PMID- 28193121
OWN - NLM
STAT- MEDLINE
DCOM- 20171113
LR  - 20171113
IS  - 1944-7876 (Electronic)
IS  - 1071-1007 (Linking)
VI  - 38
IP  - 5
DP  - 2017 May
TI  - Minimal Clinically Important Differences for American Orthopaedic Foot & Ankle 
      Society Score in Hallux Valgus Surgery.
PG  - 551-557
LID - 10.1177/1071100716688724 [doi]
AB  - BACKGROUND: The American Orthopaedic Foot & Ankle Society (AOFAS) score is one of 
      the most common and adapted outcome scales in hallux valgus surgery. However, 
      AOFAS is predominantly physician based and not patient based. Although it may be 
      straightforward to derive statistical significance, it may not equate to the true 
      subjective benefit of the patient's experience. There is a paucity of literature 
      defining MCID for AOFAS in hallux valgus surgery although it could have a great 
      impact on the accuracy of analyzing surgical outcomes. Hence, the primary aim of 
      this study was to define the Minimal Clinically Important Difference (MCID) for 
      the AOFAS score in these patients, and the secondary aim was to correlate 
      patients' demographics to the MCID. METHODS: We conducted a retrospective 
      cross-sectional study. A total of 446 patients were reviewed preoperatively and 
      followed up for 2 years. An anchor question was asked 2 years postoperation: "How 
      would you rate the overall results of your treatment for your foot and ankle 
      condition?" (excellent, very good, good, fair, poor, terrible). The MCID was 
      derived using 4 methods, 3 from an anchor-based approach and 1 from a 
      distribution-based approach. Anchor-based approaches were (1) mean difference in 
      2-year AOFAS scores of patients who answered "good" versus "fair" based on the 
      anchor question; (2) mean change of AOFAS score preoperatively and at 2-year 
      follow-up in patients who answered good; (3) receiver operating characteristic 
      (ROC) curves method, where the area under the curve (AUC) represented the 
      likelihood that the scoring system would accurately discriminate these 2 groups 
      of patients. The distribution-based approach used to calculate MCID was the 
      effect size method. There were 405 (90.8%) females and 41 (9.2%) males. Mean age 
      was 51.2 (standard deviation [SD] = 13) years, mean preoperative BMI was 24.2 (SD 
      = 4.1). RESULTS: Mean preoperative AOFAS score was 55.6 (SD = 16.8), with 
      significant improvement to 85.7 (SD = 14.4) in 2 years ( P value < .001). There 
      were no statistical differences between demographics or preoperative AOFAS scores 
      of patients with good versus fair satisfaction levels. At 2 years, patients who 
      had good satisfaction had higher AOFAS scores than fair satisfaction (83.9 vs 
      78.1, P < .001) and higher mean change (30.2 vs 22.3, P = .015). Mean change in 
      AOFAS score in patients with good satisfaction was 30.2 (SD = 19.8). Mean 
      difference in good versus fair satisfaction was 7.9. Using ROC analysis, the 
      cut-off point is 29.0, with an area under the curve (AUC) of 0.62. Effect size 
      method derived an MCID of 8.4 with a moderate effect size of 0.5. Multiple linear 
      regression demonstrated increasing age (beta = -0.129, CI = -0.245, -0.013, P = 
      .030) and higher preoperative AOFAS score (beta = -0.874, CI = -0.644, -0.081, P < 
      .001) to significantly decrease the amount of change in the AOFAS score. 
      CONCLUSION: The MCID of AOFAS score in hallux valgus surgery was 7.9 to 30.2. The 
      MCID can ensure clinical improvement from a patient's perspective and also aid in 
      interpreting results from clinical trials and other studies. LEVEL OF EVIDENCE: 
      Level III, retrospective comparative series.
FAU - Chan, Hiok Yang
AU  - Chan HY
AD  - 1 Department of Orthopaedic Surgery, Singapore General Hospital, Singapore.
FAU - Chen, Jerry Yongqiang
AU  - Chen JY
AD  - 1 Department of Orthopaedic Surgery, Singapore General Hospital, Singapore.
FAU - Zainul-Abidin, Suraya
AU  - Zainul-Abidin S
AD  - 1 Department of Orthopaedic Surgery, Singapore General Hospital, Singapore.
FAU - Ying, Hao
AU  - Ying H
AD  - 2 Health Services and Biostatistics Unit, Department of Research, Singapore 
      General Hospital, Singapore.
FAU - Koo, Kevin
AU  - Koo K
AD  - 1 Department of Orthopaedic Surgery, Singapore General Hospital, Singapore.
FAU - Rikhraj, Inderjeet Singh
AU  - Rikhraj IS
AD  - 1 Department of Orthopaedic Surgery, Singapore General Hospital, Singapore.
LA  - eng
PT  - Journal Article
DEP - 20170213
PL  - United States
TA  - Foot Ankle Int
JT  - Foot & ankle international
JID - 9433869
SB  - IM
MH  - Ankle/*physiology
MH  - Cross-Sectional Studies
MH  - Hallux Valgus/*surgery
MH  - Humans
MH  - Metatarsophalangeal Joint/physiology/*surgery
MH  - *Minimal Clinically Important Difference
MH  - Orthopedics
MH  - Pain Measurement/standards
MH  - Recovery of Function
MH  - Retrospective Studies
MH  - Surveys and Questionnaires
MH  - Treatment Outcome
MH  - United States
OTO - NOTNLM
OT  - AOFAS
OT  - MCID
OT  - ROC curve
OT  - clinical outcomes
OT  - effect size
OT  - hallux valgus
OT  - mean change
OT  - mean difference
EDAT- 2017/02/15 06:00
MHDA- 2017/11/14 06:00
CRDT- 2017/02/15 06:00
PHST- 2017/02/15 06:00 [pubmed]
PHST- 2017/11/14 06:00 [medline]
PHST- 2017/02/15 06:00 [entrez]
AID - 10.1177/1071100716688724 [doi]
PST - ppublish
SO  - Foot Ankle Int. 2017 May;38(5):551-557. doi: 10.1177/1071100716688724. Epub 2017 
      Feb 13.