Increasing Colorectal Cancer Screening in Alaska Native Men
Phase: NA
Conditions: Colorectal Cancer
Sponsor: Washington State University

TITLE: Colorectal Cancer Screening in Alaska Native Men 
NCT: 06436300 
VERSION: June 30, 2023 
 
TABLE OF CONTENTS 
A. Objective…………………………………………... 2 
B. Background……………………………………….. 2 
C. Study Protocol…………………………………….. 2 
D. Statistical Analysis………………………………... 4 
E. Plan for Dissemination…………………………… 5 
F. References………………………………………… 5 
 

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A. Objective 
Conduct a randomized controlled trial to test the effect of the adapted motivational messaging intervention on 
colorectal cancer (CRC) screening with Alaska Native and American Indian (ANAI) men.  
 
B. Background 
ANAI men in Alaska experience the most 
profound CRC disparities of any US racial 
or ethnic group. In 2019 the American 
Cancer Society reported a CRC incidence 
of 100 per 100,000 for ANAI men, nearly 
twice the next highest incidence (58 per 
100,000) for non-Hispanic Blacks, and 
more than twice that for non-Hispanic 
Whites (46 per 100,000).1 Similarly, CRC 
mortality in ANAI men was nearly twice the 
rate for non-Hispanic Blacks (47 vs. 26 per 
100,000) and almost triple that for non-
Hispanic Whites (17 per 100,000). 
Approximately half of CRC deaths could 
be prevented by screening, which detects 
lesions in pre-cancerous or early-stage 
disease, when 5-year survival rates are 
much higher.2,3 Current guidelines 
recommend CRC screening for average-
risk adults starting at 45-50 years old, but 
those in high-risk groups (such as ANs) 
should start at younger ages.4,5 
Nationwide, 58%-65% of non-Hispanic 
Whites meet CRC screening guidelines, 
compared to 45%-54% of ANAI people.6,7  
In 2013 our team designed a text 
messaging intervention to promote CRC screening among ANAI customer-owners at Southcentral Foundation 
(SCF). The intervention involved sending up to 3 culturally informed text messages at 1-month intervals. All 
messages exclusively promoted colonoscopy. In a randomized controlled trial (RCT) with 2,386 customer-
owners 40-75 years old, our intervention led to a 50% increase in CRC screening in ANAI women – but it had 
no effect in ANAI men.8  
In light of these findings, the current study will test a version of the text messaging intervention that has been 
further adapted for ANAI men.  
 
C. Study Protocol 
C.1. Study Design and Outcomes 
This is a parallel-arm randomized controlled trial with four study conditions: usual care control; or usual care 
plus text messaging only (“Messages), text messaging and promise of a $50 gift card for completing CRC 
screening (“Gift Card”), or text messaging and promise of being entered into a raffle (~$200 prize value) for 
completing screening (“Raffle”). 
The original primary outcome was any completed CRC screening documented in the electronic medical record 
(EMR) during follow-up. During the intervention adaptation process, in response to community partner 
feedback we added scheduling a pre-screening visit or screening procedure as an additional primary outcome. 
C.2 Randomized Trial. The RCT will be implemented over approximately six months. We will query the EMR 
to randomly select 1000 male ANAI customer-owners aged 40-75 years who are eligible for routine CRC 
screening. The cohort will be further randomized into one of the four study arms. Randomization will be 
Figure 1. Randomized Controlled Trial Study Design. (Note the 
figure reflects a three-month follow-up; we were able to revise the 
timeline to allow six months of follow-up.)

