Responsiveness and minimally important change for the Manchester-Oxford foot questionnaire (MOXFQ) compared with AOFAS and SF-36 assessments following surgery for hallux valgus

Osteoarthritis Cartilage. 2007 Aug;15(8):918-31. doi: 10.1016/j.joca.2007.02.003. Epub 2007 Mar 26.


Objectives: To assess responsiveness and minimally important change (MIC) for the Manchester-Oxford foot questionnaire (MOXFQ) using anchor and distribution-based approaches. Responsiveness and estimates of minimal clinically important difference (MCID) and minimal detectable change are compared with those from the Short-Form 36 (SF-36) and American Orthopaedic Foot & Ankle Society (AOFAS) measures.

Methods: A prospective observational study of 91 consecutive patients (125 foot operations) undergoing hallux valgus surgery at an orthopaedic hospital. Pre- and 12 month post-surgery, patients completed the MOXFQ and SF-36, and foot surgeons assessed all four AOFAS scores corresponding to four regions of the foot. Transition items were asked about perceived changes compared with before surgery.

Results: Mean changes in all domains of each instrument were statistically significant, but foot-specific MOXFQ and AOFAS domains produced much larger effect sizes (>1) than any SF-36 domains, indicating superior responsiveness. Clear associations occurred between transition items and all MOXFQ and AOFAS scores, but with only one (physical function) SF-36 domain. Anchor and distribution-based approaches identified generally comparable measures of MIC, which for the MOXFQ and AOFAS domains were between 1 and 2 standard error of measurement. In metric terms, the MCIDs were 16, 12, and 24 for the MOXFQ Walking/standing, Pain, and Social Interaction domains, respectively.

Conclusions: For hallux valgus surgery, the MOXFQ is highly responsive. Performance is comparable to the AOFAS and notably better than the generic SF-36. Study estimates of MIC for the MOXFQ are useful to inform sample-size calculations for future clinical trials.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Activities of Daily Living
  • Adult
  • Aged
  • Hallux Valgus / psychology*
  • Hallux Valgus / surgery*
  • Humans
  • Middle Aged
  • Motor Activity
  • Pain, Postoperative / psychology
  • Prospective Studies
  • Quality of Life*
  • ROC Curve
  • Reproducibility of Results
  • Surveys and Questionnaires / standards*