Psychometric Properties of the Five-Item Ultrashort Oral Health Impact Profile (OHIP5) in the Serbian Cultural Environment: A Cross-Sectional Study

<b>Background:</b> Dental patient-centred outcomes are essential in clinical practice and research. To enhance feasibility, Oral Health-Related Quality of Life (OHRQoL) instruments often need to reduce administration time. In Serbia, longer OHIP versions exist (OHIP-14, OHIP-EDENT), but the ultrashort OHIP-5 has not yet been available. Aim: This cross-sectional study aimed to translate, culturally adapt, and evaluate the psychometric properties of the five-item Serbian version of the Oral Health Impact Profile (OHIP5-Srb). <b>Materials and Methods:</b> The OHIP5-Srb was translated using a standard forward-backward procedure. Participants were recruited between June and September 2025 using a convenience sampling approach. Psychometric testing-including internal consistency, exploratory (EFA), confirmatory factor analysis (CFA), and convergent and known-groups validity-was conducted on 236 participants (mean age 47.4 years). Test-retest reliability was evaluated in 35 dental students, and responsiveness in 45 patients undergoing dental treatment. <b>Results:</b> Cronbach's alpha was 0.784, indicating adequate internal consistency. Test-retest reliability was excellent (mean ICC = 0.96; all inter-item correlations > 0.20). Convergent validity was supported by a strong negative correlation between OHIP5-Srb summary scores and a single-item measure of overall oral/dental health (Spearman's rho = -0.861, <i>p</i> < 0.01). Known-group validity was confirmed by significant differences between removable denture wearers and individuals with natural teeth (and/or fixed partial dentures), after adjusting for age, and between participants perceiving a need for dental treatment and those who did not. EFA indicated a one-factor structure explaining 55.1% of variance. The one-factor model was confirmed by CFA and showed good fit (χ² = 15.08, df = 5; CFI = 0.97; TLI = 0.94; RMSEA = 0.092; SRMR = 0.04). Responsiveness analysis demonstrated significant decreases in OHIP5-Srb scores following various dental treatments. <b>Conclusions:</b> The OHIP5-Srb is unidimensional, reliable, valid, and responsive. Its brevity and robust psychometric properties make it suitable for assessing self-perceived oral health-related quality of life in the Serbian urban population, particularly when minimizing respondent burden is critical.