Establishment of the Patient Acceptable Symptom State (PASS) for the Achilles Tendon Total Rupture Score in a Swedish Population

Abstract

Background: As the use of patient-reported outcome measures (PROMs) is increasing in orthopaedic research, there is also a growing need for a standardized interpretation of these scores, such as the Patient Acceptable Symptom State (PASS), defined as the value beyond which patients consider themselves well. The Achilles tendon Total Rupture Score (ATRS) is the only PROM specific for Achilles tendon ruptures. Purpose: To establish the PASS for the ATRS in a Swedish population. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Patients treated for an acute Achilles tendon rupture at a single institution in Sweden (injured between July 1, 2018, and December 31, 2020) were asked to participate in this study. The patients completed a questionnaire consisting of the ATRS and an anchor question: “How satisfied are you with the result of your treatment?” Receiver operating characteristic curve analysis was performed to calculate the PASS threshold for a positive response to the anchor question. Results: Of 516 eligible patients, 316 (61%) were included. The time from injury to completion of the questionnaire ranged from 12 to 27 months. The PASS threshold for the ATRS was found to be 75. The median ATRS of all patients was 80; 66% of patients reached an ATRS ≥75. Overall, 79% of patients were satisfied with the results of their treatment. Conclusion: The estimated PASS for the ATRS was 75 in the general Swedish population at 12 to 27 months after an acute Achilles tendon rupture.