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matched and stratified by age (40-49, 50-75) and location (Anchorage, Matanuska-Susitna Valley) to ensure 
balance of these factors in the study arms. Figure 1 depicts the RCT study design. The age range of 
participants reflects SCF clinical practice guidelines, as well as the earlier mean age at CRC incidence among 
ANAI people compared with other races and ethnicities.  
Intervention details 
The intervention comprises a series of up to four electronic messages delivered by text to a mobile phone 
and/or by email. Messages are sent approximately 2 weeks apart (total duration = 6 weeks). After sending 
each message, we will query the EHR so that men who have completed screening do not continue receiving 
messages. Men who have scheduled but not completed screening will not be removed from the list, due to 
high rates of no-shows for colonoscopy appointments. For men in the three intervention arms who are still 
unscreened and therefore eligible to receive the fourth message, we will select a random subset to receive an 
unsolicited mailed packet containing the Fecal Immunochemical Test (FIT) kit with a pre-paid return envelope 
to the mailing address on file. The total sample size for this subgroup will depend on costs and logistical 
feasibility, but we anticipate sending approximately 125 kits per arm (approximate total 375). Anchorage-
empaneled CO FIT kits will be returned to the SCF CRC team mailbox in MSD administration. The CRC team 
will receive the completed FIT kits and send the samples down to the ANPCC lab for processing. Valley-
empaneled CO kits will be returned to VNPCC lab, which will be prepared and sent via courier to ANMC lab. 
The fourth message will be different for men who are and are not randomly selected to receive unsolicited 
mailed FIT kits. For men who are not selected, the message will encourage them to call and request a mailed 
kit. For men who are selected, the message will inform men that they will receive a kit for completing a FIT 
screening at home. To ensure equitable access to receiving incentives, all study participants in any of the four 
arms who complete CRC screening before the final data query will receive a gift card and will be included in 
the raffle.   
Messages will be personalized by including the recipient’s name in the message salutation. SCF phone 
numbers and videos will be hyperlinked for participant convenience. The messages will include an option to 
respond with “SCF” if the participant wishes to be contacted by SCF about screening options. If a participant 
responds “SCF”, they will receive an automated response message and their primary care team will be notified 
of their interest. If a participant responds “Stop”, they will not receive an automated response message and no 
further messages will be sent. 
All men who complete colorectal cancer screening will receive the gift card incentive and be entered in the 
raffle, even if they were not informed in advance that this was possible. After the RCT is completed, we will 
send a final message to all men who did not receive any messages about gift card or raffle incentives and who 
did not complete screening during the study period. This message will inform the men that they can receive a 
gift card and be entered into a raffle if they complete screening within the next four weeks, and it will include 
the same contact information for accessing screening as the first message in Table 1. 
Sample Size, Eligibility, Randomization, Recruitment/Informed Consent, and Compensation 
One thousand customer-owners will be randomized in the RCT, with 250 assigned to each of the four study 
arms (Figure 1). Inclusion criteria are 1) male; 2) ANAI; 3) active SCF customer-owners; 3) aged 40-75; 4) no 
history of CRC or abnormal screening; and 5) due for CRC screening. Individuals who meet inclusion criteria 
but are at increased/high risk of CRC relative to race-, age-, and gender-matched peers (e.g., due to family 
history of CRC) are not eligible to participate. 
The EMR will be queried to identify customer-owners eligible to participate in the study and to extract data for 
study outcomes. Only those individuals who are (1) members of the study team who and (2) members of the 
SCF Data Services department will have access to identifiable customer-owner information or be directly 
involved in the following study activities: determining the eligibility of customer-owners; de-identifying the data 
of eligible customer-owners; randomizing eligible customer-owners to control or intervention arms of the RCT; 
sending motivational messages to eligible customer-owners; and sharing fully de-identified participant data 
with other members of the study team for analysis.  
All study data will be obtained directly from the EMR and will therefore not involve active recruitment of any 
individual patient. Additionally, study data will not include any identifiable customer-owner information. We 

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have obtained a waiver of consent, which was granted warranted because 1) our study is designed to increase 
uptake of existing screening guidelines; 2) the intervention will not interfere with usual care; and 3) directly 
recruiting and consenting participants into the RCT might lead to heightened awareness and uptake of CRC 
screening, which could increase the risk of Type 2 error (failure to detect a beneficial intervention effect) in the 
RCT. All messages sent to customer-owners will include instructions for opting out of further communications.  
There is no compensation provided for the RCT, because no customer-owner will be asked to contribute any 
time or effort to completing an intervention or engaging in data collection. 
Data Collection 
All study data will be obtained from the EMR. SCF Data Services staff will extract and de-identify data, and 
assign unique study IDs to individuals included in the dataset. De-identified data will be securely transmitted to 
Dr. Clemma Muller at Washington State University for analysis. The dataset will be stored on a HIPPA-
compliant secure server that is backed up daily to an off-side location. Files at Washington State University will 
be password protected and accessible only to Dr. Muller. A member of the study team who also works in the 
SCF Data Services will retain a second copy of the de-identified study dataset on a password-protected, 
secure network server at SCF. Table 1 lists the variables that will be extracted from the EMR.  
 
