Reliability and validity of the Persian version of the Victorian Institute of Sport Assessment-Patella (VISA-P) Questionnaire.

Abstract

Patellar tendinopathy symptoms and functional limitations should be evaluated using validated, language-specific assessment tools. Cultural adaptation of these tools can improve their psychometric properties across languages. The VISA-P questionnaire is the only condition-specific tool for measuring symptom severity, but a validated Persian version is not available. To translate, culturally adapt, and evaluate the psychometric properties of the VISA-P questionnaire for use among Persian-speaking athletes. Case-control observational study with a test-retest subgroup; Level of evidence, 3. The VISA-P was translated into Persian following international guidelines: forward translation, synthesis, back-translation, expert review, pretesting, and validation. Sixty Persian-speaking athletes (30 with patellar tendinopathy, 30 healthy controls) participated in this cross-sectional study. Psychometric evaluation followed COSMIN standards assessing structural validity (exploratory factor analysis), construct validity (Spearman correlation with the Blazina classification), known-groups validity (comparison between symptomatic and healthy athletes using the Mann-Whitney U test)), internal consistency (Cronbach's α), and test-retest reliability (ICC over 24-48 h). Face validity, feasibility, and interpretability were also assessed. The VISA-P-Pr demonstrated good face and content validity. Factor analysis revealed a two-factor structure explaining 87.1% of variance with strong item loadings. Construct validity was supported by a strong negative correlation with the Blazina classification (r_s = -0.75, p < .001), and known-groups validity showed significantly lower scores in athletes with patellar tendinopathy compared to healthy controls (median 65.0 vs 98.5, p < .001). Test-retest reliability was excellent in the tendinopathy group (ICC = 0.91) with good internal consistency across both assessments (Cronbach's α = 0.88 and 0.89). The VISA-P-Pr is a reliable and valid instrument with psychometric properties comparable to the original VISA-P, suitable for clinical and research use among Persian-speaking athletes.