Validation of the American College of Foot and Ankle Surgeons Scoring Scales

The American College of Foot and Ankle Surgeons (ACFAS) assembled a task force to develop a scoring scale that could be used by the membership and practitioners-at-large. The original publication that introduced the scale focused primarily on use of the scale and provided only brief background on the development of the health measurement instrument. Concerns regarding the validity and reliability of the scale were raised within the professional community, and ACFAS assembled a task force to address these concerns. The purpose of this article is to address the issues raised by reporting the detailed methods used in the development of the ACFAS Scoring Scales. The authors who constitute this task force reviewed the body of work previously conducted and applied standards that serve to evaluate the scoring scale for: 1) validity, 2) reliability, and 3) sensitivity to change. The results showed that a systematic and comprehensive approach was used in the development of the scoring scales, and the task force concluded that the statistical methods and instrument development process for all 4 modules of the scoring scales were conducted in an appropriate manner. Furthermore, modules 1 and 2 have been rigorously assessed and the elements of these modules have been shown to meet standards for validity, reliability, and sensitivity to change.