Translation, Validity, and Reliability of the Dutch Anterior Cruciate Ligament–Quality of Life Questionnaire

Abstract

Background: The Anterior Cruciate Ligament–Quality of Life (ACL-QoL) questionnaire is a valid and reliable injury-specific instrument to assess the impact of an ACL rupture on the daily life of a patient. Purpose: To translate the ACL-QoL into Dutch (ACL-QoL-NL) and to study its psychometric properties in patients with an ACL rupture. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: The original ACL-QoL questionnaire was translated from English to Dutch according to international guidelines. The study population consisted of 122 patients with a confirmed ACL rupture who completed the ACL-QoL-NL as well as 4 questionnaires: the International Knee Documentation Committee subjective score, Knee injury and Osteoarthritis Outcome Score, 36-item Short Form Health Survey, and Lysholm Knee Score. We determined the internal consistency, construct validity, and prevalence of floor and ceiling effects of the ACL-QoL-NL total score as well as its 5 subscales. To determine test-retest reliability, we analyzed the data of 68 patients who had a stable knee condition and who completed the ACL-QoL-NL a second time after a 2-week interval. Results: The confirmatory factor analysis showed that the original structure of the ACL-QoL-NL was confirmed, except for 4 of 31 items. Internal consistency of the total scale and all 5 subscales was good. More than 75% of the predefined hypotheses on the correlations between the ACL-QoL-NL and the 4 questionnaires were met, indicating good construct validity. No significant floor or ceiling effects were observed. Test-retest reliability was good, and no systematic bias between test and retest was found. Standard error of measurement for the total score was 4.8 points out of 100, and the smallest detectable changes at the group and individual levels were 1.6 and 13.2 points, respectively. Conclusion: The ACL-QoL-NL questionnaire was successfully translated from English to Dutch and demonstrated good internal consistency, validity, and reliability, with no presence of floor or ceiling effects.