<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT02244060</url>
  </required_header>
  <id_info>
    <org_study_id>vignette2014</org_study_id>
    <nct_id>NCT02244060</nct_id>
  </id_info>
  <brief_title>Eye Examinations as a Gold Standard to Evaluating Survey Instruments</brief_title>
  <official_title>Eye Examinations as a Gold Standard to Evaluating Survey Instruments</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>Harvard School of Public Health (HSPH)</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
    <collaborator>
      <agency>Jingning County in Zhejiang Province in China</agency>
      <agency_class>Other</agency_class>
    </collaborator>
  </sponsors>
  <source>Harvard School of Public Health (HSPH)</source>
  <oversight_info>
    <has_dmc>Yes</has_dmc>
  </oversight_info>
  <brief_summary>
    <textblock>
      Objective measures of health are relatively expensive; meanwhile, self-reports are critiqued&#xD;
      to be subjective and not comparable. A middle ground approach is to apply the frontier work&#xD;
      of vignette methods. The aim of the survey experiment is to explore the validity of survey&#xD;
      instruments to identify students who need glasses, using objectively measured visual acuity&#xD;
      as a gold standard. It is hypothesized that direct comparison against vignette (DCV) is&#xD;
      significantly different from indirect comparison against vignette (ICV); meanwhile,&#xD;
      self-assessment of vision (SAV) is significantly different from primed self-assessment of&#xD;
      vision (PSAV). It is also hypothesized that DCV is a more valid survey instrument than ICV to&#xD;
      classify students who need glasses, using objective visual acuity as a gold standard. Lastly,&#xD;
      it is hypothesized that priming effect from vignettes improves the validity of&#xD;
      self-assessment. It is planned to enroll 3,755 subjects in the survey experiment.&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      The schools will be visited to announce this project on survey experiment and measuring&#xD;
      visual acuity, for which all participants will receive free eye examinations. After receiving&#xD;
      consent/assent, two data collection strategies will be applied in this survey - DCV and ICV,&#xD;
      to identify individual perceptions of vision. In the arm of ICV, the self-assessment of&#xD;
      vision (SAV) is listed before the vignette questions; however, in the arm of DCV, the&#xD;
      self-assessed vision (PSAV) is listed after the vignette questions to estimate priming&#xD;
      effect. With randomization prior to administration of survey, 50% of the students will be&#xD;
      enrolled in &quot;direct comparison against vignettes&quot; (DCV) and another 50% for &quot;implied&#xD;
      comparison against vignettes&quot; (ICV). Each participant will self-administer the survey. The&#xD;
      objective measure of vision will be set up in a vacant classroom with assistance from members&#xD;
      of the Health Center Jingning County. DCV, ICV, SAV, and PSAV are estimated from randomized&#xD;
      survey questionnaires. Objectively measured vision is from simplified Snellen chart.&#xD;
&#xD;
      Measures - All subjects will be asked to respond to the questions about vision acuity without&#xD;
      glasses or contact lenses for themselves and these hypothetical scenarios. Information&#xD;
      collected through the survey includes self-assessed vision, vignettes, clusters (school,&#xD;
      grade, and class), whether the subjects wear glasses or contact lenses, and two demographic&#xD;
      variables (age and sex).&#xD;
&#xD;
      Self-assessed vision - Data of self-assessed vision is collected by asking students to think&#xD;
      about their own vision without glasses or contact lenses. Specifically, each student was&#xD;
      asked to respond to this question: &quot;at the present time, would you say your distance eyesight&#xD;
      is excellent, good, fair, poor, or very poor?&quot; Vignettes - The DCV questionnaire asks&#xD;
      subjects to jointly evaluate their own vision and vignette situations; meanwhile, the ICV&#xD;
      questionnaire asks subjects to conduct single evaluation of vignette questions. Even though&#xD;
      subjects in ICV questionnaires were not asked to compare their visual acuity with the&#xD;
      hypothetical person Zhang, the experimenter could conduct the comparison through data&#xD;
      analysis. Accordingly this approach is named the &quot;indirect comparison against vignettes&quot;&#xD;
      (ICV).&#xD;
&#xD;
      For example, in the DCV questionnaire, the subjects will be asked to respond to the following&#xD;
      question:&#xD;
&#xD;
      Sitting in the last row in the classroom, [Xiao Zhang] does recognize teacher's faces clearly&#xD;
      but cannot identify small hand writing on the blackboard clearly. Would you say your distance&#xD;
      eyesight is:&#xD;
&#xD;
        1. Better than Zhang's&#xD;
&#xD;
        2. The same as Zhang's&#xD;
&#xD;
        3. Worse than Zhang's Comparatively, in the ICV questionnaire, the subjects will be asked&#xD;
