Kovac, Bojan (52563978600)Bojan (52563978600)KovacVukosavljevic, Miroslav (24330345200)Miroslav (24330345200)VukosavljevicDjokic Kovac, Jelena (52563972900)Jelena (52563972900)Djokic KovacResan, Mirko (26023596700)Mirko (26023596700)ResanTrajkovic, Goran (9739203200)Goran (9739203200)TrajkovicJankovic, Janko (15022715100)Janko (15022715100)JankovicSmiljanic, Milena (56841421200)Milena (56841421200)SmiljanicGrgurevic, Anita (12780453700)Anita (12780453700)Grgurevic2025-06-122025-06-122015https://doi.org/10.1186/s12955-015-0330-5https://www.scopus.com/inward/record.uri?eid=2-s2.0-84941556907&doi=10.1186%2fs12955-015-0330-5&partnerID=40&md5=d0f90fd92597d0a504814132de597a12https://remedy.med.bg.ac.rs/handle/123456789/8094Purpose: To test the validity and reliability of the Serbian version of the interviewer-administered format of the National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25). Methods: The Serbian version of NEI VFQ-25 was translated in accordance with standard methods that have been adopted internationally. In order to assess the reliability and validity of the translated NEI VFQ-25, we used a sample of 105 patients with four different chronic ocular diseases. Cronbach's alpha coefficient was used to assess internal consistency for each subscale. To assess test-retest reliability, intraclass correlation coefficients were used. The test-retest data were obtained from clinically stable patients with age-related cataracts, in surveys performed 2weeks apart. Rasch analysis was also applied as a modern methods of psychometric assessment of the questionnaire. Results: Four groups of patients were studied and the most prevalent were patients with cataract 40 (38.1%), followed by diabetic retinopathy 31 (29.5%), age related macular degeneration 22 (21.0%) and glaucoma 12 (11.4%). The overall index score on the NEI VFQ-25 ranged from 65.3 to 67.8 with a mean of 67.4±15.0. Cronbach's alpha coefficient (index of internal consistency reliability) ranged from 0.643 to 0.889 for the subscales. Evaluation of the validity of the Serbian version of NEI VFQ-25 is presented in the multi-trait-multi-method matrix and all items passed the convergent and discriminant validity tests. Rasch analysis showed a good measurement precision, but also demonstrated misfitting items and multidimensionality of the questionnaire. Conclusion: Although traditional validation method indicates that the Serbian version of NEI VFQ-25 is a valid and reliable instrument for the assessment of vision specific QoLin Serbian populations aged 40years or older, Rasch analysis revealed a substantial weakness of the questionnaire that should be taken into consideration when interpreting the results. © 2015 Kovac et al.