Performance of the Achilles Tendon Total Rupture Score Over Time in a Large National Database: Development of an Instruction Manual for Accurate Use.

Abstract

The Achilles tendon Total Rupture Score (ATRS) is a commonly used patient-reported outcome measure for patients with an acute Achilles tendon rupture. The score consists of 10 questions, the last 3 of which include activities that some patients cannot or do not do. No instruction manual has been developed for the ATRS. The purpose was to evaluate the ATRS at 4, 12, and 24 months after a rupture. The hypothesis was that the results at 4 months would be inconsistent when compared with the results at 1 year and 2 years. We also aimed to develop a manual that explains how to use the ATRS. Cohort study (Diagnosis); Level of evidence, 3. This was a mixed-methods study. The first section was a registry study, where prospectively collected data were analyzed. Data were collected 4, 12, and 24 months after rupture. The original score based on 10 items was compared with a score based on the first 7 items adjusted to the same scale as the original score. Density plots and scatterplots were made and differences between the scores were tested using the Mann-Whitney <i>U</i> test. The second section of the study consisted of discussions among the authors, which resulted in a manual for the ATRS. In total, 2790 complete ATRSs were included. The 7-item score significantly overestimated the value of the 10-item score at all time points (<i>P</i> < .001), but only at 4 months was the difference clinically relevant (9.7 points). When the ATRS is used for short-term evaluation, there is a risk of results being inconsistent because of the last 3 questions. A manual explaining how to use the ATRS was therefore developed. We recommend that the full ATRS together with the manual should be used in future research rather than eliminating the 3 last questions.