           to respond to the following question instead.&#xD;
&#xD;
      Sitting in the last row in the classroom, [Xiao Zhang] does recognize teacher's faces clearly&#xD;
      but cannot identify small hand writing on the blackboard clearly. Would you say [Zhang]'s&#xD;
      distance eyesight is:&#xD;
&#xD;
        1. Excellent,&#xD;
&#xD;
        2. Good,&#xD;
&#xD;
        3. Fair,&#xD;
&#xD;
        4. Poor, or&#xD;
&#xD;
        5. Very poor.&#xD;
&#xD;
      Two vignettes are designed in this study. More specifically, two hypothetical persons with&#xD;
      common Chinese names, Xiao Wang and Xiao Zhang will be introduced in the survey, who would be&#xD;
      mentioned as V1 and V2 in the following discussion.&#xD;
&#xD;
      V1: In the dining hall, [Xiao Wang] has no difficulty to see students on the same table&#xD;
      clearly but he cannot not see students on next tables clearly.&#xD;
&#xD;
      V2: Sitting in the last row in the classroom, [Xiao Zhang] does recognize teacher's faces&#xD;
      clearly but cannot identify small hand writing on the blackboard clearly.&#xD;
&#xD;
      The two vignettes is designed in the ascending level of visual acuity and the vignettes is&#xD;
      arranged in the questionnaires in this way: V1 and V2.&#xD;
&#xD;
      The question in DCV is, &quot;Would you say your distance eyesight is better than Wang's, the same&#xD;
      as Wang's, or worse than Wang's?&quot; and the question in ICV was, &quot;Would you say Wang's distance&#xD;
      eyesight is excellent, good, fair, poor, or very poor?&quot; respectively.&#xD;
&#xD;
      Objective visual acuity - The simplified Snellen chart only consists of letter &quot;E&quot; with&#xD;
      different directions, which was approved by the National Bureau of Standards in China to be a&#xD;
      national standard in testing visual acuity (GB115331989). It was approved by the Ministry of&#xD;
      Health to be used nationwide in China on March 27th, 1989. The simplified Snellen chart is&#xD;
      used to estimate visual acuity with the respondent standing at 5 meters. The measurement&#xD;
      ranges from 4.0 to 5.3, an arithmetic sequence with 0.1 progression. The larger the number&#xD;
      is, the better the respondent's vision is.&#xD;
&#xD;
      Capability to respond to this eye chart is most likely to be independent from educational&#xD;
      level. Furthermore, simplified Snellen chart also rules out of the difficulties of Snellen&#xD;
      letters and common misidentifications(Mathew, Shah et al. 2011). Therefore, it is less likely&#xD;
      than a standard Snellen chart to underestimate true vision due to low literacy rate. In the&#xD;
      line with vision 4.0, only one letter &quot;E&quot; is presented, and in the line with vision 4.1,&#xD;
      there are two &quot;E&quot;s. Except those two lines, the probability to overestimate true vision by&#xD;
      0.1 due to chance alone is smaller than 6.25% (i.e., 1/64), since a correct response to at&#xD;
      least three &quot;E&quot;s in each line is required in this survey experiment. More specifically, the&#xD;
      probability to guess the direction of one letter &quot;E&quot; correctly by chance is 1/4 and the&#xD;
      probability to guess the directions of three &quot;E&quot;s correctly by chance is only 1/64. Using eye&#xD;
      examination as a gold standard, the empirical research addressed the validity of vignette&#xD;
      methods.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Completed</overall_status>
  <start_date>September 2014</start_date>
  <completion_date type="Actual">October 2014</completion_date>
  <primary_completion_date type="Actual">October 2014</primary_completion_date>
  <phase>N/A</phase>
  <study_type>Interventional</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <allocation>Randomized</allocation>
    <intervention_model>Parallel Assignment</intervention_model>
    <masking>Single (Participant)</masking>
  </study_design_info>
  <primary_outcome>
    <measure>Self-assessed vision</measure>
    <time_frame>One and half months</time_frame>
  </primary_outcome>
  <primary_outcome>
    <measure>Direct comparison against vignette (DCV)</measure>
    <time_frame>One and half months</time_frame>
  </primary_outcome>
  <primary_outcome>
    <measure>Indirect comparison against vignette (ICV)</measure>
    <time_frame>One and half months</time_frame>
  </primary_outcome>
  <primary_outcome>
    <measure>Primed self-assessed vision</measure>
    <time_frame>One and half months</time_frame>
  </primary_outcome>
  <secondary_outcome>
    <measure>Objectively measured vision</measure>
    <time_frame>One and half months</time_frame>
  </secondary_outcome>
  <number_of_arms>2</number_of_arms>
  <enrollment type="Actual">4320</enrollment>
  <condition>Self Report</condition>
  <condition>Questionnaire Design</condition>
  <arm_group>
    <arm_group_label>Direct comparison</arm_group_label>
    <arm_group_type>Experimental</arm_group_type>
    <description>The Direct comparison against vignette (DCV) questionnaire asks subjects to estimate their own vision against vignette situations.Priming effect from vignette is designed in the arm of DCV.</description>
