Risk and Risk Perception of Knee Osteoarthritis in the US

Study Overview
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Brief Summary
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The investigators have created an interactive knee osteoarthritis (OA) risk calculator that estimates a user's risk of developing symptomatic knee OA as well as the user's risk for undergoing a total knee replacement (TKR) within their lifetime. To test the impact of the calculator, the investigators recruited OA-free subjects from Amazon's Mechanical Turk. Participants were randomized to either access general information about OA or use the risk calculator in addition to accessing general OA information. The investigators hypothesized that participants randomized to the risk calculator arm would have more accurate perception of their knee OA risk and would have increased willingness to change risky behavior compared to the general OA information group.

Official Title
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Raising Awareness of Knee Osteoarthritis (OA) and Willingness to Undertake Behavioral Changes to Reduce Risk of Knee OA: Online Recruitment

Conditions
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Knee Osteoarthritis

Intervention / Treatment
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* Behavioral: Internet-Based Osteoarthritis Risk Calculator
* Behavioral: Generic osteoarthritis information


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participants must be between the ages of 25 and 45 Participants must live in the United States Participants must not be diagnosed with osteoarthritis Exclusion Criteria: All participants who did not meet the inclusion criteria

Ages Eligible for Study
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Minimum Age: 25 Years
Maximum Age: 45 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: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Sham Comparator: Generic Osteoarthritis Risk Information<br>Participants in this arm received generic osteoarthritis information that was not personalized. | Behavioral: Generic osteoarthritis information<br>* Subjects viewed generic (i.e. not personalized) information about osteoarthritis risk factors<br>|
| Experimental: Personalized Osteoarthritis Risk<br>Participants in this arm obtained their personalized osteoarthritis risk from the internet-based Osteoarthritis Risk Calculator. | Behavioral: Internet-Based Osteoarthritis Risk Calculator<br>* The investigators have developed a personalized risk calculator for knee osteoarthritis. This risk calculator uses the Osteoarthritis Policy Model to estimate an individual's risk of developing knee osteoarthritis within their lifetime based on demographic information and risk factors. It shows this information to the user with interactive graphs and compares their risk to the risk of an average American of the same age.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in estimated lifetime knee OA risk | The difference between average lifetime knee osteoarthritis risk estimated by participants at baseline and average lifetime knee osteoarthritis risk estimated by participants after the intervention. | 1 day | 
| Change in estimated 10-year knee OA risk | The difference between average 10-year knee osteoarthritis risk estimated by participants at baseline and average 10-year knee osteoarthritis risk estimated by participants after the intervention. | 1 day | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Reaching an Action Stage on Diet Contemplation Ladder | The percentage of subjects who originally ranked themselves below an action stage (8 or higher) on a contemplation ladder for changing diet related behaviors and who moved to an action stage after the intervention. | 1 day | 
| Reaching an Action Stage on Exercise Contemplation Ladder | The percentage of subjects who originally ranked themselves below an action stage (8 or higher) on a contemplation ladder for changing exercise related behaviors and who moved to an action stage after the intervention. | 1 day | 
| Reaching an Action Stage on Weight Control Contemplation Ladder | The percentage of subjects who originally ranked themselves below an action stage (8 or higher) on a contemplation ladder for changing weight control behaviors and who moved to an action stage after the intervention. | 1 day |