Consumer Motivation for Disease Prevention 2 (Clear Labels)

Study Overview
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Brief Summary
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The purpose of this study is to examine (1) how the causal structure of a disease influences people's disease prevention decisions; and (2) how the causal structure of a disease interacts with people's regret anticipation in determining their disease prevention decisions.

Detailed Description
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People sometimes have to deliberate on whether or not to remove a risk factor that may potentially cause a disease in the future. When a modifiable risk factor (say, X) is the only factor that causes a disease, the decision to remove it may simply depend on the probabilistic relationship between X and an outcome, as well as the cost of removing X. However, little is known when other factors that are out of the decision-maker's control are also present. The main question being asked here is how does the presence of such non-modifiable factors change people's decision to remove X. Specifically, the investigators consider two cases: a disease caused by a single modifiable risk factor (say X) and a disease caused by two risk factors -- a modifiable factor (X) and a non-modifiable factor (Y). In both cases, the removal of X can result in a meaningful reduction in overall disease risk. It is hypothesized that even when the magnitude of overall risk reduction brought by the removal of X is the same in the two cases, people would have a lower motivation to remove X in the latter case. The investigators also examine how the presence of a non-modifiable risk factor interacts with the respondents' regret anticipation to influence their decision to remove X. In the context of the current research, regret anticipation could take one of the following forms: (a) feel regretful if one decides not to remove X and later develops the disease (b) feel regretful if one decides to remove X but still develops the disease. The investigators expect (a) to moderate the effect of non-modifiable risk factor on motivation to remove X.

Official Title
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Consumer Motivation for Disease Prevention 2 (Clear Labels)

Conditions
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Risk Reduction

Intervention / Treatment
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* Other: non-modifiable factor
* Other: induction of anticipated regret


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: students currently studying at the Chinese University of Hong Kong Exclusion Criteria: None

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Factorial Assignment
Interventional Model Description: Factorial Assignment The study has a 2 (Factor: one modifiable cause vs. one modifiable + one non-modifiable causes) ✕ 2 (Anticipated regret induction: yes vs. no) between-subject design. Participants will be randomly assigned to one of the 4 between-subject conditions. There is also a within-subject variable. Each subject will respond to 10 rounds of decision task with 5 different levels of overall disease risk reduction brought by the removal of X. The 5 levels of risk reduction are: (i) Removal of X reduces disease risk from 60% to 50% ; (ii) 60% to 40%; (iii) 60% to 30%; (iv) 60% to 20%; (v) 60% to 10%.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Non-modifiable factor ABSENT; NO anticipated regret induced<br>The experiment comprises 10 rounds of decision tasks. Participant begins with 130 points (each worth HK$0.5) in each round. After the 10 rounds, the computer randomly selects 1 round and the points from this round is paid in cash. There is a chance for the participant to develop a disease. Without prevention, the chance of getting the disease is 60%. A cause, X, is identified for the disease. X is a modifiable cause, which means that it can be changed by taking some actions. The participant has to decide whether or not to remove X. Removal of X reduces disease chance; the reduced chance varies between 10% and 50% across the 10 rounds and the exact level is communicated at the beginning of each round. The removal of X costs 30 points. Whether s/he ends up developing the disease or not is determined by a computerized lottery based on these chances. If s/he develops the disease, s/he will lose 100 points. | |
| Experimental: Non-modifiable factor ABSENT; anticipated regret induced<br>Same description as in the uncontrollable factor absent, no anticipated regret induced arm, except that the participants are induced to think to what extent they will feel regretful: a) if s/he decides not to remove X but ends up developing the disease and b) if s/he decides to remove X but still gets the disease. | Other: induction of anticipated regret<br>* higher level of elaboration on potential regret<br>|
| Experimental: Non-modifiable factor PRESENT; NO anticipated regret induced<br>The experiment comprises 10 rounds of decision tasks. Participant begins with 130 points (each worth HK$0.5) in each round. After the 10 rounds, the computer randomly selects 1 round and the points from this round is paid in cash. There is a chance for the participant to develop a disease. Without prevention, the chance of getting the disease is 60%. Two causes, X and Y, are identified for the disease. X is a modifiable cause, which means that it can be changed by taking some actions. The participant has to decide whether or not to remove X. Removal of X reduces disease chance; the reduced chance varies between 10% and 50% across the 10 rounds and the exact level is communicated at the beginning of each round. The removal of X costs 30 points. Whether s/he ends up developing the disease or not is determined by a computerized lottery based on these chances. If s/he develops the disease, s/he will lose 100 points. | Other: non-modifiable factor<br>* the presence of an uncontrollable / unremovable risk factor for a disease<br>|
| Experimental: Non-modifiable factor PRESENT; anticipated regret induced<br>Same as the uncontrollable factor present, no anticipated regret induced arm, except that the participants are induced to think to what extent they will feel regretful: a) if s/he decides not to remove X but ends up developing the disease and b) if s/he decides to remove X but still gets the disease. | Other: non-modifiable factor<br>* the presence of an uncontrollable / unremovable risk factor for a disease<br>Other: induction of anticipated regret<br>* higher level of elaboration on potential regret<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Decision to remove X | The decision to remove X (yes vs. no) | Day 1: When responding to the questionnaire |