Validation of "Victorian institute of sports assessment for patellar tendons" in patellofemoral pain: Reliability, interpretability and feasibility study.

Abstract

Background: The Victorian institute of sports assessment for patellar tendons questionnaire (VISA-P), a valid tool for patellar tendinopathy, has been used for patellofemoral pain (PFP).

Aim: To validate VISA-P in PFP.

Methods: Study of validity, responsiveness and feasibility following COSMIN. Inclusion criteria: Subjects with PFP, aged 18 to 55. Agreement among 10 experts on the relevance and clarity of each item using Aiken's V coefficient determined content validity. An exploratory factorial analysis established structural validity. The correlation of VISA-P with knee injury and osteoarthritis outcome score for PFP and Osteoarthritis (KOOS-PF) and Kujala patellofemoral score (KPS; specific for PFP) analyzed the construct validity. Internal consistency was calculated with Cronbach's α and test-retest reliability with the intraclass correlation coefficient (ICC). Feasibility considered the subjects' self-completion time.

Results: The sample consisted of 103 knees from 73 subjects (47 female/26 male; aged 34.9 ± 13 SD). The items were relevant and clear, with the exception of item-8, which didn't reach an acceptable level of agreement on clarity. Exploratory factorial analysis found a 2-factor solution, which explained 63.48% of the variance. VISA-P achieved a strong and significant correlation with KOOS-PF (Spearman rho = 0.826; P < 0.001) and KPS (Spearman rho = 0.771; P < 0.001). The questionnaire showed adequate reliability (Cronbach's α: 0.752; ICC: 0.934; P < 0.0001; 95%CI: 0.902-0.955). The mean self-completion time was 232 ± 0.52 SD seconds.

Conclusion: VISA-P proved to be valid and reliable to functionally assess PFP and/or chondromalacia patella. VISA-P is a feasible tool in the clinical and research environment, quick and easy to complete.