Measuring glaucoma quality of life in an Asian population using item banking: psychometric evaluation and computerized adaptive testing simulations.

PURPOSE: To assess the psychometric properties of glaucoma-specific health-related quality of life (HRQoL) item banks (IBs), and explore their efficiency using computerized adaptive testing (CAT) simulations. METHODS: In this cross-sectional, clinical study, 300 Asian glaucoma patients answered 221 items within seven IBs: Ocular Comfort Symptoms (OS); Activity Limitation (AL); Lighting (LT); Mobility (MB); Glaucoma Management (GM); Psychosocial (PSY); and Work (WK). Rasch analysis was conducted to assess each IB's psychometric properties (e.g., item "fit" to the construct; unidimensionality) and a set of analytic performance criteria guiding decision making relating to retaining or dropping domains and items was employed. CAT simulations determined the mean number of items for 'high' and 'moderate' measurement precision (stopping rule: SEM 0.3 and 0.387, respectively). RESULTS: Participants' mean age was 67.2 ± 9.2 years (62% male; 87% Chinese). LT, MB, and GM displayed good psychometric properties overall. To optimize AL's psychometric properties, 16 items were deleted due to poor "fit", high missing data, item bias, low discrimination and/or a low clinical/patient importance rating. To resolve multidimensionality in PSY, we rehomed 16 items into a "Concern (CN)" domain. PSY and CN required further amendment, including collapsing of response categories, and removal of poorly functioning items (N = 7). Due to poor measurement precision, low applicability and high ceiling effect, low test information indices, and low item separation index the WK IB was not considered further. In CAT simulations on the final seven IBs (n = 182 items total), an average of 12.1 and 15.7 items per IB were required for moderate and high precision measurement, respectively. CONCLUSIONS: After reengineering our seven IBs, they displayed robust psychometric properties and good efficiency in CAT simulations. Once finalized, GlauCAT™-Asian may enable comprehensive assessment of the HRQoL impact of glaucoma and associated treatments.

Efficiency, Precision, Validity, and Reliability of GlauCAT-Asian Computerized Adaptive Tests in Measuring Glaucoma-Related Quality of Life.

Purpose: To determine the efficiency, precision, and agreement of GlauCAT-Asian and its corresponding validity and reliability. Methods: In this cross-sectional study, 219 participants (mean ± standard deviation age, 66.59 ± 8.61 years; 34% female) across the spectrum of glaucoma severity and 50 glaucoma suspects were recruited from glaucoma clinics in Singapore. Participants answered seven computerized adaptive testing (CAT) evaluations (Ocular Comfort, Activity Limitation, Lighting, Mobility, Concerns, Psychosocial, Glaucoma Management) and underwent eye examinations. Efficiency (mean number of items required for each CAT and time taken for CAT versus full item banks [IBs]), agreement (concordance between CATs and full IB person measures, henceforth referred to as scores), and precision (standard error of measurement [SE]) were evaluated. Other validity and reliability metrics were also assessed. Results: The mean number of items administered ranged from 9 (Mobility/Glaucoma Management) to 12 (Ocular Comfort). Compared to answering the full IBs, CATs provided an average time saving of 38.3% (range, 10% to 70.6% for Lighting and Activity Limitation, respectively). Agreement between scores obtained by CAT versus full IB was high (intracorrelation coefficient ≥0.75), as was precision of score estimates (mean SE range: 0.35 for Psychosocial to 0.29 for Mobility). Scores from Activity Limitation, Mobility, Lighting, and Concerns decreased significantly as glaucoma severity increased (criterion validity; P-trend <0.05). All tests displayed good convergent/divergent validity and test-retest reliability. Conclusions: GlauCAT-Asian provides efficient, precise, accurate, valid, and reliable measurement of the patient-centered impact of glaucoma. Translational Relevance: GlauCAT-Asian may provide a valuable clinical tool for ophthalmologists to monitor impact of disease progression and the effectiveness of therapies.

The development of a glaucoma-specific health-related quality of life item bank supporting a novel computerized adaptive testing system in Asia.

BACKGROUND: A glaucoma-specific health-related quality of life (HRQoL) item bank (IB) and computerized adaptive testing (CAT) system relevant to Asian populations is not currently available. We aimed to develop content for an IB focusing on HRQoL domains important to Asian people with glaucoma; and to compare the content coverage of our new instrument with established glaucoma-specific instruments. METHODS: In this qualitative study of glaucoma patients recruited from the Singapore National Eye Centre (November 2018-November 2019), items/domains were generated from: (1) glaucoma-specific questionnaires; (2) published articles; (3) focus groups/semi-structured interviews with glaucoma patients (n = 27); and (4) feedback from glaucoma experts. Data were analyzed using the constant comparative method. Items were systematically refined to a concise set, and pre-tested using cognitive interviews with 27 additional glaucoma patients. RESULTS: Of the 54 patients (mean ± standard deviation [SD] age 66.9 ± 9.8; 53.7% male), 67 (62.0%), 30 (27.8%), and 11 (10.2%) eyes had primary open angle glaucoma, angle closure glaucoma, and no glaucoma respectively. Eighteen (33.3%), 11 (20.4%), 8 (14.8%), 12 (22.2%), and 5 (9.3%) patients had no, mild, moderate, severe, or advanced/end-stage glaucoma (better eye), respectively. Initially, 311 items within nine HRQoL domains were identified: Visual Symptoms, Ocular Comfort Symptoms, Activity Limitation, Driving, Lighting, Mobility, Psychosocial, Glaucoma management, and Work; however, Driving and Visual Symptoms were subsequently removed during the refinement process. During cognitive interviews, 12, 23 and 10 items were added, dropped and modified, respectively. CONCLUSION: Following a rigorous process, we developed a 221-item, 7-domain Asian glaucoma-specific IB. Once operationalised using CAT, this new instrument will enable precise, rapid, and comprehensive assessment of the HRQoL impact of glaucoma and associated treatment efficacy.