Minimal clinically important differences in Toronto Extremity Salvage Score for patients with lower extremity sarcoma

Abstract

Background: The Toronto Extremity Salvage Score (TESS) is the most widely used patient-reported outcome measure for orthopaedic oncology patients. However, minimal clinically important differences (MCIDs) in the TESS have not been analyzed. The aim of this study was to define the MCIDs of TESS in patients with lower extremity sarcoma.

Methods: A total of 85 patients were investigated to calculate the MCIDs for TESS. Three different methods were used: 1) distribution-based methods based on one-half of the standard deviation and standard error of measurement (SEM) at the baseline, 2) anchor-based and receiver operating characteristic (ROC) analysis, and 3) anchor-based using Akaike's Information Criterion (AIC) analysis.

Results: The MCIDs at 6 months were 4.9-7.8 by distribution-based methods and 4.3-4.4 by anchor-based methods. The MCIDs at 12 months were 4.0-6.9 by distribution-based methods and 10.6-11.6 by anchor-based methods.

Conclusions: We calculated MCID values for the TESS based on distribution- and anchor-based approaches. Our results seem reasonable since MCIDs calculated by the different approaches had similar values. This knowledge will enable clinicians to identify meaningful functional improvements in sarcoma patients.