Evaluating patient-reported outcome measures (PROMs) for clinical trials and clinical practice in adult patients with uveitis or scleritis: a systematic review

Patient reported outcome measures (PROMs) capture impact of disease and treatment on quality of life, and have an emerging role in clinical trial outcome measurement. This study included a systematic review and quality appraisal of PROMs developed or validated for use in adults with uveitis or scleritis. We searched MEDLINE, EMBASE, PsycINFO, CINAHL and grey literature sources, to 5 November 2021. We used established quality criteria to grade each PROM instrument in multiple domains from A (high quality) to C (low quality), and assessed content development, validity, reliability and responsiveness. For instruments developed using classic test theory-based psychometric approaches, we assessed acceptability, item targeting and internal consistency. For instruments developed using Item Response Theory (IRT) (e.g. Rasch analysis), we assessed response categories, dimensionality, measurement precision, item fit statistics, differential item functioning and targeting. We identified and appraised four instruments applicable to certain uveitis types, but none for scleritis. Specifically, the National Eye Institute Visual Function Questionnaire-25 (NEI-VFQ), a 3-part PROM for Birdshot retinochoroiditis (Birdshot Disease & Medication Symptoms Questionnaire [BD&MSQ], the quality of life (QoL) impact of Birdshot Chorioretinopathy [QoL BCR], and the QoL impact of BCR medication [QoL Meds], the Kings Sarcoidosis Questionnaire (KSQ), and a PROM for cytomegalovirus retinitis. These instruments had limited coverage for these heterogeneous conditions, with a focus on very rare subtypes. Psychometric appraisal revealed considerable variability between instruments, limited content development, and only one developed using Item Response Theory. In conclusion, there are few validated PROMs for patients with uveitis and none for scleritis, and existing instruments have suboptimal psychometric performance. We articulate why we do not recommend their inclusion as clinical trial outcome measures for drug licensing purposes, and highlight an unmet need for PROMs applicable to uveitis and scleritis.