  </arm_group>
  <arm_group>
    <arm_group_label>Indirect comparison</arm_group_label>
    <arm_group_type>No Intervention</arm_group_type>
    <description>The Indirect comparison against vignette (ICV) questionnaire asks self-assessed vision and single evaluation of vignettes.</description>
  </arm_group>
  <intervention>
    <intervention_type>Other</intervention_type>
    <intervention_name>Priming effect from vignette</intervention_name>
    <description>In the arm of DCV, the self-assessed vision (PSAV) is listed after the vignette questions; however, in the arm of ICV, the self-assessment of vision (SAV) is listed before the vignette questions. Priming effect from vignette will be estimated by comparing those two randomized variables (i.e., SAV and PSAV).</description>
    <arm_group_label>Direct comparison</arm_group_label>
    <other_name>primed self-assessed vision</other_name>
    <other_name>primed self-assessment of vision</other_name>
  </intervention>
  <eligibility>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
        • Middle school students (i.e., Grade 7 to Grade12) in Jingning County.&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
        • Primary school students (i.e., Grade 1 to Grade 6) in Jingning County.&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>N/A</minimum_age>
    <maximum_age>N/A</maximum_age>
    <healthy_volunteers>Accepts Healthy Volunteers</healthy_volunteers>
  </eligibility>
  <overall_official>
    <last_name>Linyu Su</last_name>
    <role>Study Director</role>
    <affiliation>Jingning Health Center</affiliation>
  </overall_official>
  <location>
    <facility>
      <name>Jingning County</name>
      <address>
        <city>Lishui</city>
        <state>Zhejiang</state>
        <zip>323500</zip>
        <country>China</country>
      </address>
    </facility>
  </location>
  <location_countries>
    <country>China</country>
  </location_countries>
  <verification_date>April 2015</verification_date>
  <study_first_submitted>September 14, 2014</study_first_submitted>
  <study_first_submitted_qc>September 16, 2014</study_first_submitted_qc>
  <study_first_posted type="Estimate">September 18, 2014</study_first_posted>
  <last_update_submitted>April 5, 2015</last_update_submitted>
  <last_update_submitted_qc>April 5, 2015</last_update_submitted_qc>
  <last_update_posted type="Estimate">April 7, 2015</last_update_posted>
  <responsible_party>
    <responsible_party_type>Principal Investigator</responsible_party_type>
    <investigator_affiliation>Harvard School of Public Health (HSPH)</investigator_affiliation>
    <investigator_full_name>Yanfang Su</investigator_full_name>
    <investigator_title>Doctoral Candidate</investigator_title>
  </responsible_party>
  <keyword>Vignette</keyword>
  <keyword>Priming effect</keyword>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT02244060
org study id: vignette2014
nct id: NCT02244060
lead sponsor: 
collaborator: 
has dmc: Yes
Objective measures of health are relatively expensive; meanwhile, self-reports are critiqued
      to be subjective and not comparable. A middle ground approach is to apply the frontier work
      of vignette methods. The aim of the survey experiment is to explore the validity of survey
      instruments to identify students who need glasses, using objectively measured visual acuity
      as a gold standard. It is hypothesized that direct comparison against vignette (DCV) is
      significantly different from indirect comparison against vignette (ICV); meanwhile,
      self-assessment of vision (SAV) is significantly different from primed self-assessment of
      vision (PSAV). It is also hypothesized that DCV is a more valid survey instrument than ICV to
      classify students who need glasses, using objective visual acuity as a gold standard. Lastly,
      it is hypothesized that priming effect from vignettes improves the validity of
      self-assessment. It is planned to enroll 3,755 subjects in the survey experiment.
The schools will be visited to announce this project on survey experiment and measuring
      visual acuity, for which all participants will receive free eye examinations. After receiving
      consent/assent, two data collection strategies will be applied in this survey - DCV and ICV,
      to identify individual perceptions of vision. In the arm of ICV, the self-assessment of
      vision (SAV) is listed before the vignette questions; however, in the arm of DCV, the
      self-assessed vision (PSAV) is listed after the vignette questions to estimate priming
      effect. With randomization prior to administration of survey, 50% of the students will be
      enrolled in "direct comparison against vignettes" (DCV) and another 50% for "implied
      comparison against vignettes" (ICV). Each participant will self-administer the survey. The
      objective measure of vision will be set up in a vacant classroom with assistance from members
      of the Health Center Jingning County. DCV, ICV, SAV, and PSAV are estimated from randomized
      survey questionnaires. Objectively measured vision is from simplified Snellen chart.

