In the past two decades, internet and mobile phone usage has increased due to affordability. The COVID-19 pandemic has further necessitated online and phone-based healthcare, paving the way for less labor-intensive, cost-effective mHealth interventions. These include short message service (SMS) text messages, telephone calls, email, social media, and mobile apps, which have significantly boosted BC screening uptake by 1.2%-50.9%. Among them, manual calls and SMS are prevalent methods. Manual calls facilitate interactions with subjects, aiding informed decision-making and participation but require high manpower. Although SMS offers automatic communication and chatbot features, each message costs approximately HKD$0.2, posing long-term economic challenges, especially for population-based interventions. Conversely, chatbots based on mobile messengers, like WhatsApp are less expensive due to unlimited free text and multimedia messaging across different mHealth operating systems. WhatsApp is globally prevalent, including in HK and has been successfully implemented in various clinical settings. Given these promising results, the investigators believe that mobile messenger-initiated chatbots have an extended role in the BC screening uptake rate because of the ubiquity, acceptability, and effectiveness of mHealth interventions. However, studies evaluating combined theory-based mHealth interventions to enhance BC screening uptake are scarce.
