Theodoros P Marakis1, Chrysanthi Koutsandrea2, Klio I Chatzistefanou2, Yannis Tountas3. 1. First Department of Ophthalmology, University of Athens Medical School, Athens, Greece. theomarakis@yahoo.gr. 2. First Department of Ophthalmology, University of Athens Medical School, Athens, Greece. 3. Center for Health Services Research, Department of Hygiene and Epidemiology, University of Athens Medical School, Athens, Greece.
Abstract
PURPOSE: To assess the psychometric properties of the Greek Macular Disease-Dependent Quality of Life Questionnaire (MacDQoL). METHODS: The MacDQoL was translated in Greek and administered to 191 patients with neovascular age-related macular degeneration (AMD). To assess validity, all patients completed the Greek SF-12 health survey and underwent vision measurements. For test-retest reliability, a subset of twenty participants completed the MacDQoL twice, 2 weeks apart. Responsiveness was assessed on 102 patients who completed the MacDQoL at a follow-up visit, 1 year later. Rasch analysis was used to assess the Greek MacDQoL's response category functioning, precision, unidimensionality, targeting and differential item functioning. RESULTS: Internal and test-retest reliability of the average weighted impact (AWI) was 0.952 and 0.97, respectively. Test-retest reliability of MacDQoL items ranged from 0.78 to 0.99. Principal component analysis revealed three subscales (activities, embarrassment and family life), which were also confirmed by confirmatory factor analysis. Rasch analysis revealed poor functionality of response categories and that was resolved by collapsing response categories and using the impairment scores only. In terms of convergent validity, the AWI and revised MacDQoL scales showed significant correlations with SF-12 summary scales (ρ = 0.21-0.30) and vision assessments (ρ = 0.31-0.46). Poorer AMD-related QoL at 1-year follow-up was associated with deterioration in distance visual acuity and worse eye near visual acuity. CONCLUSIONS: The Greek MacDQoL is a reliable, valid and sensitive to change in vision instrument for assessing AMD patients' perceptions of QoL. However, Rasch analysis revealed that its multiplicative rating scale is flawed. Scientific measurement was restored with a number of revisions to the questionnaire.
PURPOSE: To assess the psychometric properties of the Greek Macular Disease-Dependent Quality of Life Questionnaire (MacDQoL). METHODS: The MacDQoL was translated in Greek and administered to 191 patients with neovascular age-related macular degeneration (AMD). To assess validity, all patients completed the Greek SF-12 health survey and underwent vision measurements. For test-retest reliability, a subset of twenty participants completed the MacDQoL twice, 2 weeks apart. Responsiveness was assessed on 102 patients who completed the MacDQoL at a follow-up visit, 1 year later. Rasch analysis was used to assess the Greek MacDQoL's response category functioning, precision, unidimensionality, targeting and differential item functioning. RESULTS: Internal and test-retest reliability of the average weighted impact (AWI) was 0.952 and 0.97, respectively. Test-retest reliability of MacDQoL items ranged from 0.78 to 0.99. Principal component analysis revealed three subscales (activities, embarrassment and family life), which were also confirmed by confirmatory factor analysis. Rasch analysis revealed poor functionality of response categories and that was resolved by collapsing response categories and using the impairment scores only. In terms of convergent validity, the AWI and revised MacDQoL scales showed significant correlations with SF-12 summary scales (ρ = 0.21-0.30) and vision assessments (ρ = 0.31-0.46). Poorer AMD-related QoL at 1-year follow-up was associated with deterioration in distance visual acuity and worse eye near visual acuity. CONCLUSIONS: The Greek MacDQoL is a reliable, valid and sensitive to change in vision instrument for assessing AMDpatients' perceptions of QoL. However, Rasch analysis revealed that its multiplicative rating scale is flawed. Scientific measurement was restored with a number of revisions to the questionnaire.
Authors: Caroline B Terwee; Sandra D M Bot; Michael R de Boer; Daniëlle A W M van der Windt; Dirk L Knol; Joost Dekker; Lex M Bouter; Henrica C W de Vet Journal: J Clin Epidemiol Date: 2006-08-24 Impact factor: 6.437
Authors: Fotis Topouzis; Anne L Coleman; Alon Harris; Eleftherios Anastasopoulos; Fei Yu; Archimidis Koskosas; Theofanis Pappas; Leonidas Mavroudis; M Roy Wilson Journal: Am J Ophthalmol Date: 2006-09-05 Impact factor: 5.258
Authors: Robert P Finger; Eva Fenwick; Konrad Pesudovs; Manjula Marella; Ecosse L Lamoureux; Frank G Holz Journal: Ophthalmology Date: 2012-09-08 Impact factor: 12.079
Authors: Rupert R A Bourne; Jost B Jonas; Seth R Flaxman; Jill Keeffe; Janet Leasher; Kovin Naidoo; Maurizio B Parodi; Konrad Pesudovs; Holly Price; Richard A White; Tien Y Wong; Serge Resnikoff; Hugh R Taylor Journal: Br J Ophthalmol Date: 2014-03-24 Impact factor: 4.638
Authors: Jan Mitchell; James S Wolffsohn; Alison Woodcock; Stephen J Anderson; Carolyn V McMillan; Timothy Ffytche; Martin Rubinstein; Winfried Amoaku; Clare Bradley Journal: Health Qual Life Outcomes Date: 2005-04-14 Impact factor: 3.186
Authors: Jo Lane; Emilie M F Rohan; Faran Sabeti; Rohan W Essex; Ted Maddess; Amy Dawel; Rachel A Robbins; Nick Barnes; Xuming He; Elinor McKone Journal: PLoS One Date: 2018-12-31 Impact factor: 3.240