Impact of Cataract Surgery on Psychological Well-Being and Economy: The SCOPE Study Protocol

To describe the study design and inter-observer agreement of study instruments for the impact of cataract surgery on the psychological well-being and economy (SCOPE) study, which aims to i) investigate the economic impact of cataract surgery among adults aged 40 and older in rural south India and ii) evaluate the effects of cataract surgery on visual function, dementia, mental health, and falls.

Participants aged ≥ 40 years with best-corrected distance visual acuity (BCVA) of <6/12 in both eyes and with bilateral, operable cataract will be enrolled. Both the groups (with and without cataract surgery) will be followed up at 3 and 12 months to assess the effect of cataract surgery on household and individual income after adjustment for age, gender, education, visual function, cognition, mental health, and fear of falls. To assess inter-rater reliability, continuous variables such as logarithmic minimum angle of resolution (logMAR) visual acuity (VA) values were categorized into visual impairment (VI) categories, and Cohen's Kappa was computed for all categorical measures, including logMAR VA, lens opacity, and all interview questionnaires.

Cohen's Kappa values for inter-rater agreement for logMAR VA, lens opacity, patient health questionnaire, Hindi Mental State Examination and Indian Visual Function Questionnaire were 0.655 (95%CI:0.558-0.792) to 0.939 (95%CI: 0.874-0.967); 0.700 (95%CI:0.547-0.742) to 0.938 (95%CI:0.871-0.969); 0.594 (95%CI:0.510-0.664) to 0.789 (95%CI:0.692-0.866); 0.846 (95%CI:0.812-0.859) to 0.872 (95%CI:0.849-0.932); and 0.507 (95%CI:0.430-0.585) to 0.507 (95%CI:0.404-0.607) respectively.

All questionnaires demonstrated reliability. SCOPE provides insights into the psychological, economic, and societal impacts of cataract surgery to inform healthcare policy and improve older adults' well-being.