title: 17-Italian Foot Function Index with numerical rating scale: development, reliability, and validity of a modified version of the original Foot Function Index.
abstract: BACKGROUND
  Clinical research quantifies symptoms and signs of pain.
  
  
  OBJECTIVE
  To develop a brief outcome measure to assess foot and ankle conditions, the psychometric properties of a modified version of the original Foot Function Index (FFI) were examined.
  
  
  METHODS
  Eighty-six subjects with musculoskeletal foot and ankle disorders were enrolled. The internal consistency and test-retest reliability were evaluated by using Cronbach's α and intraclass correlation coefficient (ICC). Criterion validity was tested by Pearson's correlation coefficient between 17 items of the Italian FFI (17-IFFI) and the Lower Extremity Functional Scale (LEFS). The responsiveness was calculated using the receiver operating characteristic curve (ROC).
  
  
  RESULTS
  Cronbach's Alpha was 0.95 (95% CI: 0.92, 0.99). The intra-interviewer and inter-interviewer ICC values were, respectively, 0.92 (95% CI: 0.88-10 0.96) and 0.90 (95% CI: 0.89-0.94). Correlations between the 17-IFFI scores and the LEFS scores were -0.564 and -0.456 at the initial and at the end of the treatment, respectively. The ROC analysis revealed an area under the curve of 0.732 (95% CI: 0.61-0.82) for the 17-IFFI and 0.633 (95% CI: 0.52-0.71) for the LEFS score.
  
  
  CONCLUSIONS
  The 17-IFFI is a reliable and valid scale and we recommend its application to evaluate the effectiveness of a treatment in patients with musculoskeletal foot and ankle disorders.
authors: Board of Physical Medicine and Rehabilitation, Department of Orthopaedic Science, "Sapienza" University, Rome, Italy. Electronic address: teresa.venditto@hotmail.it.
authors: Teresa
authors: T
authors: Venditto
authors: Board of Physical Medicine and Rehabilitation, Department of Orthopaedic Science, "Sapienza" University, Rome, Italy.
authors: Lucrezia
authors: L
authors: Tognolo
authors: Board of Physical Medicine and Rehabilitation, Department of Orthopaedic Science, "Sapienza" University, Rome, Italy; Physical Medicine Rehabilitation Center Nomentana Hospital, Fontenuova, Rome, Italy.
authors: Rosaria Sabrina
authors: RS
authors: Rizzo
authors: Rheumatology, Department of Internal Medicine and Medical Specialities, Sapienza University of Rome, Italy.
authors: Cristina
authors: C
authors: Iannuccelli
authors: Physical Medicine and Rehabilitation Unit, Azienda Policlinico Umberto I, Rome, Italy.
authors: Luca
authors: L
authors: Di Sante
authors: Department of Orthopaedic Surgery, Policlinico Umberto I, University La Sapienza, Rome, Italy.
authors: Mauro
authors: M
authors: Trevisan
authors: Physical Medicine and Rehabilitation Unit, S. Pietro Fatebenefratelli Hospital, Rome, Italy.
authors: Francesca Romana
authors: FR
authors: Maggiolini
authors: Physical Medicine and Rehabilitation Unit, Azienda Policlinico Umberto I, Rome, Italy; Board of Physical Medicine and Rehabilitation, Department of Orthopaedic Science, "Sapienza" University, Rome, Italy.
authors: Valter
authors: V
authors: Santilli
authors: Physical Medicine and Rehabilitation Unit, Azienda Policlinico Umberto I, Rome, Italy.
authors: Francesco
authors: F
authors: Ioppolo
mesh_terms: D000328:Adult; D000368:Aged; D000843:Ankle Joint; D005260:Female; D005534:Foot Diseases / Q000503:physiopathology* / Q000534:rehabilitation; D006801:Humans; D007558:Italy; D007592:Joint Diseases / Q000503:physiopathology* / Q000534:rehabilitation; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D063868:Patient Outcome Assessment; D011594:Psychometrics; D012372:ROC Curve; D020127:Recovery of Function / Q000502:physiology*; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires
keywords: Cross cultural adaptation; Foot injuries; Italian Foot Function Index