COVID-19NCT05642754
Glassy Trial for Effects of Wearing Glasses
A study testing Overall uncertainty language in people with COVID-19, run by Trustees of Dartmouth College at 1 site in Norway.
Trial summary
Randomized trial testing 6 forms of a communication summarizing the results of a recent study (about the effects of wearing glasses on reducing covid infection risk). The goal of the trial is to test the effect of different language options to describe uncertainty, and of including the margin of error around the main… Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- COVID-19
- What is being tested?
- Overall uncertainty language
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 960 participants
- Where
- 1 siteNorway
- Study dates
- 1 Dec 2022to 31 Mar 2023
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- >= 18 years old
- literate in English or Norwegian
- currently residing in Norway or the United States
Who cannot join
- individuals who regularly wear any kind of glasses (i.e., prescription or sunglasses) all or most of the time
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Communicating Uncertainty About the Effects of Wearing Glasses to Reduce the Chance of Getting COVID (Corona Virus Disease): Protocol for a Randomized Trial
Randomized trial testing 6 forms of a communication summarizing the results of a recent study (about the effects of wearing glasses on reducing covid infection risk).
The goal of the trial is to test the effect of different language options to describe uncertainty, and of including the margin of error around the main result.
Read the detailed description
The study is designed as a proof-of-concept exercise to develop and test a communication meant to summarize the results of a recent randomized trial examining the effects of wearing glasses on the chance of developing COVID-19.
The objectives of the randomized trial are:
- To compare the effects of three ways of communicating the overall uncertainty of the effects of wearing glasses to reduce the chance of getting COVID and
- To compare the effects of including the margin of error (confidence interval) compared to not including it.
Researchers will conduct an online, parallel group, individually randomized, pragmatic trial using a 3x2 factorial design, ie, 3 uncertainly language options (GRADE language, colloquial language or none 2 options for the statistical margin of error for the main results (margin of error language or none).
- Conditions
- COVID-19
- Being tested
- Overall uncertainty language
- Keywords
- Colloquial language, uncertainty, bias
- Medical subject headings
- COVID-19
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Overall uncertainty languageOther
Also called Margin of error around main result
Researchers are testing different forms of information about overall study uncertainty and margin of error around main result
| Study group | Role | What they receive |
|---|---|---|
| GRADE + margin of error | Active comparator | Overall uncertainty using GRADE* language AND margin of error around main result
* Based on the Cochrane Effective Practice and Organisation of Care Group's guidance for communicating the certainty of evidence based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to assessing the certainty of evidence Receives: Other: Overall uncertainty language |
| Colloquial language AND margin of error | Active comparator | Colloquial language developed to describe overall study uncertainty AND margin of error around main result Receives: Other: Overall uncertainty language |
| No overall uncertainty language AND margin of error | Active comparator | No overall uncertainty language AND margin of error around main result Receives: Other: Overall uncertainty language |
| GRADE -No margin of error | Active comparator | Overall uncertainty using GRADE* language and NO margin of error around main result
* Based on the Cochrane Effective Practice and Organisation of Care Group's guidance for communicating the certainty of evidence based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to assessing the certainty of evidence Receives: Other: Overall uncertainty language |
| Colloquial - No margin of error | Active comparator | Colloquial language developed to describe overall study uncertainty and NO margin of error around main result Receives: Other: Overall uncertainty language |
| No overall uncertainty language AND no margin of error | Placebo comparator | No overall uncertainty language and NO margin of error around main result Receives: Other: Overall uncertainty language |
What is being measured
The primary outcome is the main question the study is designed to answer.
understanding of overall uncertainty of benefit (of wearing glasses to reduce the chance of covid infection)
How sure about the effect (4 point scale from very unsure to very sure)
Measured: within 1 day
understanding of overall uncertainty of harm (of wearing glasses to reduce the chance of covid infection)
How sure about the effect (4 point scale from very unsure to very sure)
Measured: within 1 day
sufficiency of what is known about the effects of wearing glasses to reduce the chance of covid infection
How sure about the effect (4 point Likert scale)
Measured: within 1 day
Understanding the margin of error around the benefit of wearing glasses to reduce covid
this is a co-primary outcome which will be used only to compare the 3 versions that include the margin of error to the 3 versions that do not
Measured: within 1 day
Secondary outcomes (13)
perceived effect of wearing glasses to reduce chance of covid infection
What is the effect on a 5 point scale (lowers a lot, lowers a little, no effect, increase a little, increases a lot
Measured: within 1 day
how likely is it that wearing glasses reduces the chance of covid infection
4 point scale (very likely, likely, unlikely, very unlikely)
Measured: within 1 day
intended behavior (if there were a surge in covid in your area, how likely would you be to wear glasses to reduce the chance of covid infection
4 point scale (very likely, likely, unlikely, very unlikely
Measured: within 1 day
intended behavior (if there were very few cases of covid in your area, how likely would you be to wear glasses to reduce the chance of covid infection
4 point scale (very likely, likely, unlikely, very unlikely
Measured: within 1 day
perceptions fo information provided (trustworthy summary?)
