Development and Initial Validation of the MCL-PRO-CAT: A computerized adaptive test designed to measure multifocal contact lens performance from the patient's perspective.

Purpose: To create a valid and reliable computer-adaptive testing (CAT) tool for assessing Multifocal Contact Lens (MCL) performance in presbyopic individuals, ensuring high precision. The self-administered tool will initially be accessible online in Spanish.

Methods: Five steps were followed for the correct development of the instruments: item bank development, item refinement phase, item response theory calibration of the refined item bank, CAT simulations and design, and an initial validation study. A total of 1163 presbyopic patients were involved in the over-all study. Convergent validity was assessed by comparing results to the CLDQ-8 questionnaire, and repeatability assessment was performed two weeks after the initial completion.

Results: The final item bank consisted of 108 items assessing various relevant domains for MCL performance evaluation. The calibration study showed a person separation index of 4.69 and a reliability of 0.96 along with a measurement precision of 0.27. The final CAT distinguished between 16 levels of MCL performance by presenting an average of 10.61  ± 1.00 items per patient, with an average completion time of 3:04 ± 1:24 min. Signs of convergent validity showed a correlation of 0.73 and repeatability was assessed showing an intraclass Correlation Coefficient of 0.881 with a 95% Confidence Interval 0,815-0,924, and Limits of Agreement of  ± 1.07.

Conclusion: The MCL-PRO-CAT is a groundbreaking tool for evaluating MCL performance in presbyopic individuals. With automated scoring and fewer items, it was feasible, valid, and precise, enhancing clinical practicality.