A Decision Aid for Patients With Age-related Cataract

Study Overview
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Brief Summary
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To determine whether a decision aid increases informed decision about cataract surgery for patients with age-related cataract.

Detailed Description
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The need for cataract surgery is on the rise globally due to the aging population and high demands for greater visual functioning. Patients with age-related cataract face their initial decision about when to undergo cataract surgery. Although the majority of patients want to participate in a shared decision-making process, no decision aid has been available to improve the quality of decision. The purpose of this study is to determine whether a decision aid increases informed decision about cataract surgery for patients with age-related cataract.

Official Title
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Patient-centered and Economic Effectiveness of a Decision Aid for Patients With Age-related Cataract: a Randomized Controlled Trial

Conditions
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Age-related Cataract

Intervention / Treatment
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* Other: A patient decision aid
* Other: A usual education booklet


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Individuals aged 50-80 years who have been resident in the selected study district for more than six months; A definite diagnosis of age-related cataract; Having not received cataract surgery; Willing to participate in the study and provide informed content. Exclusion criteria Bilateral blindness (presenting distance visual acuity worse than 3/60); Having ocular, hearing or mental disorder precluding reading or telephone interview; Ocular disorders other than cataract leading to permanent vision loss that could not be corrected through cataract surgery; Having cataract surgery contraindication.

Ages Eligible for Study
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Minimum Age: 50 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Health Services Research
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: A patient decision aid<br>A patient decision aid that includes not only the standard general information, but also the quantitative risk information on the possible outcomes of cataract surgery as well as value clarification exercise. | Other: A patient decision aid<br>* Potential participants receive a printed decision aid booklet with information about cataract surgery choice, and outcome data will be gathered using standardized questions in a structured interview after 2 weeks and 1 year.<br>|
| Active Comparator: A usual education booklet<br>A traditional booklet with standard general information developed by the National Eye Institute (NEI) to help patients understand cataract. | Other: A usual education booklet<br>* Potential participants receive a usual booklet about cataract and cataract surgery, and outcome data will be gathered using standardized questions in a structured interview after 2 weeks and 1 year.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Informed choice about cataract surgery (the proportion of participants who make an informed choice，which is defined as a good knowledge score and an intention that is consistent with their attitude score) | Informed choice is an aggregated measure of multiple measurements, including knowledge (a 12-item questionnaire that assesses conceptual (items 1-10) and numerical (items 11-12) knowledge), attitudes (6 items, with 5 responses for each), and intentions (single item with 5 responses) Analysis: Informed Choice= Good Knowledge (score ≥50% in basic knowledge, ≥40% in knowledge associated with each treatment option, and at least 1 point in each numerical knowledge question) AND Positive Attitude (score ≥24) AND Positive Intention (definitely will or likely to), OR Good Knowledge AND Negative Attitude (score <23) AND Negative Intention (unsure, not likely to, or definitely will not) | 2 weeks post intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Perceived importance of surgical benefit/harms | Purpose-developed items will be used to ask participants about their personal perceptions of the importance of specific outcomes in their decision-making about cataract surgery. | 2 weeks post intervention | 
| Perceived personal chances of surgical benefit/harms | Participants will be asked about their perceived personal likelihood of experiencing specific outcomes if they have cataract surgeries, compared with an average patient who had undergone cataract surgery. | 2 weeks post intervention | 
| Decisional conflict | Decisional conflict will be assessed using a 16-item Decisional Conflict Scale. | 2 weeks post intervention | 
| Decisional confidence | Decisional confidence will be assessed using a 11-item Decision Self Efficacy Scale. | 2 weeks post intervention | 
| Time perspective | This will be assessed using a 4-item short form of the Consideration of Future Consequences Scale, with five response categories ranging from strongly agree to strongly disagree. | 2 weeks post intervention | 
| Anticipated regret | Two items from a validated scale will measure anticipated regret about having cataract surgery (action regret) and about not having cataract (inaction regret). | 2 weeks post intervention | 
| Cataract worry and anxiety | A validated single item will measure participants' level of worry about progression of cataract, using four verbal response categories ranging from not worried at all to very worried. Anxiety will be measured with a six-item short form. | 2 weeks post intervention | 
| Booklet utilization and acceptability | Acceptability and utilization of materials will be assessed based on the following items: the proportion of participants who could read the booklet all the way through; the proportion of participants who agree that the information is new; the proportion of participants who agree that the length is just about right; the proportion of participants who think the information is balanced; the proportion of participants who agree that the booklet is clear and easy to understand; the proportion of participants who find the materials helpful; the proportion of participants who feel it worth recommending to others. | 2 weeks post intervention | 
| Undergoing cataract surgery | Self-reported undergoing cataract surgery will be assessed via telephone survey at 1 year. | 1 year post intervention | 
| Decision regret | The Decision Regret Scale will measure participants' level of regret regarding their initial decision whether to have cataract surgery or not. | 1 year post intervention | 
| Visual functioning | This will be assessed using the Catquest 9SF questionnaire. | Baseline, 1 year post intervention | 
| Fall questionnaire | This will be assessed using a single item question Did you have any fall in the past 12 months whereby you landed on the ground or floor? | 1 year post intervention | 
| Heath-related quality of life: Chinese version of the EQ-5D-5L telephone interview script | This will be assessed using the simplified Chinese version of the EQ-5D-5L telephone interview script from the EuroQol research foundation. | Baseline, 1 year post intervention | 
| Costs | This will be assessed using the Treatment Inventory of Costs in Patients with psychiatric disorders (TIC-P) questionnaire. | Baseline, 1 year post intervention |