Validation, test-retest reliability and norm scores for the Dutch Catquest-9SF
(2017) In Acta Ophthalmologica 95(3). p.312-319- Abstract
Purpose: The Catquest-9SF questionnaire is a unidimensional, reliable, valid and short patient-reported outcome measure for quantifying benefits in visual functioning from cataract surgery. Our aim was to develop a formal Dutch translation, calculate norm scores, assess its validity and test-retest reliability and provide an easy way for use in clinical practice. Methods: Translation of the questionnaire was performed according to guidelines of the International Society for Pharmacoeconomics and Outcomes Research. Catquest-9SF was obtained in 657 patients pre- and postcataract surgery. We applied Rasch and classical analyses to determine the questionnaire performance with characteristics such as unidimensionality, reliability,... (More)
Purpose: The Catquest-9SF questionnaire is a unidimensional, reliable, valid and short patient-reported outcome measure for quantifying benefits in visual functioning from cataract surgery. Our aim was to develop a formal Dutch translation, calculate norm scores, assess its validity and test-retest reliability and provide an easy way for use in clinical practice. Methods: Translation of the questionnaire was performed according to guidelines of the International Society for Pharmacoeconomics and Outcomes Research. Catquest-9SF was obtained in 657 patients pre- and postcataract surgery. We applied Rasch and classical analyses to determine the questionnaire performance with characteristics such as unidimensionality, reliability, separation and differential item functioning. Test-retest reliability was assessed in another group of 145 patients. A cut-off value to discriminate between people with and without cataract, norm scores and a reliable change index (RCI) were calculated using data from a sample of 916 'healthy' persons from the normal population. Results: The Dutch Catquest-9SF was unidimensional, and both person and item reliability were high; 0.87 and 0.99, respectively. Cronbach's alpha was 0.94, test-retest reliability was 0.85 and the intraclass correlation coefficient was 0.93. Catquest-9SF showed to be responsive to the effect of cataract surgery (effect size = 1.27; p < 0.001). The cut-off value was -1.90, and RCI was 2.27. A quick-access table with norm scores and percentiles was established to facilitate clinical interpretation. Conclusion: This investigation provides validity and reliability of the Dutch Catquest-9SF as well as norm scores and a new tool to facilitate the clinical interpretation of patient scores. This makes Catquest-9SF suitable for routine use in clinical practice.
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- author
- Visser, Martijn S. ; Dieleman, Myrthe ; Klijn, Stijn ; Timman, Reinier ; Lundström, Mats LU ; Busschbach, Jan J V and Reus, Nicolaas J.
- organization
- publishing date
- 2017
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Norm scores, Patient related outcome measures, Quality of life, Questionnaire, Test-retest reliability
- in
- Acta Ophthalmologica
- volume
- 95
- issue
- 3
- pages
- 312 - 319
- publisher
- Wiley-Blackwell
- external identifiers
-
- pmid:27775237
- wos:000399359400037
- scopus:84996940139
- ISSN
- 1755-375X
- DOI
- 10.1111/aos.13287
- language
- English
- LU publication?
- yes
- id
- 433c1c2d-2fe0-4838-ab94-d5b10ae11dec
- date added to LUP
- 2016-12-30 13:56:58
- date last changed
- 2024-04-19 16:22:56
@article{433c1c2d-2fe0-4838-ab94-d5b10ae11dec,
abstract = {{<p>Purpose: The Catquest-9SF questionnaire is a unidimensional, reliable, valid and short patient-reported outcome measure for quantifying benefits in visual functioning from cataract surgery. Our aim was to develop a formal Dutch translation, calculate norm scores, assess its validity and test-retest reliability and provide an easy way for use in clinical practice. Methods: Translation of the questionnaire was performed according to guidelines of the International Society for Pharmacoeconomics and Outcomes Research. Catquest-9SF was obtained in 657 patients pre- and postcataract surgery. We applied Rasch and classical analyses to determine the questionnaire performance with characteristics such as unidimensionality, reliability, separation and differential item functioning. Test-retest reliability was assessed in another group of 145 patients. A cut-off value to discriminate between people with and without cataract, norm scores and a reliable change index (RCI) were calculated using data from a sample of 916 'healthy' persons from the normal population. Results: The Dutch Catquest-9SF was unidimensional, and both person and item reliability were high; 0.87 and 0.99, respectively. Cronbach's alpha was 0.94, test-retest reliability was 0.85 and the intraclass correlation coefficient was 0.93. Catquest-9SF showed to be responsive to the effect of cataract surgery (effect size = 1.27; p < 0.001). The cut-off value was -1.90, and RCI was 2.27. A quick-access table with norm scores and percentiles was established to facilitate clinical interpretation. Conclusion: This investigation provides validity and reliability of the Dutch Catquest-9SF as well as norm scores and a new tool to facilitate the clinical interpretation of patient scores. This makes Catquest-9SF suitable for routine use in clinical practice.</p>}},
author = {{Visser, Martijn S. and Dieleman, Myrthe and Klijn, Stijn and Timman, Reinier and Lundström, Mats and Busschbach, Jan J V and Reus, Nicolaas J.}},
issn = {{1755-375X}},
keywords = {{Norm scores; Patient related outcome measures; Quality of life; Questionnaire; Test-retest reliability}},
language = {{eng}},
number = {{3}},
pages = {{312--319}},
publisher = {{Wiley-Blackwell}},
series = {{Acta Ophthalmologica}},
title = {{Validation, test-retest reliability and norm scores for the Dutch Catquest-9SF}},
url = {{http://dx.doi.org/10.1111/aos.13287}},
doi = {{10.1111/aos.13287}},
volume = {{95}},
year = {{2017}},
}