      Measures - All subjects will be asked to respond to the questions about vision acuity without
      glasses or contact lenses for themselves and these hypothetical scenarios. Information
      collected through the survey includes self-assessed vision, vignettes, clusters (school,
      grade, and class), whether the subjects wear glasses or contact lenses, and two demographic
      variables (age and sex).

      Self-assessed vision - Data of self-assessed vision is collected by asking students to think
      about their own vision without glasses or contact lenses. Specifically, each student was
      asked to respond to this question: "at the present time, would you say your distance eyesight
      is excellent, good, fair, poor, or very poor?" Vignettes - The DCV questionnaire asks
      subjects to jointly evaluate their own vision and vignette situations; meanwhile, the ICV
      questionnaire asks subjects to conduct single evaluation of vignette questions. Even though
      subjects in ICV questionnaires were not asked to compare their visual acuity with the
      hypothetical person Zhang, the experimenter could conduct the comparison through data
      analysis. Accordingly this approach is named the "indirect comparison against vignettes"
      (ICV).

      For example, in the DCV questionnaire, the subjects will be asked to respond to the following
      question:

      Sitting in the last row in the classroom, [Xiao Zhang] does recognize teacher's faces clearly
      but cannot identify small hand writing on the blackboard clearly. Would you say your distance
      eyesight is:

        1. Better than Zhang's

        2. The same as Zhang's

        3. Worse than Zhang's Comparatively, in the ICV questionnaire, the subjects will be asked
           to respond to the following question instead.

