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Validation of Electronic Foot Function Index in Patients with Foot and Ankle Disease: A Randomized, Prospective Multicenter Study
J Korean Foot Ankle Soc 2019;23:24-30
Published online March 15, 2019;
© 2019 Korean Foot and Ankle Society

Dong Yeon Lee, Yu Mi Kim*, Jun Hyung Lee*, Jin Kim*, Ji-Beom Kim, Bom Soo Kim, Gi Won Choi§, Sang Gyo Seo, Jun Beom Kim, Se-Jin Park**, Yoon-Chung Kim††, Young Rak Choi‡‡, Dong-Oh Lee§§, Jae-Ho Cho∥∥, Dong-Il Chun¶¶, Hyong Nyun Kim***, Jae-Yong Park†††

Department of Orthopedic Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, *Department of Orthopedic Surgery, Wonkwang University Sanbon Hospital, Wonkwang University School of Medicine, Gunpo,
Seoul Foot and Ankle Center, Dubalo Orthopedic Clinic, Seoul, Department of Orthopedic Surgery, Inha University School of Medicine, Incheon, §Department of Orthopedic Surgery, Korea University Ansan Hospital, Ansan, Department of Orthopedic Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Department of Orthopedic Surgery, Sun General Hospital, Daejeon,
**Department of Orthopedic Surgery, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul,
††Department of Orthopedic Surgery, St. Vincent’s Hospital, College of Medicine, The Catholic University of Korea, Suwon,
‡‡Department of Orthopedic Surgery, CHA Bundang Medical Center, CHA University School of Medicine, Seongnam, §§Department of Orthopedic Surgery, Myongji Hospital, Goyang, ∥∥Department of Orthopedic Surgery, Chuncheon Sacred Heart Hospital, College of Medicine, Hallym University, Chuncheon, ¶¶Department of Orthopedic Surgery, Seoul Hospital, Soonchunhyang University College of Medicine, ***Department of Orthopedic Surgery, Kangnam Sacred Heart Hospital, College of Medicine, Hallym University, Seoul,
†††Department of Orthopedic Surgery, Hallym University Sacred Heart Hospital, Anyang, Korea
Correspondence to: Yu Mi Kim, Department of Orthopedic Surgery, Wonkwang University Sanbon Hospital, Wonkwang University School of Medicine, 327 Sanbon-ro, Gunpo 15865, Korea, Tel: 82-31-390-2224, Fax: 82-31-398-2223, E-mail:
Received January 24, 2019; Revised March 7, 2019; Accepted March 8, 2019.
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Purpose: To evaluate the efficiency of the electronic foot function index (eFFI) through a prospective, random based, multi-institutional study.
Materials and Methods: The study included 227 patients ranging in age from 20 to 79 years, visited for surgery in different 15 institutes, and agreed to volunteer. The patients were assigned randomly into a paper-based evaluated group (n=113) and tablet-based evaluated group (n=114). The evaluation was done on the day of hospital admission and the method was changed on the second day of surgery and re-evaluated. PADAS 2.0 ( was used as an electronic evaluation program.
Results: There were no differences in age and sex in both groups. The intraclass correlation coefficient (ICC) evaluation revealed an eFFI ICC of 0.924, showing that both results were similar. The evaluation time was shorter in the tablet-based group than the paper-based group (paper vs tablet, 3.7±3.8 vs 2.3±1.3 minutes). Thirty-nine patients (17.2%) preferred to use paper and 131 patients (57.7%) preferred the tablet. Fifty-seven patients (25.1%) found both ways to be acceptable.
Conclusion: eFFI through tablet devices appears to be more constant than the paper-based program. In addition, it required a shorter amount of time and the patients tended to prefer the tablet-based program. Overall, tablet and cloud system can be beneficial to a clinical study.
Keywords : Questionnaire, Foot function index, Patient-reported outcome measures

June 2019, 23 (2)