Validity, reliability, and responsiveness of a self-reported foot and ankle score (SEFAS).
OBJECTIVE
A questionnaire was introduced by the New Zealand Arthroplasty Registry for use when evaluating the outcome of total ankle replacement surgery. We evaluated the reliability, validity, and responsiveness of the modified Swedish version of the questionnaire (SEFAS) in patients with osteoarthritis or inflammatory arthritis before and/or after their ankle was replaced or fused.


METHODS
The questionnaire was translated into Swedish and cross-culturally adapted according to a standardized procedure. It was sent to 135 patients with ankle arthritis who were scheduled for or had undergone surgery, together with the foot and ankle outcome score (FAOS), the short form 36 (SF-36) score, and the EuroQol (EQ-5D) score. Construct validity was evaluated with Spearman's correlation coefficient when comparing SEFAS with FAOS, SF-36, and EQ-5D, content validity by calculating floor and ceiling effects, test-retest reliability with intraclass correlation coefficient (ICC), internal consistency with Cronbach's alpha (n = 62), agreement by Bland-Altman plot, and responsiveness by effect size and standardized response mean (n = 37).


RESULTS
For construct validity, we correlated SEFAS with the other scores and 70% or more of our predefined hypotheses concerning correlations could be confirmed. There were no floor or ceiling effects. ICC was 0.92 (CI 95%: 0.88-0.95), Cronbach's alpha 0.96, effect size was 1.44, and the standardized response mean was 1.00.


CONCLUSIONS
SEFAS is a self-reported foot and ankle score with good validity, reliability and responsiveness, indicating that the score can be used to evaluate patients with osteoarthritis or inflammatory arthritis of the ankle and outcome of surgery.
Department of Orthopedics, Kalmar Hospital, Sweden. mariaco@ltkalmar.se
Maria
M
Cöster
Magnus K
MK
Karlsson
Jan-Åke
JÅ
Nilsson
Ake
A
Carlsson
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000843:Ankle Joint / Q000503:physiopathology / Q000601:surgery*; D001168:Arthritis / Q000453:epidemiology / Q000503:physiopathology / Q000601:surgery; D058737:Arthroplasty, Replacement, Ankle; D004185:Disability Evaluation; D005260:Female; D033023:Foot Joints / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007802:Language; D008297:Male; D008875:Middle Aged; D009520:New Zealand; D010003:Osteoarthritis / Q000453:epidemiology / Q000503:physiopathology / Q000601:surgery; D017060:Patient Satisfaction; D015203:Reproducibility of Results; D057566:Self Report / Q000592:standards*; D011795:Surveys and Questionnaires / Q000592:standards*; D013548:Sweden / Q000453:epidemiology; D016896:Treatment Outcome