Study | Objectives | Outcomes | Predictors | Hypothesis | Outcome measure | Methods of analysis |
---|---|---|---|---|---|---|
Pilot stage | ||||||
Determine feasibility | (A) Recruitment rate | 2 Participants/week | Participants per week | |||
(B) Time to conduct the interview and finish all the measurements | 1 h would be optimal | Interview duration | ||||
(C) Patients’ attrition | Less than 5% | Patients’ attrition rate | ||||
Study 1: interview study | Primary | (A) Delay time | Age, gender, ethnicity, educational level, social economics status and medical history | Trade-off exercise | Normally distributed: mean delay time +SD; mean delay time and CI If data are skewed: mode, median and IQR | |
Secondary | (A) Patients’ anticipated regret scores | 100 mm visual analogue scale | t test | |||
Study 2: RCT | Primary | (A) Patients’ satisfaction on the HSs | Higher satisfaction on the short version | 7-point Likert-type scale | t test | |
Secondary | (A) Understandability | Both have rated as 5/7 | 7-point Likert-type scale | t test | ||
(B) Information quantity | Short will be rated at 4; long will be rated at 5 | 7-point Likert-type scale | t test | |||
(C) Patients’ preference on the length of format | Prefer the short version | 7-point Likert-type scale | t test or Mann-Whitney U test | |||
Sensitivity analyses | Patients’ satisfaction on the HSs | Higher satisfaction on the short version | 7-point Likert-type scale | Mann-Whitney U test | ||
Comprehensibility | Both have 5/7 | 7-point Likert-type scale | Mann-Whitney U test | |||
Information quantity | Short will be 4; long will be 5 | 7-point Likert-type scale | Mann-Whitney U test | |||
Patients’ preference on the length of format | Prefer the short version | 7-point Likert-type scale | Mann-Whitney U test |
HS, health scenario; RCT, randomised controlled trial.