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Table 2 Methods used to calculate minimal clinically important difference

From: Minimal clinically important difference of commonly used patient-reported outcome measures in total knee arthroplasty: review of terminologies, methods and proposed values

CitationTestMethodAnchor questionTransitional scale
Quintana et al., 2006 [16]WOMAC and SF-36Mean changeNot specified5-point scale
Escobar et al., 2007 [14]WOMAC and SF-36Mean changeNot specified5-point scale
Chesworth et al., 2008 [13]WOMAC*ROC“Compared to when they went on the wait list for surgery, they were better, worse or the same”15-point scale
Escobar et al., 2013 [17]WOMAC*Mean change
“Compared to before surgery, how would you rate pain (functional limitation) in the same knee?”
“Was surgery worthwhile?”
“What is your global level of satisfaction with surgical management?”
5-point scale
Clement et al., 2014 [18]OKS and SF-12 PCSLinear regression analysis“How well did the surgery relieve pain in your affected joint?”
“How well did the surgery increase your ability to perform regular activities?”
5-point scale
Escobar et al., 2014 [15]WOMAC*Mean changeNot specified5-point scale
Maratt et al., 2015 [12]WOMAC*ROC“How much did your knee surgery improve the quality of your life?6-point scale
Beard et al., 2015 [28]OKSMean difference
Mean change and ROC
“Overall, how are your problems now, compared to before your operation?”5-point scale
Lee et al., 2017 [21]KSSLinear regression analysisHow would you rate the overall results of the surgery for your knee condition?”6-point scale
Ingelsrud et al., 2018 [29]OKSMean change
Logistic regression and ROC
“How are your knee problems now compared to prior to operation?”7-point scale
Lizaur-Utrilla et al., 2019 [23]KSSMean difference
ROC and 0.5 SD
“Compared to before surgery, how would you rate the pain in your knee and the ability to perform regular activities now?5-point scale
Clement et al., 2019 [25]SF-12Mean difference
“How much did the knee replacement surgery improve the quality of your life?”5-point scale
Kiran et al., 2014 [19]OKS0.5 SDDistribution-based method
Keurentjes et al. 2014 [26]SF-360.8 SDDistribution-based method
Kiran, et al., 2015 [27]OKS0.5 SDDistribution-based method
Bin Abd Razak et al., 2016 [20]OKS and SF-36 PCS0.5 SDDistribution-based method
Berliner, et al., 2017 [22]SF-12 PCS0.5 SDDistribution-based method
Blevins et al., 2019 [24]SF-120.5 SDDistribution-based method
  1. MCID minimal clinically important difference, TKA total knee arthroplasty, PROM patient-reported outcome measures, WOMAC Western Ontario And McMaster University Arthritis Index, WOMAC* Western Ontario and McMaster University Arthritis Index reversed scoring system, OKS Oxford Knee Score, KSS Knee Society Score, SF-36 36-item Short Form survey, PCS physical component summary, SF-12 12-item Short Form Survey, ROC receiver operator characteristics, 0.5 SD half of a standard deviation, , 0.8 SD four fifths of a standard deviation