Pilot Testing a Web-based Prototype of a Lung Cancer Screening Digital Health Tool

Self-reported receipt of LCS within 3 months of exposure to the digital health tool

Intention to undergo LCS in the next 3 months, measured during the post-test survey administered immediately after viewing the digital health tool. Patient will respond on a 4-point agreement scale (strongly agree/agree/disagree/strongly disagree).

Stage of decision making will be assessed using the validated single-item Stage of Decision Making Scale. The measure assesses participants' readiness to make a decision regarding lung cancer screening by asking them to select one of six statements describing their current stage of decision making, ranging from not yet thinking about the decision to having made a decision and being unlikely to change their mind. Responses are coded on a 6-point ordinal scale, with higher scores indicating greater readiness or progression toward making a decision.

Acceptability will be assessed using the 10-item validated Ottawa Acceptability of Decision Aid Measure. The Ottawa Acceptability Measure has 8 items evaluating each section of the digital health tool (4-point Likert scale ranging from Poor to Excellent), length of presentation (too short/too long/just right), amount of information (too much/too little/just right), balance (slanted towards LCS/not slanted towards LCS/balanced), usefulness of the website (yes/no), risk calculation understanding (easy/difficult), and enough information (yes/no). The measure also includes two open-ended questions regarding what participants liked about the website and suggested improvements.

Website usability will be assessed using the 10-item validated System Usability Scale (SUS). The SUS evaluates participants' overall perceptions of the usability of the digital health tool, including ease of use, complexity, consistency, confidence while using the system, and willingness to use the system frequently. Each item is rated on a 5-point Likert scale ranging from Strongly disagree to Strongly agree. After reverse scoring negatively worded items, responses are summed and converted to a 0-100 scale, with higher scores indicating better perceived usability.

Knowledge of lung cancer screening will be assessed using the 20-item Lung Cancer Screening Knowledge Measure (LCS-15). The LCS-15 evaluates participants' knowledge of lung cancer screening, including eligibility criteria, screening frequency, potential benefits and harms of low-dose computed tomography (LDCT), false-positive results, overdiagnosis, incidental findings, radiation exposure, follow-up testing, and the importance of smoking cessation. Each item is answered using correct, incorrect, or "I don't know" response options. Correct responses are scored as 1, while incorrect and "I don't know" responses are scored as 0. Item scores are summed and converted to a 0-100% score, with higher scores indicating greater knowledge of lung cancer screening.

Perceived risk of lung cancer will be assessed using the 3-item Perceived Risk subscale of the validated Lung Cancer Screening Health Belief Scales (LCSHBS). The subscale measures participants' perceived susceptibility to developing lung cancer by assessing their perceived risk, likelihood of developing lung cancer in the next few years, and overall likelihood of developing lung cancer. Items are rated on a 4-point Likert scale ranging from Strongly disagree to Strongly agree. Responses are summed to produce a total score ranging from 3 to 12, with higher scores indicating greater perceived risk of developing lung cancer.

Perceived benefits of lung cancer screening will be assessed using the 6-item Perceived Benefits subscale of the validated Lung Cancer Screening Health Belief Scales (LCSHBS). The subscale evaluates participants' beliefs about the benefits of undergoing lung cancer screening with low-dose computed tomography (LDCT), including beliefs that screening can detect lung cancer early, improve treatment outcomes, and reduce the risk of dying from lung cancer. Items are rated on a 4-point Likert scale ranging from Strongly disagree to Strongly agree. Responses are summed to produce a total score ranging from 6 to 24, with higher scores indicating stronger perceived benefits of lung cancer screening.

Perceived barriers to lung cancer screening will be assessed using the 17-item Perceived Barriers subscale of the validated Lung Cancer Screening Health Belief Scales (LCSHBS). The subscale assesses participants' perceived emotional, practical, and logistical barriers to completing lung cancer screening, including concerns about cost, fear, time, transportation, inconvenience, and access. Items are rated on a 4-point Likert scale ranging from Strongly disagree to Strongly agree. Responses are summed to produce a total score ranging from 17 to 68, with higher scores indicating greater perceived barriers to lung cancer screening.

Decisional conflict will be assessed using the 4-item validated SURE Test. The SURE Test evaluates whether participants feel certain about the best choice, understand the benefits and risks of available options, are clear about which benefits and risks matter most to them, and have sufficient support and advice to make a decision. Items are answered using Yes/No response options. Responses are summed to produce a total score ranging from 0 to 4, with higher scores indicating less decisional conflict and greater confidence in decision making.

Preparation for decision making will be assessed using the 10-item validated Preparation for Decision Making Scale (PrepDM). The PrepDM measures the extent to which the digital health tool prepares participants to communicate with their healthcare provider and make an informed decision about lung cancer screening. Items assess whether the tool helped participants recognize that a decision needs to be made, understand the benefits and harms of screening, clarify what matters most to them, organize their thoughts, identify questions for their healthcare provider, and prepare to discuss their preferences and make a decision. Each item is rated on a 5-point Likert scale ranging from Not at all to A great deal. Item scores are averaged and transformed to a 0-100 scale, with higher scores indicating greater perceived preparation for decision making.