4 point Likert scale (strongly agree, agree, disagree, strongly disagree)
Measured: within 1 day
perceptions fo information provided (sufficient summary?)
4 point Likert scale (strongly agree, agree, disagree, strongly disagree)
Measured: within 1 day
perceptions fo information provided (clarity of info about benefit)
4 point scale (very clear, clear, unclear, very unclear)
Measured: within 1 day
perceptions fo information provided (clarity of info about harm)
4 point scale (very clear, clear, unclear, very unclear)
Measured: within 1 day
perceptions fo information provided (info helpful?)
4 point scale (very helpful, helpful, unhelpful, very unhelpful)
Measured: within 1 day
perceptions fo information provided (share info with others?)
4 point scale (definitely yes, probably yes, probably no, definitely no)
Measured: within 1 day
Decisional conflict (hard to make decision)
4 point LIkert scale (strongly agree, agree, disagree, strongly disagree)
Measured: within 1 day
Decisional conflict (made informed decision)
4 point LIkert scale (strongly agree, agree, disagree, strongly disagree)
Measured: within 1 day
Decisional conflict (satisfied with decision)
4 point LIkert scale (strongly agree, agree, disagree, strongly disagree)
Measured: within 1 day
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Dec 2022
- Study start1 Dec 2022
- Primary completion31 Jan 2023
- Study completion31 Mar 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for COVID-19Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Factorial
- Model description
- 3 options for describing bias/uncertainty about results 2 options for margin of error around main result (we will run the trial twice on 2 different online platforms)
- Masking
- Single blind
- Who is masked
- Investigator
- Enrolment
- 960 participants (actual)
Sponsor and investigators
- Lead sponsor
- Trustees of Dartmouth College
- Sponsor type
- University, hospital or other
- Collaborators
- Norwegian Institute of Public Health
- Responsible party
- Sponsor
- Investigators
- Steven Woloshin, MD, Principal investigator, Dartmouth Institute for Health Policy and Clincal PracticeAndy Oxman, MD, Principal investigator, Norwegian Institute of Public Health
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05642754
- Sponsor's protocol ID
- 557972
- Other IDs
- CPHS 32615
- Status last verified
- May 2024
- First submitted
- 30 Nov 2022
- Last updated
- 22 May 2024
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Holst C, Woloshin S, Oxman AD, Rose C, Rosenbaum S, Munthe-Kaas HM. Alternative Presentations of Overall and Statistical Uncertainty for Adults' Understanding of the Results of a Randomized Trial of a Public Health Intervention: Parallel Web-Based Randomized Trials. JMIR Public Health Surveill. 2025 Mar 18;11:e62828. doi: 10.2196/62828.
PubMed 40101228
Study at a glance
From the registry record, last updated by the sponsor on 22 May 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Communicating Uncertainty About the Effects of Wearing Glasses to Reduce the Chance of Getting COVID (Corona Virus Disease): Protocol for a Randomized Trial
- ClinicalTrials.gov ID
- NCT05642754
- Acronym / sponsor ID
- 557972
- Conditions
- COVID-19
- Keywords
- Colloquial language, uncertainty, bias
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 960 participants (actual)
- Lead sponsor
- Trustees of Dartmouth CollegeUniversity, hospital or other
- Collaborators
- Norwegian Institute of Public Health
- Study start
- 1 Dec 2022 (actual)
- Primary completion
- 31 Jan 2023 (actual)
- Study completion
- 31 Mar 2023 (actual)
- First posted
- 8 Dec 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Randomized trial testing 6 forms of a communication summarizing the results of a recent study (about the effects of wearing glasses on reducing covid infection risk).
The goal of the trial is to test the effect of different language options to describe uncertainty, and of including the margin of error around the main result.
Detailed description
The study is designed as a proof-of-concept exercise to develop and test a communication meant to summarize the results of a recent randomized trial examining the effects of wearing glasses on the chance of developing COVID-19.
The objectives of the randomized trial are:
- To compare the effects of three ways of communicating the overall uncertainty of the effects of wearing glasses to reduce the chance of getting COVID and
- To compare the effects of including the margin of error (confidence interval) compared to not including it.
Researchers will conduct an online, parallel group, individually randomized, pragmatic trial using a 3x2 factorial design, ie, 3 uncertainly language options (GRADE language, colloquial language or none 2 options for the statistical margin of error for the main results (margin of error language or none).
