Development of the Italian version of the Anterior Cruciate Ligament Quality of Life (ACL-QoL): A validity and reliability study.

Abstract

To translate the anterior cruciate ligament quality of life (ACL-QoL) into Italian and evaluate its measurement properties for use following both surgical and nonsurgical management for anterior cruciate ligament (ACL) injury. The ACL-QoL was translated into Italian following international guidelines and was administered to 148 subjects with ACL injury (75.7% male, mean age: 27.8 ± 8.1 years, mean time after injury: 2.9 ± 3.6 years) together with other measurement instruments. Its structural validity, internal consistency, test-retest reliability, measurement error and construct validity were assessed following the COSMIN recommendations. The confirmatory factor analysis partially fit to the five-factor model (standardised root mean square residual = 0.059, comparative fit index = 0.943, Tucker Lewis index = 0.931; root mean square error of approximation = 0.065). Each subscale demonstrated adequate internal consistency (Cronbach's α ≥ 0.70). Test-retest reliability (N = 63) was good to excellent (intraclass correlation coefficients > 0.80 for all subscales). The standard error of measurement varied between 6.8 and 11.6 points across each subscale, and the minimum detectable change ranged from 18.8 to 32.1 points. Moreover, over 60% of our hypotheses testing were met, underscoring the moderate and satisfactory construct validity. Italian versions of the ACL-QoL demonstrate adequate internal consistency, good to excellent test-retest reliability and moderate to satisfactory construct validity, making it suitable for the assessment of primarily male individuals with ACL injuries undergoing both surgical and nonsurgical management and had completed rehabilitation several years before. However, the measurement error should be high, while the structural validity shows room for improvement and further deep exploration for cause of misfit is necessary. Level II.