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Validation of Catquest-9SF-A Visual Disability Instrument to Evaluate Patient Function after Corneal Transplantation

Claesson, Margareta; Armitage, W. John; Byström, Berit; Montan, Per; Samolov, Branka; Stenvi, Ulf and Lundström, Mats LU (2017) In Cornea 36(9). p.1083-1088
Abstract

Purpose: Catquest-9SF is a 9-item visual disability questionnaire developed for evaluating patient-reported outcome measures after cataract surgery. The aim of this study was to use Rasch analysis to determine the responsiveness of Catquest-9SF for corneal transplant patients. Methods: Patients who underwent corneal transplantation primarily to improve vision were included. One group (n = 199) completed the Catquest-9SF questionnaire before corneal transplantation and a second independent group (n = 199) completed the questionnaire 2 years after surgery. All patients were recorded in the Swedish Cornea Registry, which provided clinical and demographic data for the study. Winsteps software v.3.91.0 (Winsteps.com, Beaverton, OR) was used... (More)

Purpose: Catquest-9SF is a 9-item visual disability questionnaire developed for evaluating patient-reported outcome measures after cataract surgery. The aim of this study was to use Rasch analysis to determine the responsiveness of Catquest-9SF for corneal transplant patients. Methods: Patients who underwent corneal transplantation primarily to improve vision were included. One group (n = 199) completed the Catquest-9SF questionnaire before corneal transplantation and a second independent group (n = 199) completed the questionnaire 2 years after surgery. All patients were recorded in the Swedish Cornea Registry, which provided clinical and demographic data for the study. Winsteps software v.3.91.0 (Winsteps.com, Beaverton, OR) was used to assess the fit of the Catquest-9SF data to the Rasch model. Results: Rasch analysis showed that Catquest-9SF applied to corneal transplant patients was unidimensional (infit range, 0.73-1.32; outfit range, 0.81-1.35), and therefore, measured a single underlying construct (visual disability). The Rasch model explained 68.5% of raw variance. The response categories of the 9-item questionnaire were ordered, and the category thresholds were well defined. Item difficulty matched the level of patients' ability (0.36 logit difference between the means). Precision in terms of person separation (3.09) and person reliability (0.91) was good. Differential item functioning was notable for only 1 item (satisfaction with vision), which had a differential item functioning contrast of 1.08 logit. Conclusions: Rasch analysis showed that Catquest-9SF is a valid instrument for measuring visual disability in patients who have undergone corneal transplantation primarily to improve vision.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Catquest-9SF validation, Corneal transplantation, patient-reported outcome measures
in
Cornea
volume
36
issue
9
pages
6 pages
publisher
Lippincott Williams and Wilkins
external identifiers
  • scopus:85027844031
  • pmid:28777777
  • wos:000407380100013
ISSN
0277-3740
DOI
10.1097/ICO.0000000000001255
language
English
LU publication?
yes
id
6fdd1e64-23ad-4239-8df0-21a399572291
date added to LUP
2017-09-01 14:58:25
date last changed
2018-01-07 12:17:17
@article{6fdd1e64-23ad-4239-8df0-21a399572291,
  abstract     = {<p>Purpose: Catquest-9SF is a 9-item visual disability questionnaire developed for evaluating patient-reported outcome measures after cataract surgery. The aim of this study was to use Rasch analysis to determine the responsiveness of Catquest-9SF for corneal transplant patients. Methods: Patients who underwent corneal transplantation primarily to improve vision were included. One group (n = 199) completed the Catquest-9SF questionnaire before corneal transplantation and a second independent group (n = 199) completed the questionnaire 2 years after surgery. All patients were recorded in the Swedish Cornea Registry, which provided clinical and demographic data for the study. Winsteps software v.3.91.0 (Winsteps.com, Beaverton, OR) was used to assess the fit of the Catquest-9SF data to the Rasch model. Results: Rasch analysis showed that Catquest-9SF applied to corneal transplant patients was unidimensional (infit range, 0.73-1.32; outfit range, 0.81-1.35), and therefore, measured a single underlying construct (visual disability). The Rasch model explained 68.5% of raw variance. The response categories of the 9-item questionnaire were ordered, and the category thresholds were well defined. Item difficulty matched the level of patients' ability (0.36 logit difference between the means). Precision in terms of person separation (3.09) and person reliability (0.91) was good. Differential item functioning was notable for only 1 item (satisfaction with vision), which had a differential item functioning contrast of 1.08 logit. Conclusions: Rasch analysis showed that Catquest-9SF is a valid instrument for measuring visual disability in patients who have undergone corneal transplantation primarily to improve vision.</p>},
  author       = {Claesson, Margareta and Armitage, W. John and Byström, Berit and Montan, Per and Samolov, Branka and Stenvi, Ulf and Lundström, Mats},
  issn         = {0277-3740},
  keyword      = {Catquest-9SF validation, Corneal transplantation,patient-reported outcome measures},
  language     = {eng},
  month        = {09},
  number       = {9},
  pages        = {1083--1088},
  publisher    = {Lippincott Williams and Wilkins},
  series       = {Cornea},
  title        = {Validation of Catquest-9SF-A Visual Disability Instrument to Evaluate Patient Function after Corneal Transplantation},
  url          = {http://dx.doi.org/10.1097/ICO.0000000000001255},
  volume       = {36},
  year         = {2017},
}