Visual Functioning Questionnaire: reevaluation of psychometric properties for a group of working-age adults

Maaike Langelaan, Ruth M A van Nispen, Dirk L Knol, Annette C Moll, Michiel R de Boer, Bill Wouters, Ger H M B van Rens

Research output: Contribution to JournalArticleAcademicpeer-review

Abstract

PURPOSE: The Visual Functioning Questionnaire (VFQ-25) is one of the most widely used measures of vision-related quality of life. However, the questionnaire does not meet some psychometric quality criteria. The objectives of this study were first to obtain the factor structure of the VFQ-25, and second, to obtain interval scales by Rasch analysis.

METHODS: The questionnaire was administered to 129 visually impaired adults (mean age 42.1 years; range 21 to 67 years). First, the items of the VFQ-25 were subjected to an exploratory factor analysis with Promax rotation. Next, we performed a separate Rasch analysis on each factor. We examined step thresholds and goodness of fit statistics of the items. Finally, we examined differential item functioning.

RESULTS: Factor analysis indicated four factors: Near Activities, Distance Activities and Mobility, Mental Health and Dependency, and Pain and Discomfort. They accounted for 46.37% of the total variance. Most items showed some degree of disordering. After collapsing response categories, all items showed ordered thresholds. The Near Activities domain showed excellent fit, whereas the Distance Activities and Mobility domain, the Mental Health and Dependency domain, and the Pain and Discomfort domain had an unsatisfactory fit. There were two items showing uniform differential item functioning.

CONCLUSIONS: The four-factor structure of the VFQ-25 largely confirms the structure of the questionnaire. However, the results of this study suggest that modifications of the original VFQ-25 structure are necessary.

Original languageEnglish
Pages (from-to)775-84
Number of pages10
JournalOptometry and Vision Science
Volume84
Issue number8
DOIs
Publication statusPublished - Aug 2007

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Psychometrics
Age Groups
Statistical Factor Analysis
Mental Health
Pain
Quality of Life
Surveys and Questionnaires
Dependency (Psychology)

Keywords

  • Accommodation, Ocular
  • Adult
  • Aged
  • Asthenopia
  • Dependency (Psychology)
  • Factor Analysis, Statistical
  • Female
  • Humans
  • Male
  • Mental Health
  • Middle Aged
  • Models, Psychological
  • Models, Statistical
  • Movement
  • Pain
  • Psychometrics
  • Quality of Life
  • Surveys and Questionnaires
  • Vision, Low
  • Visual Acuity
  • Journal Article
  • Research Support, Non-U.S. Gov't

Cite this

Langelaan, Maaike ; van Nispen, Ruth M A ; Knol, Dirk L ; Moll, Annette C ; de Boer, Michiel R ; Wouters, Bill ; van Rens, Ger H M B. / Visual Functioning Questionnaire : reevaluation of psychometric properties for a group of working-age adults. In: Optometry and Vision Science. 2007 ; Vol. 84, No. 8. pp. 775-84.
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abstract = "PURPOSE: The Visual Functioning Questionnaire (VFQ-25) is one of the most widely used measures of vision-related quality of life. However, the questionnaire does not meet some psychometric quality criteria. The objectives of this study were first to obtain the factor structure of the VFQ-25, and second, to obtain interval scales by Rasch analysis.METHODS: The questionnaire was administered to 129 visually impaired adults (mean age 42.1 years; range 21 to 67 years). First, the items of the VFQ-25 were subjected to an exploratory factor analysis with Promax rotation. Next, we performed a separate Rasch analysis on each factor. We examined step thresholds and goodness of fit statistics of the items. Finally, we examined differential item functioning.RESULTS: Factor analysis indicated four factors: Near Activities, Distance Activities and Mobility, Mental Health and Dependency, and Pain and Discomfort. They accounted for 46.37{\%} of the total variance. Most items showed some degree of disordering. After collapsing response categories, all items showed ordered thresholds. The Near Activities domain showed excellent fit, whereas the Distance Activities and Mobility domain, the Mental Health and Dependency domain, and the Pain and Discomfort domain had an unsatisfactory fit. There were two items showing uniform differential item functioning.CONCLUSIONS: The four-factor structure of the VFQ-25 largely confirms the structure of the questionnaire. However, the results of this study suggest that modifications of the original VFQ-25 structure are necessary.",
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author = "Maaike Langelaan and {van Nispen}, {Ruth M A} and Knol, {Dirk L} and Moll, {Annette C} and {de Boer}, {Michiel R} and Bill Wouters and {van Rens}, {Ger H M B}",
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Visual Functioning Questionnaire : reevaluation of psychometric properties for a group of working-age adults. / Langelaan, Maaike; van Nispen, Ruth M A; Knol, Dirk L; Moll, Annette C; de Boer, Michiel R; Wouters, Bill; van Rens, Ger H M B.

