Default Option Nudging Intervention to Improve the Adherence Rates of Cancer Screening

Default Option Nudging Intervention to Improve the Adherence Rates of Cancer Screening in High-risk Population: Randomized Controlled Trial and Intervention Disclosure Analysis

The goal of this clinical trial is to learn if a behavioral "nudge" strategy, specifically a default option, can improve screening participation in populations at high risk for lung and stomach cancer. The main questions it aims to answer are:

1. Does presenting a screening appointment as a default option increase the likelihood that high-risk individuals will choose to be screened?
2. How do participants react, and what is their level of acceptance, when the nudge intervention is disclosed to them?
3. Does this transparency (disclosing the nudge) change their subsequent screening decisions? Researchers will compare a default option group to a standard control group to see if the nudge effectively increases screening adherence.

Participants will:

1. Read a short educational text about lung or stomach cancer and its screening.
2. Complete an online questionnaire.
3. Make a decision regarding a simulated cancer screening appointment.
4. Read a disclosure explaining the behavioral nudge strategy used during the study.
5. Re-evaluate their screening decision and answer questions regarding their attitude toward the nudge.

Inclusion Criteria:

• High-risk population of lung cancer or gastric cancer.
• Lung cancer high-risk definition (based on the 2024 Lung Cancer Screening and Early Diagnosis and Treatment Program organized by the National Health Commission of the PRC): Age ≥50 years and pack-years of smoking ≥20, including former smoking ≥20 pack-years, but smoking cessation less than 15 years (Note: Pack-years of smoking = number of packs smoked per day × number of years smoked).
• Gastric cancer high-risk definition (based on the 2024 Gastric Cancer Screening and Early Diagnosis and Treatment Program organized by the National Health Commission of the PRC): Age ≥45 years old and living in areas with a high incidence of gastric cancer (Liaoning, Fujian, Gansu, Shandong, Jiangsu).
• Ability to read and comprehend simplified Chinese.
• The informed consent statement was read and confirmed.

Exclusion Criteria:

• Reading impairment preventing independent questionnaire completion.
• Failure to pass attention checks and logical consistency tests embedded within the questionnaire.