The MOXFQ patient-reported questionnaire: assessment of data quality, reliability and validity in relation to foot and ankle surgery.

Previously validated for hallux valgus surgery, the Manchester-Oxford Foot Questionnaire (MOXFQ) is here evaluated for use with different regions of the foot and ankle. The study recruited 671 consecutive patients (87.8% of those eligible), mean age 52.8 years, 64% female, who completed the MOXFQ and SF-36 general health survey before foot or ankle surgery. Surgeons completed the American Orthopaedic Foot & Ankle Society (AOFAS) scales and indicated that the patients' main regions for surgery were: Hallux 210 (31.3%), Lesser toes 119 (17.7%), Mid foot 22 (3.3%), Ankle/hind foot 311 (46.3%), Multiple/whole foot 9 (1.3%). Individual MOXFQ items were assessed in terms of response rate and floor/ceiling effects, with the validity of the three MOXFQ scales (Walking/standing, Pain, and Social interaction) being assessed in terms of item-total correlations, internal and test-retest reliability, and construct validity. MOXFQ item response rates were high (all >98%). Cronbach's alphas of >0.7 confirmed internal consistency of all three scales. Test-retest ICCs were all ≥0.89. Correlations of >0.4 obtained with related SF-36 and AOFAS scales supported a priori hypotheses. Good measurement properties are confirmed for the MOXFQ in the context of baseline assessment of patients receiving surgery for a variety of foot or ankle problems.