The Impact of Choice on Colorectal Cancer Screening

Colorectal cancer (CRC) is the second leading cause of cancer-related death for both men and women in the United States. One in 17 Americans will suffer from CRC during their lifetime and early detection of cancers and polyps by screening is shown to reduce CRC mortality. In 2021, the USPSTF updated its CRC screening guidelines to start screening average-risk individuals at the age of 45 years due in part to a rising incidence of CRC and premalignant polyps in younger patients.

Conventional screening options include both invasive (or direct-visualization) and non-invasive (or stool-based) options. Invasive screening tests include flexible sigmoidoscopy, CT colonography, and colonoscopy. Non-invasive screening tests include the fecal immunochemical test (FIT), the high sensitivity guaiac fecal occult blood test, and stool DNA testing. All of these screening tests are recommended by the USPSTF for CRC screening.

Nationally (and at UCLA Health), the two most common CRC screening modalities are the colonoscopy and the FIT. UCLA Health has previously implemented a FIT mailer outreach program wherein FIT kits are mailed to average-risk patients overdue for CRC screening twice annually to promote screening uptake. The program has been extremely effective in increasing CRC screening adherence rates, with an increase in the health system's screening rate over the past several years.

The investigators current study aims to determine the most effective patient outreach approach to maximize CRC screening utilization in average-risk individuals ages 45-49 years. In addition, the investigators aim to understand the impact of screening modality choice on uptake of CRC screening, patients' preference for screening modality, and sociodemographic differences in screening utilization among individuals ages 45-49 years.

There are approximately 18,000 patients eligible for inclusion. The investigators will randomly assign approximately 17,000 average-risk patients aged 45-49 to one of four arms. 1,000 of the patients will be reserved for an internal pilot project. In all arms, all patients will receive a text message encouraging them to access their patient communication portal via Epic electronic health record (EHR) (referred to as "MyChart"). In all arms, once a patient visits MyChart, a message on MyChart will state that they are due for CRC screening and the importance of CRC screening. In the control (standard care) arm, patients will treated as part of our "FIT-kit mailer program." These patients will receive a mailed FIT kit, and the message on MyChart will encourage them to complete the FIT kit. In the "FIT Kit Choice" arm, patients will be presented with the choice to complete screening with a FIT kit or opt out of screening. In the "Colonoscopy Choice" arm, patients will be presented with the choice to complete screening with a colonoscopy or opt out of screening. In the "Dual Choice" arm, patients will be presented with the choice to complete screening with a FIT kit, complete screening with a colonoscopy, or opt out of screening. After patients make the choice in MyChart, the patient will be asked why they made that choice.

We will resend the message on MyChart (as a reminder) two weeks after they receive the initial MyChart message. The reminder message content will be very similar to the content of initial MyChart message, and differ by arm.

The investigators have competing predictions based on the literature about whether giving people the option of choosing between two screening modalities (vs. neither) is better than giving people the option of deciding whether to take one modality (vs. not). On the one hand, offering people two modalities should increase flexibility and thus enhance participation; on the other hand, choosing between two modalities could tax mental resources and create choice avoidance, thus decreasing participation. Specifically:

In addition, the investigators have competing predictions based on the literature about whether active choice is better than assigning people a screening modality. On one side, active choice can make patients feel more empowered, thus enhancing participation in screening. On the other side, active choice takes more of patients' cognitive and time resources than following the assigned option, thus decreasing participation in screening.

Analysis Plan:

• Patient-level linear regression models with robust standard errors
• The primary model term will be indicator variables for arms that patients are assigned to.
• Covariates will include age, sex, race/ethnicity, social vulnerability index (ZIP code level), and baseline HM focus measure completion rate
• Treatment effects will be summarized using rate differences and 95% confidence intervals
• Exploratory analyses will investigate heterogeneous treatment effects by splitting the sample into demographic subgroups and by testing for demographic x choice arm interactions
• Sensitivity analyses will be performed without covariates, and using logistic regression models in place of linear regression models
• Missing covariate values will be handled by including 'unknown' indicators, along with mean imputation for quantitative covariates
• To analyze the effect of offering a choice between modalities (vs. single choice), we will compare the single choice arms (arms 1 and 2) with the dual choice arm (arm 3).
• To analyze the effect of active choice, we will compare the control arm (arm 0) with (1) active FIT choice arm (arm 1) and (2) the dual choice arm (arm 3).
• To assess both the effect of offering the dual choice (vs. single choice) and the effect of active choice, we will analyze two samples: (1) patients who open their initial MyChart message within 1 week of the date sent and (2) intention-to-treat regardless of whether patients open the MyChart message. In addition, when assessing the effect of offering the dual choice (vs. single choice), we will also examine patients who open either the initial or the reminder MyChart message within 1 week.