Psychometric Evaluation of Glaucoma Quality of Life Item Banks (GlauCAT) and Initial Assessment Using Computerized Adaptive Testing

Abstract

Purpose To evaluate the psychometric properties of glaucoma-specific quality of life (QoL) item banks (GlauCAT) and assess their performance using computerized adaptive testing (CAT) simulations. Methods In this cross-sectional study, 293 participants with glaucoma (mean age ± SD, 70.7 ± 13.2 years; 45% female) answered 342 items in 12 QoL item banks (IBs): Activity Limitation (AL); Driving (DV); Convenience (CV); Economic (EC); Emotional (EM); General Symptoms (GS); Health Concerns (HC); Lighting (LT); Mobility (MB); Ocular Surface Symptoms (OS); Social (SC); and Visual Symptoms (VS). These IBs were assessed using Rasch analysis, and CAT simulations with 1000 simulated respondents were utilized to determine the average number of items to be administered to achieve moderate and high precision levels. Results The AL, DV, EM, HC, LT, MB, EC, OS, SC, and VS IBs required relatively minor amendments to achieve satisfactory psychometric fit. To resolve multidimensionality, we split CV into Treatment Convenience (TCV) and General Convenience (GCV). Due to poor measurement precision, the GS IB was not pursued further. This resulted in 12 total IBs. In CAT simulations, an average of 3.7 and 7.3 items per IB were required to attain measurement at moderate and high precision, respectively. Conclusions Following rigorous psychometric assessment, we developed 12 valid glaucoma-specific QoL domains that can obtain highly precise person measure estimates using a small number of items. Translational Relevance GlauCAT will enable researchers and clinicians to quickly and comprehensively assess the impact of glaucoma and its associated interventions across a range of QoL domains.

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

“…This affected CAT efficiency in the highest ability ‘bins’ (D9-10), with more items needed on average to provide a score estimate. Similar targeting issues were observed in the GlauCAT™-Western instrument, where 11/12 IBs lacked items targeted to very high performers [ 17 ]. The poor targeting may be due to the lack of VI in our sample, with most people with glaucoma having good VA until late-stage disease [ 42 , 43 ].…”

“…The PSY domain needed to be split to resolve multidimensionality, which is not unexpected given that it contained items relating to ‘concerns’ (e.g., falling), social life (e.g., becoming socially isolated), and emotional reactions (e.g., feel frustrated). Indeed, sister instruments for diabetic retinopathy (RetCAT™ [ 13 , 41 ]) and GlauCAT™-Western [ 17 ] both have > 1 domain measuring the psychosocial aspects of HRQoL. In a head-to-head comparison of the two GlauCAT instruments, the newly developed Asian version is more compact, comprising only seven domains compared to 12.…”

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

“…Our team has previously developed, 11 , 12 validated, 13 and successfully implemented 14 , 15 12 glaucoma-specific CATs for Western populations (GlauCAT). To account for differences in disease pathophysiology, lifestyles, health care systems, and illness perceptions between patients with glaucoma in Western and Asian countries, we have also subsequently developed a seven-domain, 182-item IB to assess the HRQoL impact of glaucoma and associated treatments in Asian patients (GlauCAT- Asian).…”