Abstract:: Purpose: Despite an insidious onset without symptoms, patients with open–angle glaucoma (OAG) may experience difficulty with daily activities from. Purpose.: To investigate, using Rasch analysis, whether the item Glaucoma Quality of Life (GQL) forms a valid scale and to optimize. Abbreviation / Long Form: GQL / Glaucoma Quality of Life Questionnaire Abbreviation: GQL (>> Co-occurring Abbreviation). Long Form: Glaucoma.

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However, the binocular visual field test was not recorded in our study population. Items with fit statistics outside the acceptable range appear in bold. All the items of the GQL are scored on a five-category response scale of increasing difficulty and, therefore, have four thresholds. Quality of life in newly diagnosed glaucoma patients: However, removing these categories may lead to loss of valuable psychometric information when the instrument is used on patients with higher disability.

A comparison of the NEIVFQ25 and GQL questionnaires in Nigerian glaucoma patients

However, those items outside the range of 0. Reasonable mean-square fit values. This finding that QOL is reduced significantly in patients with mild glaucoma may also explain why the questionnaires used in this study NEIVFQ25 and GQL could not differentiate between moderate and mild glaucoma patients. Validity of the instrument was assessed by calculating correlation coefficient between the questionnaire score and traditional clinical measures that is, visual acuity and visual field.

Because visual acuity was not distributed normally, Spearman’s rank test was used to calculate correlation with the Glaucoma Activity Limitation-9 GAL-9 score. The development of an instrument to measure quality of vision: All 15 items fit the Rasch model within liberal infit 0. Impact of visual field loss on health-related quality of life in glaucoma: Poor targeting occurs because of items clustering at a certain point along the map, large gaps between items, and the higher or lower ability of the study population than the required level of ability to endorse the items.


Such a process is lengthy, time consuming, and does not guarantee avoidance of poor targeting.

Interval-level data not only provide a valid measurement, they enable the use of robust parametric statistics. The fact that there were an equal number of controls and cases as well as an equal number of cases with mild, moderate, or severe glaucoma strengthened the design of this study.

The Sickness Impact Profile: It might be a good idea to develop a new comprehensive instrument that addresses holistic issues such as treatment effects and the psychosocial impact of glaucoma or to develop a superior strategy in the form of item banking. Reduced QoL in these patients correlates strongly with reduced VA, severity of visual field defects and presence of binocular field defects.

Vision-related quality of life. Validity refers to the assessment of whether an instrument measures what it quuestionnaire to measure.

Results from a self-administered questionnaire. The removed items were tested for fit to the Rasch model to determine whether they could measure an additional construct, but the measurement precision was inadequate person separation, 1. Health Qual Life Outcomes. On the basis of MD in better eye, Patient-centred measurement in ophthalmology—a paradigm shift.

A comparison of the NEIVFQ25 and GQL-15 questionnaires in Nigerian glaucoma patients

Sociodemographic and Visual Characteristics of the Glaucoma Patients. Two optional utility questions rating general health and vision on a linear scale from the Gl-15 appendix were included in the questionnaire. Crossing the road Both statistics indicate how well items fit the underlying construct. On a scale from 15 no visual disability to 75 severe disability for all visual tasksthe mean GQL—15 summary score was None of the 15 items showed Questionnaife by age or sex Table 3.

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Creation of a nine-item version enabled unidimensional measurement with excellent psychometric attributes. Participants who had a history of glaucoma or unexplained blindness in questuonnaire first-degree relative or who were being managed for systemic illness were also excluded from the study.

The categories are used in the order intended, and each occupies a wide portion of the measurement scale. Validation of a questionnaire for comparing the tolerability of ophthalmic medications. The original GQL was developed in English. No further contrast exceeded 2.

Glare and dark adaptation subscale scores of the GQL increased with increasing severity of disease mild: Misfitting items should be removed to reduce noise and to optimize the psychometric properties of an instrument.

Quality of life in glaucoma and its relationship with visual function. Accessed August 7, Support Center Support Center. Individual items were scored. This was also the case for participants with severe and mild glaucoma. Given that MD and the nine-item questionnaire score person estimate in logit were normally distributed, Pearson’s correlation coefficient was used to calculate correlation between them.