Who Is Reached With Clinic In-Reach and Outreach Strategies to Promote Colorectal Cancer Screening?

Screening for colorectal cancer (CRC) reduces CRC-associated incidence and mortality, yet it remains underutilized. These screening rates are especially low among Latinos in the United States (http://bit.ly/2vmAgHk). Although several clinic-based strategies have proven effective at increasing CRC screening rates in the general population, we know little about the comparative effectiveness of proven strategies to promote screening in the Latino population.

In this issue of AJPH, Castañeda et al. (p. 587) present findings from a direct comparison of two clinic-based approaches to increase CRC screening rates among Latino adults: clinic in-reach through one-on-one education versus clinic outreach through mailed fecal immunochemical tests (FITs). Clinic in-reach involves delivering a health-promotion program or clinical service to individuals who go to clinics for health care services. Outreach, on the other hand, extends beyond the clinic walls and provides services to those who might not otherwise be able to access those services directly at a clinical site. The basic difference between these approaches lies in the answer to the question “Who is reached?” Put simply, in-reach reaches those inside the clinic—who often have access to transportation, can take time away from work or family obligations, and may be experiencing an acute health issue. Outreach, on the other hand, reaches those outside the clinic—who have a valid address or telephone number and may be unable or unwilling to visit the clinic.

Given this distinction, I applaud the study of Castañeda et al. for what it tells us about reach. Specifically, their clinical trial in a federally qualified health center near the California–Mexico border showed that mailing fecal tests to individuals who are overdue for screening (mailed FIT outreach) led to higher rates of CRC screening than did a 10-minute one-on-one scripted education session delivered to individuals who attended their scheduled in-clinic visit (clinic in-reach). Their findings support the extant body of literature, including the findings of three recent systematic reviews^1–3 that demonstrate the effectiveness of mailed FIT outreach. These have reported absolute increases ranging from 21 to 28 percentage points and comparatively lower absolute increases for visit-based FIT distribution (15.9 percentage points). The findings of Castañeda et al. further show that combining the two strategies led to no further improvements in CRC screening uptake over mailed FIT outreach alone (78.9% vs 77.2%). Despite this study’s evidence and resounding endorsement of mailed FIT outreach over one-on-one education in-reach, we should not disregard in-reach strategies. The basis for this reasoning lies in the per-protocol findings of Casteñeda et al. (Table 1).

TABLE 1—

Comparisons of Per-Protocol and Intention-to-Screen Effectiveness: United States, 2015–2018

Protocol	Reach, % (No./Total No.)	Per-Protocol Effectiveness, %	Intention-To-Screen Effectiveness, %
Usual care	100.0	27.5	27.5
Clinic In-reach	51.2 (86/168)	88.4	52.4
Mailed FIT outreach	98.2 (168/171)	76.8–78.5a	77.2
Combination	99.4 (166/167; both 96,  outreach only = 67,  in-reach only = 3)	78.9	78.4

Note. FIT = fecal immunochemical test.

Source. Castañeda et al.

^aNot reported in Castañeda et al., but range calculated as 129/168–132/168.

Among individuals who successfully received the one-on-one education in-reach, for example, 88% completed CRC screening within six months, the highest rate for any of the study’s tested conditions (compared to 28% for usual care, 77% for mailed FIT outreach, and 79% for the combination of in-reach and outreach). Yet, because only 51% of the individuals who were assigned to the in-reach program actually received the program, the CRC screening completion, based on intention-to-screen analysis, dropped to 52%. By contrast, nearly all selected individuals were reached by usual care (100%), were mailed FIT outreach (98%), or received the combination of clinic in-reach and mailed FIT outreach (99%; Table 1). In reaching 98% of participants, the findings from Castañeda et al. show that the mailed FIT outreach’s reach was nearly double that of clinic in-reach; ultimately this difference in reach drives the reported difference in effectiveness.

How do the findings of Castañeda et al. compare with those of other studies? Studies that have mailed FITs to individuals overdue for screening have generally reported high reach rates and low proportions of individuals with invalid addresses.^4,5 Similar to the findings of Castañeda et al. on the reach for the in-reach strategy, Potter et al. reported reach rates for a flu–FIT clinic in an integrated health system, where FIT kits were distributed by clinic staff to overdue individuals attending a flu clinic. Their findings showed that 53.9% of individuals who were eligible to receive a FIT actually received one.⁶ Potter et al. note that implementation barriers and clinic processes likely accounted for the low distribution.

Castañeda et al. provide little insight into the reasons fewer patients were reached in the in-reach group. We know from previous research that some individuals cancel, reschedule, or do not show up for clinic visits and that cancelations and no-shows are particularly common in federally qualified health centers, where the study of Castañeda et al. was set. Federally qualified health center no-show rates have been reported to be as high as 20%.⁷ Other individuals may face pressing health needs and decline a 10-minute preventive health education session. It is also possible that the patient navigators delivering the program faced practical limitations to delivering education in a busy clinic, such as space constraints or cooccurring appointments.

What is unique about the study of Castañeda et al. is the practical decision to limit study participants to those who had a scheduled primary care visit in the upcoming two months. This decision allowed a direct comparison of distinct strategies while facilitating an individual randomized design. In this context, mailed FIT outreach may be particularly effective, as the clinic visit serves as an additional reminder to complete screening and provides a natural and timely way for patients to get answers to questions about the test (irrespective of whether one-on-one education was also delivered). Moreover, some individuals prefer to personally drop off their completed FIT to a clinic to ensure its receipt, and the clinic visit may provide a convenient way to accomplish this. However, systematically mailing FIT kits to individuals with upcoming clinic visits may present some practical challenges, especially for clinic systems with limited capacity to generate patient registries. One reason for this is that patient scheduling systems are usually distinct from other types of electronic health record data that are often used for establishing eligibility. These challenges limit the use of scheduling systems data for patient selection in population outreach programs.

The findings of Castañeda et al. are important for health systems seeking to select an intervention that can be successfully implemented in their setting. When delivered to Latino adults with an upcoming clinic visit, clinic in-reach and mailed FIT outreach are both effective at raising rates of CRC screening. There is no additive effect when combining these interventions, but mailed FIT outreach reached more individuals. As the research of Castañeda et al. demonstrates, effective strategies that successfully reach a broad population are needed to accelerate CRC prevention and save lives from the second most lethal form of cancer in the United States.