In: Optometry and Vision Science, Vol. 84, No. 8, 08.2007, p. 775-84.

Research output: Contribution to JournalArticleAcademicpeer-review

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AU - Langelaan, Maaike

AU - van Nispen, Ruth M A

AU - Knol, Dirk L

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N2 - PURPOSE: The Visual Functioning Questionnaire (VFQ-25) is one of the most widely used measures of vision-related quality of life. However, the questionnaire does not meet some psychometric quality criteria. The objectives of this study were first to obtain the factor structure of the VFQ-25, and second, to obtain interval scales by Rasch analysis.METHODS: The questionnaire was administered to 129 visually impaired adults (mean age 42.1 years; range 21 to 67 years). First, the items of the VFQ-25 were subjected to an exploratory factor analysis with Promax rotation. Next, we performed a separate Rasch analysis on each factor. We examined step thresholds and goodness of fit statistics of the items. Finally, we examined differential item functioning.RESULTS: Factor analysis indicated four factors: Near Activities, Distance Activities and Mobility, Mental Health and Dependency, and Pain and Discomfort. They accounted for 46.37% of the total variance. Most items showed some degree of disordering. After collapsing response categories, all items showed ordered thresholds. The Near Activities domain showed excellent fit, whereas the Distance Activities and Mobility domain, the Mental Health and Dependency domain, and the Pain and Discomfort domain had an unsatisfactory fit. There were two items showing uniform differential item functioning.CONCLUSIONS: The four-factor structure of the VFQ-25 largely confirms the structure of the questionnaire. However, the results of this study suggest that modifications of the original VFQ-25 structure are necessary.

AB - PURPOSE: The Visual Functioning Questionnaire (VFQ-25) is one of the most widely used measures of vision-related quality of life. However, the questionnaire does not meet some psychometric quality criteria. The objectives of this study were first to obtain the factor structure of the VFQ-25, and second, to obtain interval scales by Rasch analysis.METHODS: The questionnaire was administered to 129 visually impaired adults (mean age 42.1 years; range 21 to 67 years). First, the items of the VFQ-25 were subjected to an exploratory factor analysis with Promax rotation. Next, we performed a separate Rasch analysis on each factor. We examined step thresholds and goodness of fit statistics of the items. Finally, we examined differential item functioning.RESULTS: Factor analysis indicated four factors: Near Activities, Distance Activities and Mobility, Mental Health and Dependency, and Pain and Discomfort. They accounted for 46.37% of the total variance. Most items showed some degree of disordering. After collapsing response categories, all items showed ordered thresholds. The Near Activities domain showed excellent fit, whereas the Distance Activities and Mobility domain, the Mental Health and Dependency domain, and the Pain and Discomfort domain had an unsatisfactory fit. There were two items showing uniform differential item functioning.CONCLUSIONS: The four-factor structure of the VFQ-25 largely confirms the structure of the questionnaire. However, the results of this study suggest that modifications of the original VFQ-25 structure are necessary.

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KW - Male

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KW - Pain

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KW - Quality of Life

KW - Surveys and Questionnaires

KW - Vision, Low

KW - Visual Acuity

KW - Journal Article

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