Table 1. Measures to be extracted from the electronic medical record for the RCT
Variable
Categories or Units
Intended use
Age
40-45; 46-49; 50-59; 60-75
Eligibility, cohort description, 
subgroup analyses
Gender
Men only
Eligibility
Race
ANAI only
Eligibility
Screening history
Only people without previous 
abnormal CRC screening results
Eligibility
CRC history
Only people with no previous 
CRC diagnosis
Eligibility
Location 
Urban/suburban; rural
Cohort description, subgroup 
analyses
Previous CRC screening history
Never screened at SCF; 
previously screened by 
colonoscopy; previously screened 
by other method
Cohort description, subgroup 
analyses 
Duration of overdue screening 
eligibility
Years (to 1 decimal place)
Cohort description, subgroup 
analyses
Total SCF clinic visits in the past 
year
Count
Cohort description, subgroup 
analyses
CRC screening completed
Type of test
Month in which test occurs
Primary outcome
CRC screening or pre-screening 
scheduled
Yes, No
Primary outcome
CRC = colorectal cancer; SCF = Southcentral Foundation
 
D. Statistical analysis 
All data analysis will be conducted with Stata version 16 or later (StataCorp, College Station, TX) or R 
statistical software packages. We will report descriptive statistics for all study variables as counts and 
frequencies for categorical factors, and as means, standard deviations, and ranges for continuous factors. 
Descriptive results will be presented separately for men in the intervention and control conditions. Our 
inferential analysis will use an intent-to-treat approach, using data for all participants in the group to which they 
were assigned, regardless of events that occur after randomization. We will use logistic regression with 
marginal standardization to estimate the effect of the intervention on CRC screening. Results will be presented 
as risk ratios and risk differences with 95% confidence intervals. Marginal standardization estimates are 

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interpreted as the difference in CRC screening if everyone received the intervention compared to screening if 
no one received the intervention, in a population with the same distribution of regression model covariates as 
observed in the study sample. If deemed appropriate, the regression model specification may be adjusted 
(e.g., binomial regression) prior to conducting the statistical analysis. Our primary analysis will estimate the 
effect of assignment to the intervention group without adjusting for any covariates, as appropriate for a large 
RCT. Sensitivity analyses will adjust for any other variables that appear unbalanced between groups at 
baseline, and secondary analyses will evaluate potential modification of intervention effectiveness by variables 
such as age, location, and history of CRC screening.  
 
E. Plan for Dissemination 
Results from this study will be submitted for publication in the peer-reviewed literature and/or for presentation 
at scientific conferences. We will also seek out opportunities to share results with SCF and Tribal leadership, 
customer-owners, and other stakeholders. Documents containing study results (e.g., manuscripts, 
presentations) will not be made available to the public unless they have first been reviewed and approved by 
SCF Tribal Review. 
 
Published results will include a summary of participant responses to interview and survey questions, as well as 
summary data from the RCT. These results will not include any information that would identify individual 
participants. These results may include direct quotations from interviews. 
 
F. References 
1. Siegel RL, Miller KD, Jemal A. Cancer statistics, 2019. CA Cancer J Clin 2019;69:7-34. 
2. Zauber AG, Winawer SJ, O'Brien MJ, et al. Colonoscopic polypectomy and long-term prevention of colorectal-cancer 
deaths. N Engl J Med 2012;366:687-96. 
3. Zhang J, Cheng Z, Ma Y, et al. Effectiveness of Screening Modalities in Colorectal Cancer: A Network Meta-Analysis. 
Clin Colorectal Cancer 2017;16:252-63. 
4. Smith RA, Andrews KS, Brooks D, et al. Cancer screening in the United States, 2017: A review of current American 
Cancer Society guidelines and current issues in cancer screening. CA Cancer J Clin 2017;67:100-21. 
5. Rahman R, Schmaltz C, Jackson CS, Simoes EJ, Jackson-Thompson J, Ibdah JA. Increased risk for colorectal cancer 
under age 50 in racial and ethnic minorities living in the United States. Cancer Med 2015;4:1863-70. 
6. Colorectal Cancer Facts and Figures, 2014-2016. Atlanta, GA: American Cancer Society; 2014. 
7. Siegel RL, Miller KD, Fedewa SA, et al. Colorectal cancer statistics, 2017. CA Cancer J Clin 2017;67:177-93. 
8. Muller CJ, Robinson RF, Smith JJ, et al. Text message reminders increased colorectal cancer screening in a 
randomized trial with Alaska Native and American Indian people. Cancer 2017;123:1382-9.