Validity, Reliability, and Responsiveness of the Korean Version of American Academy of Orthopedic Surgeons Foot and Ankle Questionnaire

Abstract

The American Academy of Orthopaedic Surgeons Foot and Ankle Questionnaire (AFAQ) reflects patients' subjective disorder due to foot and ankle conditions. We evaluated the validity, reliability, and responsiveness of the Korean version of the AFAQ, after translation and transcultural adaptation of the original AFAQ into the Korean language. A total of 206 patients were enrolled, including 152 with chronic problems (experimental group) and 54 with acute problems (control group). We used the intraclass correlation coefficient to assess the test–retest reliability and Cronbach's α to assess internal reliability. Pearson's correlation coefficient was used to assess the criterion validity by correlating the Korean AFAQ scores with those from other validated scales (American Orthopaedic Foot and Ankle Society Hallux-Metatarsophalangeal-Interphalangeal scale, American Orthopaedic Foot and Ankle Society Ankle-Hindfoot scale, and visual analog scale for pain). To analyze discriminant validity, we evaluated the difference between the experimental and control groups using the Student t test. Of the 152 patients in the experimental group, 29 revisited our clinic postoperatively and repeated the Korean AFAQ. To analyze responsiveness, we used paired t tests to evaluate postoperative changes. In terms of test–retest reliability, the intraclass correlation coefficient ranged from 0.979 to 0.999. In terms of internal reliability, Cronbach's α was 0.528 for the stiffness and swelling subscale and greater than 0.7 for all other subscales. In terms of criterion validity, Pearson's correlation coefficient ranged from 0.492 to 0.699. The probability of the null hypothesis for discriminant validity and responsiveness was statistically significant (p < .001 and p = .021, respectively). These results showed that the Korean version of the AFAQ had the same concept and intention as the original version and is reliable, valid, and responsive.