Comments on: Reliability and Validity of a Chinese Version of the Lysholm Score and Tegner Activity Scale for Knee Arthroplasty

explained the process of criterion validation while ignoring the other validation process. The third concern regards the reliability test statistics used. The authors established test and retest reliability under relative reliability, with standard error of measurement and smallest detectable change under absolute reliability with omission of the Bland-Altman plot. However, the authors have added Bland-Altman plots for LS-C and TAS-C with the term, “constant variance” and not under the standard term “level of agreement” between the sessions. In addition, citation of Fig. 2 in the text is missing. The steps taken by the authors to translate the LS and TAS into Chinese are undoubtedly appreciated. However, based on the above logical concerns, and to comply with criteria for good measurement properties (5) and consensus-based standards for the selection of health measurement instruments (COSMIN) (6), the LS-C and TAS-C should be considered with caution before their clinical utilization.