Table 3.

Proposed minimal clinical important difference (MCID) values after total knee arthroplasty

Test	Citation	Follow-up	Subset	Method	Value	Variability (if reported)	Measurement error (if reported)
WOMAC	Quintana et al., 2006 [16]	6 months	Pain	Mean change	22.6		22.9
			Function		17.7		12.7
			Stiffness		12.9		29.1
	Escobar et al., 2007 [14]	2 years	Overall	Mean change	15.0
			Pain		27.9		22.4
			Function		20.8		13.1
			Stiffness		21.4		29.1
	Chesworth et al., 2008 [13]	1 year	Pain	ROC	36.0
			Function		33.0
	Escobar et al., 2013 [17]	1 year	Pain	Global	30.0		8.6
				Mean change	29.9	27.1 to 32.6
				ROC	20.5	20.2 to 20.9
				Additional anchors	27.0
			Function	Global	32.0		5.1
				Mean change	31.1	28.3 to 33.9
				ROC	24.2	23.6 to 24.7
				Additional anchors	20.0
	Escobar et al., 2014 [15]	1 year	Pain	Mean change	29.0	27.0 to 31.1
			Function		32.4	30.5 to 34.2
	Maratt et al., 2015 [12]	2 years	Pain	ROC	31.3
			Function		26.9
			Stiffness		25.0
OKS	Clement et al., 2014 [18]	1 year	Pain	Regression analysis	5.0	4.4 to 5.5
			Function		4.3	3.8 to 4.8
	Kiran et al., 2014 [19]	6 months	Overall	0.5 SD	4.9
	Kiran et al., 2015 [27]	2 years	Overall	0.5 SD	4.7 at 1 year and 5.0 at 2 years
	Beard et al., 2015 [28]	6 months	Overall	Mean change	9.0		4.0
				Mean difference	5.0
				ROC	7.0
	Bin Abd Razak et al., 2016 [20]	5 years	Overall	0.5 SD	5.0
OKS	Ingelsrud et al., 2018 [29]	1 year	Overall	Mean change	10.0	8.0 to 11.0
				ROC	9.0	6.0 to 15.0
				Regression analysis	8.0	6.0 to 9.0
KSS	Lee et al., 2017 [21]	2 years	Knee score	Regression analysis	5.9	3.9 to 7.8
			Function score		6.4	4.4 to 8.4
	Lizaur-Utrilla et al., 2019 [23]	2 years	Knee score	Mean difference	7.2	5.1 to 7.8
				ROC	8.9
				0.5 SD	7.2	5.3 to 9.0
			Function score	Mean difference	9.7	7.3 to 10.2
				ROC	10.3
				0.5 SD	6.3	5.0 to 8.1
SF-36	Quintana et al., 2006 [16]	6 months	Physical functioning	Mean change	10.4		20.2
			Role physical		7.8		28.7
			Bodily pain		12.8		42.3
			General health		0.1		27.0
			Vitality		5.4		29.7
			Social functioning		8.8		42.1
			Role emotional		2.4		28.1
			Mental health		0.8		23.9
	Escobar et al., 2007 [14]	2 years	Global	Mean change	10.0
			Physical functioning		11.1	5.8 to 16.3	19.5
			Role physical		13.2	3.5 to 22.8	26.9
			Bodily pain		6.7	− 0.4 to 13.8	37.9
			General health		− 7.3	− 11.3 to − 3.3	27.4
			Vitality		3.4	− 2.2 to 9.1	41.2
			Social functioning		6.2	− 1.7 to 14.0	28.5
			Role emotional		2.4	− 9.2 to 14.1	29.8
			Mental health		4.0	− 1.7 to 9.7	24.2
	Keurentjes et al., 2014 [26]	1.5 to 6 years	Physical functioning	0.8 SD	16.7	15.5 to 18
			Role physical		33.4	31.2 to 36
			Bodily pain		16.2	15.1 to 17.5
			General health		15.7	14.7 to 16.9
			Vitality		16.7	15.6 to 18.0
			Social functioning		19.9	18.6 to 21.5
			Role emotional		33.3	31.3 to 36.2
			Mental health		14.1	13.2 to 15.2
	Bin Abd Razak et al., 2016 [20]	5 years	PCS	0.5 SD	10.0
SF-12	Clement et al., 2014 [18]	1 year	PCS	Regression analysis	4.5 (Pain relief)	3.9 to 5.2
					4.8 (Function)	4.2 to 5.4
	Berliner, et al., 2017 [22]	1 year	PCS	0.5 SD	5.0
	Blevins et al., 2019 [24]	2 years	PCS	0.5 SD	5.0
			MCS		5.4
	Clement et al., 2019 [25]	1 year	PCS	Mean difference	1.8
				ROC	2.7
			MCS	Mean difference	1.5
				ROC	−1.4
	Clement et al., 2014 [18]	1 year	PCS	Regression analysis	4.5 (Pain relief)	3.9 to 5.2
	Berliner, et al., 2017 [22]				4.8 (Function)	4.2 to 5.4
		1 year	PCS	0.5 SD	5.0
	Blevins et al., 2019 [24]	2 years	PCS	0.5 SD	5.0
			MCS		5.4
	Clement et al., 2014 [18]	1 year	PCS	Regression analysis	4.5 (Pain relief)	3.9 to 5.2
	Berliner, et al., 2017 [22]	1 year	PCS	0.5 SD	4.8 (Function)	4.2 to 5.4

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, 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