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Factorial
- Masking
- Single blind (investigator)
- Number of arms
- 6
- Model description
- 3 options for describing bias/uncertainty about results 2 options for margin of error around main result (we will run the trial twice on 2 different online platforms)
| Arm | Type | Receives |
|---|---|---|
| GRADE + margin of error | Active comparator | Other: Overall uncertainty languageOverall uncertainty using GRADE* language AND margin of error around main result * Based on the Cochrane Effective Practice and Organisation of Care Group's guidance for communicating the certainty of evidence based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to assessing the certainty of evidence |
| Colloquial language AND margin of error | Active comparator | Other: Overall uncertainty languageColloquial language developed to describe overall study uncertainty AND margin of error around main result |
| No overall uncertainty language AND margin of error | Active comparator | Other: Overall uncertainty languageNo overall uncertainty language AND margin of error around main result |
| GRADE -No margin of error | Active comparator | Other: Overall uncertainty languageOverall uncertainty using GRADE* language and NO margin of error around main result * Based on the Cochrane Effective Practice and Organisation of Care Group's guidance for communicating the certainty of evidence based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to assessing the certainty of evidence |
| Colloquial - No margin of error | Active comparator | Other: Overall uncertainty languageColloquial language developed to describe overall study uncertainty and NO margin of error around main result |
| No overall uncertainty language AND no margin of error | Placebo comparator | Other: Overall uncertainty languageNo overall uncertainty language and NO margin of error around main result |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- >= 18 years old
- literate in English or Norwegian
- currently residing in Norway or the United States
Key exclusion criteria (1 listed)
- individuals who regularly wear any kind of glasses (i.e., prescription or sunglasses) all or most of the time
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Overall uncertainty languageAlso: Margin of error around main resultResearchers are testing different forms of information about overall study uncertainty and margin of error around main result | Other | Colloquial - No margin of error, Colloquial language AND margin of error, GRADE + margin of error, GRADE -No margin of error, No overall uncertainty language AND margin of error, No overall uncertainty language AND no margin of error |
Primary outcome
understanding of overall uncertainty of benefit (of wearing glasses to reduce the chance of covid infection)
Time frame: within 1 day
How sure about the effect (4 point scale from very unsure to very sure)
understanding of overall uncertainty of harm (of wearing glasses to reduce the chance of covid infection)
Time frame: within 1 day
How sure about the effect (4 point scale from very unsure to very sure)
sufficiency of what is known about the effects of wearing glasses to reduce the chance of covid infection
Time frame: within 1 day
How sure about the effect (4 point Likert scale)
Understanding the margin of error around the benefit of wearing glasses to reduce covid
Time frame: within 1 day
this is a co-primary outcome which will be used only to compare the 3 versions that include the margin of error to the 3 versions that do not
13 secondary outcomes
perceived effect of wearing glasses to reduce chance of covid infection
Time frame: within 1 day
how likely is it that wearing glasses reduces the chance of covid infection
Time frame: within 1 day
intended behavior (if there were a surge in covid in your area, how likely would you be to wear glasses to reduce the chance of covid infection
Time frame: within 1 day
intended behavior (if there were very few cases of covid in your area, how likely would you be to wear glasses to reduce the chance of covid infection
Time frame: within 1 day
perceptions fo information provided (trustworthy summary?)
Time frame: within 1 day
perceptions fo information provided (sufficient summary?)
Time frame: within 1 day
perceptions fo information provided (clarity of info about benefit)
Time frame: within 1 day
perceptions fo information provided (clarity of info about harm)
Time frame: within 1 day
perceptions fo information provided (info helpful?)
Time frame: within 1 day
perceptions fo information provided (share info with others?)
Time frame: within 1 day
Decisional conflict (hard to make decision)
Time frame: within 1 day
Decisional conflict (made informed decision)
Time frame: within 1 day
Decisional conflict (satisfied with decision)
Time frame: within 1 day
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 May 2024.
- Derived from this study: PubMed 40101228Holst C, Woloshin S, Oxman AD, Rose C, Rosenbaum S, Munthe-Kaas HM. Alternative Presentations of Overall and Statistical Uncertainty for Adults' Understanding of the Results of a Randomized Trial of a Public Health Intervention: Parallel Web-Based Randomized Trials. JMIR Public Health Surveill. 2025 Mar 18;11:e62828. doi: 10.2196/62828.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Steven Woloshin, MD principal investigator
Dartmouth Institute for Health Policy and Clincal Practice
Andy Oxman, MD principal investigator
Norwegian Institute of Public Health
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Overall uncertainty language in people with COVID-19, run by Trustees of Dartmouth College at 1 site in Norway.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 22 May 2024. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Norway. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
understanding of overall uncertainty of benefit (of wearing glasses to reduce the chance of covid infection) (time frame: within 1 day). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05642754, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 May 2024; AzTrials last refreshed its copy on 7 Nov 2026.