      Sitting in the last row in the classroom, [Xiao Zhang] does recognize teacher's faces clearly
      but cannot identify small hand writing on the blackboard clearly. Would you say [Zhang]'s
      distance eyesight is:

        1. Excellent,

        2. Good,

        3. Fair,

        4. Poor, or

        5. Very poor.

      Two vignettes are designed in this study. More specifically, two hypothetical persons with
      common Chinese names, Xiao Wang and Xiao Zhang will be introduced in the survey, who would be
      mentioned as V1 and V2 in the following discussion.

      V1: In the dining hall, [Xiao Wang] has no difficulty to see students on the same table
      clearly but he cannot not see students on next tables clearly.

      V2: Sitting in the last row in the classroom, [Xiao Zhang] does recognize teacher's faces
      clearly but cannot identify small hand writing on the blackboard clearly.

      The two vignettes is designed in the ascending level of visual acuity and the vignettes is
      arranged in the questionnaires in this way: V1 and V2.

      The question in DCV is, "Would you say your distance eyesight is better than Wang's, the same
      as Wang's, or worse than Wang's?" and the question in ICV was, "Would you say Wang's distance
      eyesight is excellent, good, fair, poor, or very poor?" respectively.

      Objective visual acuity - The simplified Snellen chart only consists of letter "E" with
      different directions, which was approved by the National Bureau of Standards in China to be a
      national standard in testing visual acuity (GB115331989). It was approved by the Ministry of
      Health to be used nationwide in China on March 27th, 1989. The simplified Snellen chart is
      used to estimate visual acuity with the respondent standing at 5 meters. The measurement
      ranges from 4.0 to 5.3, an arithmetic sequence with 0.1 progression. The larger the number
      is, the better the respondent's vision is.

      Capability to respond to this eye chart is most likely to be independent from educational
      level. Furthermore, simplified Snellen chart also rules out of the difficulties of Snellen
      letters and common misidentifications(Mathew, Shah et al. 2011). Therefore, it is less likely
      than a standard Snellen chart to underestimate true vision due to low literacy rate. In the
      line with vision 4.0, only one letter "E" is presented, and in the line with vision 4.1,
      there are two "E"s. Except those two lines, the probability to overestimate true vision by
      0.1 due to chance alone is smaller than 6.25% (i.e., 1/64), since a correct response to at
      least three "E"s in each line is required in this survey experiment. More specifically, the
      probability to guess the direction of one letter "E" correctly by chance is 1/4 and the
      probability to guess the directions of three "E"s correctly by chance is only 1/64. Using eye
      examination as a gold standard, the empirical research addressed the validity of vignette
      methods.
allocation: Randomized
intervention model: Parallel Assignment
masking: Single (Participant)
measure: Self-assessed vision
time frame: One and half months
measure: Direct comparison against vignette (DCV)
time frame: One and half months
measure: Indirect comparison against vignette (ICV)
time frame: One and half months
measure: Primed self-assessed vision
time frame: One and half months
measure: Objectively measured vision
time frame: One and half months
arm group label: Direct comparison
arm group type: Experimental
description: The Direct comparison against vignette (DCV) questionnaire asks subjects to estimate their own vision against vignette situations.Priming effect from vignette is designed in the arm of DCV.
arm group label: Indirect comparison
arm group type: No Intervention
description: The Indirect comparison against vignette (ICV) questionnaire asks self-assessed vision and single evaluation of vignettes.
intervention type: Other
intervention name: Priming effect from vignette
description: In the arm of DCV, the self-assessed vision (PSAV) is listed after the vignette questions; however, in the arm of ICV, the self-assessment of vision (SAV) is listed before the vignette questions. Priming effect from vignette will be estimated by comparing those two randomized variables (i.e., SAV and PSAV).
arm group label: Direct comparison
other name: primed self-assessed vision
other name: primed self-assessment of vision
criteria: 
gender: All
minimum age: N/A
maximum age: N/A
healthy volunteers: Accepts Healthy Volunteers
last name: Linyu Su
role: Study Director
affiliation: Jingning Health Center
facility: 
country: China
responsible party type: Principal Investigator
investigator affiliation: Harvard School of Public Health (HSPH)
investigator full name: Yanfang Su
investigator title: Doctoral Candidate