Alaska Native men have the highest rates of colorectal cancer incidence and mortality in the US. Screening can prevent disease and improve survival. A previous study tested text messages to increase colorectal cancer screening in Alaska Native patients of the Southcentral Foundation healthcare system in Anchorage, Alaska. The intervention improved screening by 50% in women, but it had no effect in men. The current study aimed to culturally tailor the intervention for Alaska Native Men, and to test it with a randomized controlled trial among patients at the Southcentral Foundation.

Alaska Native men have higher colorectal cancer (CRC) incidence and mortality than any other US racial or ethnic group. Screening can prevent CRC and improve treatment outcomes by detecting disease in early stages, but Alaska Native men also have low CRC screening uptake. Colonoscopy is the most accurate CRC screening method and results in the most years of life saved. It only requires rescreening every 10 years, but it is a clinic- based procedure and needs extensive preparation. Other screening options include home-based tests that detect blood in the stool and require rescreening every year. More recently, a home-based method has been developed that tests stool for DNA indicative of CRC and requires rescreening every 3 years. Current guidelines recommend CRC screening for average risk adults starting between ages 45-50, but people at higher risk should start at younger ages. Many interventions have been developed to promote CRC screening. Among these, interventions that use text messaging or other electronic health messages to reach people outside of the clinical setting have shown promise for improving CRC screening. In a previous study, the research team developed an intervention that sends up to 3 text messages to Alaska Native people patients of the Southcentral Foundation (SCF) healthcare system in Anchorage, Alaska. The intervention was tested in a randomized controlled trial with 2,386 Alaska Native SCF patients ages 40-75. The intervention increased CRC screening by 50% in women, but it had no effect in men. The current study used a theory-based approach to culturally tailor the previous text message intervention for Alaska Native men. Investigators conducted a randomized trial to test the effectiveness of the tailored intervention with 998 Alaska Native men ages 40-75 who were active patients at SCF. Eligible men were identified from the electronic medical record and randomized in equal proportions to the control condition or to one of three intervention arms (messages only, messages plus gift card incentive, messages plus raffle incentive). The primary outcomes were completed CRC screening documented in the electronic medical record within 6 months of sending the first text message, and any scheduled visit for pre-screening or screening documented in the medical record during follow-up. The study obtained a waiver of consent, and no individuals were directly recruited or enrolled in the study. Follow-up was entirely ascertained through the electronic medical record, and cohort attrition was not applicable.

Inclusion Criteria:

• Alaska Native or American Indian racial identity
• Male gender identity
• Active patient of the Southcentral Foundation in Anchorage, Alaska
• Empanelled to primary care provider in the Anchorage or local Valley area
• Eligible for routine preventive colorectal cancer screening

Exclusion Criteria:

• None

Eligibility determined in the electronic medical record, which reflects gender identity.

Six months, from date of randomization to end of follow-up

This study was limited to male patients at a single Tribal health care system in the Anchorage Metropolitan Area. Results may not generalize to other Alaska Native or American Indian people in other locations or settings.

Colorectal cancer screening performed outside of the health care system would not be included in outcome data, but the vast majority of patients receive most or all their care from the Southcentral Foundation and we anticipate minimial misclassification of screening.