Effectiveness of Using Mobile Health Technology in Colorectal Cancer Screening Uptake

In Hong Kong, Colorectal cancer (CRC) ranked second in both cancer incidence and mortality, accounting for 16.7% of all new cancer cases and 14.6% of all cancer-related deaths in 2019. There was a staggering 2.5-fold increase in the number of newly diagnosed CRC cases from 1584 to 2019.

The fecal immunochemical test (FIT) helps reduce the incidence and mortality of CRC and is widely used for population-based CRC screening. The government-subsidized CRC screening program was launched in Hong Kong as a pilot in 2015 and fully implemented in 2020. The program was subsidized for asymptomatic Hong Kong residents, aged 50-75 years, to receive FIT screening every two years. A subsidized follow-up colonoscopy was offered for a positive FIT result. For a negative FIT result, the participant was advised to repeat the screening two years later.

Despite the subsidy and promotion, the uptake rate of the population-based colorectal cancer screening was low. Only 275,000 (\~10%) underwent FIT screening under this program as of 31st December 2021. Efforts have been made to increase the rate. Outreach is the active dissemination of screening outside of the primary care setting, and it also includes mailing, texting, and calling to encourage scheduling of screening procedures.

All eligible subjects will be randomized and allocated to receive either intervention (chatbot) or standard of care (text reminder) in a 1:1 allocation ratio. A fully automated chatbot will be developed and maintained in collaboration with IT experts on the WhatsApp Messenger platform for its wide popularity in local older adults and user-friendly interfaces for extensions. Depending on the randomization group, it delivers either a standard text reminder of CRC screening or health education in text and video formats with a series of questions on personalized risk assessment of CRC and information of primary care physicians under a government-subsidized CRC screening program according to the subject's preferred district. The same professional team will maintain the health status of the chatbot during the intervention period. A monthly review of chatbot performance will be conducted. A feedback loop is also incorporated into the chatbot, and users are invited to leave comments. Accordingly, improvements will be made, and the questions raised by the subjects will be collected and used to construct a data bank for the future development of Artificial intelligence (AI)-enabled chatbots.

It was technically infeasible to conduct fecal test outreach by mailing the test kits in Hong Kong because the government-subsidized colorectal cancer screening program required consultation with a primary care physician to assess the subjects' health condition, and their eligibility before distributing the fecal test kits. Similar to colonoscopy screening outreach, an alternative method is to provide contact information with primary care physicians located in the subject's preferred district via mobile messenger-based chatbots to arrange a consultation for FIT screening. Chatbots have already proven to be useful in increasing the intention to vaccinate against COVID-19.

Moreover, CRC screening uptake is highly associated with Health Belife Model (HBM) constructs and high risk perception of developing CRC is associated with higher screening uptake rate. HBM-based education and Trans-Theoretical Model (TTM)-based personalized risk assessment of CRC may increase the screening uptake rate by improving their knowledge of CRC screening (in terms of susceptivity, perceived benefits, and cues to actions) and informing subjects that they are at a relatively higher risk of developing CRC.

The CRC screening uptake rate in Hong Kong was 10%, and there is no established evidence to increase the uptake rate of FIT screening for CRC by outreach using mobile health technology or psychological theory-based interventions. A theory-based mobile messenger-initiated chatbot is a potential solution to this problem.

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Telephone follow-up

All subjects will be interviewed by phone three and six months after recruitment and asked if they have participated in the government-subsidized CRC screening program and CRC screening completion rate. The date of participation, completion of CRC screening, and FIT results will also be assessed. The reasons for not participating in the CRC screening program will be documented. We will also ask the subjects who have completed CRC screening if our chatbot or text reminder motivated them to uptake or there is exposure to any possible confounders, e.g., community initiative, related symptom onset, healthcare worker advice and family member or friend initiative, etc. A cash coupon of $50 Hong Kong Dollar will be mailed to the subject upon completion of telephone follow-up.

Focus group discussions

12 focus group discussions (6-8 participants per group) will be conducted after the telephone follow-up. The purpose of the focus group discussions is to identify the process factors to understand how the study intervention influence screening uptake behaviors and explore the complexity of FIT screening and reveal, based on the participants' accounts, the barriers, and facilitators for them to uptake FIT screening. Six groups from each RCT arm will be convened. For each discussion session, an experienced moderator from our research team will introduce our study aims, lead the discussion in a semi-structured format based on the discussion protocol, and ask clarifications when necessary. Another assistant will take notes and address contingent issues. Each focus group will be audiotaped and last for 1.5-2.5 hours. All participants will sign a written consent form before the focus group session and will be given some incentives at the end of the session to compensate for their time.

Eligibility Criteria:
Inclusion Criteria:

* 50-75 years old
* asymptomatic and eligible to enroll in a government-subsidized colorectal cancer screening program
* subjects themselves or their family members living in the same household with access to WhatsApp Messenger
* able to read Chinese
* willingness to be followed up by telephone

Exclusion Criteria:

* subject without access to WhatsApp Messenger
* unable to provide informed consent