Reliability and validation of the Dutch Achilles tendon Total Rupture Score

Patient-reported outcome measures (PROMs) have become a cornerstone for the evaluation of the effectiveness of treatment. The Achilles tendon Total Rupture Score (ATRS) is a PROM for outcome and assessment of an Achilles tendon rupture. The aim of this study was to translate the ATRS to Dutch and evaluate its reliability and validity in the Dutch population. A forward-backward translation procedure was performed according to the guidelines of cross-cultural adaptation process. The Dutch ATRS was evaluated for reliability and validity in patients treated for a total Achilles tendon rupture from 1 January 2012 to 31 December 2014 in one teaching hospital and one academic hospital. Reliability was assessed by the intraclass correlation coefficients (ICC), Cronbach's alpha and minimal detectable change (MDC). We assessed construct validity by calculation of Spearman's rho correlation coefficient with domains of the Foot and Ankle Outcome Score (FAOS), Victorian Institute of Sports Assessment-Achilles questionnaire (VISA-A) and Numeric Rating Scale (NRS) for pain in rest and during running. The Dutch ATRS had a good test-retest reliability (ICC = 0.852) and a high internal consistency (Cronbach's alpha = 0.96). MDC was 30.2 at individual level and 3.5 at group level. Construct validity was supported by 75 % of the hypothesized correlations. The Dutch ATRS had a strong correlation with NRS for pain during running (r = -0.746) and all the five subscales of the Dutch FAOS (r = 0.724-0.867). There was a moderate correlation with the VISA-A-NL (r = 0.691) and NRS for pain in rest (r = -0.580). The Dutch ATRS shows an adequate reliability and validity and can be used in the Dutch population for measuring the outcome of treatment of a total Achilles tendon rupture and for research purposes. Diagnostic study, Level I