Validation of the Portuguese version of the Oral Frailty Index-8 (Preprint)

BACKGROUND The concept of oral frailty has gained scientific and clinical relevance in recent years, and early detection and intervention can prevent its onset. The Oral Frailty Index-8 (OFI-8) was developed to assess community-dwelling older adults at risk for oral frailty. OBJECTIVE This study aims to investigate the psychometric validity of the OFI-8 in the Portuguese population, called OFI-8-PT, which may serve as a reference for future studies related to longevity and oral function. METHODS The present study included two main phases involving patients aged 60 years or older, Portuguese speakers, and those who consented to participate in the study. First, the researchers translated and cross-culturally adapted the original questionnaire to make it suitable for native Portuguese speakers. The translated tool was then assessed for psychometric validation, which consisted of test-retest reliability, internal consistency, construct validity, and gender invariance measurement. RESULTS A total of 159 older adults participated in the baseline survey, with almost equal numbers of males (79) and females (80). The OFI-8-PT demonstrated good reliability (Cronbach's alpha = 0.95) and construct validity (GFI = 0.96; CFI = 0.85; and, RMSEA = 0.05; 90% CI 0.00-0.09). The study found gender invariance, indicating that the OFI-8-PT is equally valid for males and females, and the tested-retest reliability of the OFI-8-PT was good, indicating consistent results over time. CONCLUSIONS Altogether, the study provides valuable insights into the psychometric validity of the OFI-8 PT questionnaire in the Portuguese population under study.