from a mean of 20.6% of patients per GP in the usual-care group.

"The target of this large randomized clinical trial (RCT) was the GP rather than the patient," Dr Rat comments.

"[We found that] providing French GPs caring for adults at average risk of CRC with a list of their patients who were not up-to-date with their CRC screening results in a small but significant increase in patient participation in FIT screening at 1 year compared with patients who received usual care," they conclude.

Missed Opportunity

The editorialists point out that if more than 80% of adults eligible to be screened for CRC took advantage of some form of screening, an estimated 200,000 deaths in the Unites States could be prevented in less than 20 years.

However, only about one third of adults who are eligible for CRC screening are screened, and rates of screening vary considerably by ethnicity, income and, education, they add.

None of the authors of either study have disclosed any relevant financial relationships. Dr Pignone has served as a medical editor for Healthwise, a nonprofit developer of patient decision aids. Dr Miller has disclosed no relevant financial relationships.

JAMA. Published online September 5, 2017. Study 1 abstract, Study 2 abstract, Editorial


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