Table 2. Detailed performance characteristics of patient profiles for the top five candidate definition presented at the consensus conference.

								PRINTO trial*			RIM trial†
Improve- ment category	Candidate definition for response criteria	Candidate definition type based on final consensus rank order	Core set measures	Sensitivity (%)	Specificity (%)	Threshold AUC‡	Total Improvement Score AUC§	Tx (%)	Ctrl (%)	P value	Response criteria, improved‖	Response criteria, not improved‖	P value	Rank
Minimal	Improvement Score ≥ 30	Conjoint analysis, absolute percent change Model 3 (Table 3)¶	IMACS	89	91	0.90	0.98	75	53	0.009	2.0	3.0	<0.001	1
			PRINTO	89	98	0.93	0.99	73	55	0.038
Moderate	Improvement Score ≥ 45		IMACS	92	99	0.95	0.99	70	53	0.057	2.0	3.0	<0.001
			PRINTO	94	94	0.94	0.99	71	51	0.023
Major	Improvement Score ≥ 70		IMACS	91	86	0.89	0.96	51	43	0.341	2.0	3.0	0.006
			PRINTO	98	85	0.91	0.98	58	49	0.331
Minimal	Improvement Score ≥ 33	Conjoint analysis, relative percent change# Model 1 (Supplementary Table 3)	IMACS	99	87	0.93	0.98	75	55	0.018	2.0	4.0	<0.001	2
			PRINTO	96	98	0.97	1.00	74	55	0.027
Moderate	Improvement Score ≥ 60		IMACS	97	93	0.95	0.99	73	51	0.011	2.0	3.0	<0.001
			PRINTO	97	96	0.96	1.00	70	51	0.032
Major	Improvement Score ≥ 80		IMACS	91	87	0.89	0.96	57	49	0.396	1.5	3.0	<0.001
			PRINTO	98	86	0.92	0.97	61	49	0.179
Minimal	Improvement Score ≥ 33	Conjoint analysis, relative percent change# Model 2 (Supplementary Table 3)	IMACS	95	94	0.94	0.98	75	53	0.009	2.0	4.0	<0.001	3
			PRINTO	94	98	0.96	0.99	74	55	0.027
Moderate	Improvement Score ≥ 55		IMACS	95	95	0.95	1.00	70	51	0.032	2.0	3.0	<0.001
			PRINTO	97	98	0.98	1.00	70	51	0.032
Major	Improvement Score ≥ 77		IMACS	93	86	0.90	0.97	49	47	0.814	1.0	2.0	0.011
			PRINTO	96	90	0.93	0.99	59	49	0.273
Minimal	Improvement Points given when CS≥20; Worsening Points given when CSM worse by > 30	Weighted definition, relative percent change**	IMACS	95	100	0.97	NA	70	51	0.032	2.0	3.0	<0.001	4
								73	53	0.021
			PRINTO	92	98	0.95	NA
Moderate	Improvement Points given when CSM ≥ 50%; Worsening Points given when CSM worse by >30%		IMACS	95	91	0.93	NA	68	51	0.045	2.0	3.0	<0.001
								71	51	0.023
			PRINTO	95	92	0.94	NA
Major	Improvement Points given when CSM≥75%; Worsening Points given when CSM worse by >30%		IMACS	100	81	0.91	NA	64	47	0.050	1.5	3.0	<0.001		5
								62	49	0.142
			PRINTO	98	85	0.91	NA
Minimal	3 of any 6improved by ≥20%; no more than 1 worse by > 30%; which cannot be MMT/CMAS (8)	Previously published definition (8;9), relative percent change	IMACS	93	100	0.97	NA	70	51	0.032	2.0	3.0	<0.001
								71	51	0.023
			PRINTO	88	100	0.94	NA
Moderate	3 of any 6 improved by ≥ 50%; no more than 1 worse by > 30%; which cannot be MMT/CMAS (9)		IMACS	90	95	0.93	NA	66	51	0.081	2.0	3.0	<0.001
								68	51	0.045
			PRINTO	90	96	0.93	NA
Major	3 of any 6 improved by ≥ 70%; no more than 1 worse by > 30%; which cannot be MMT/CMAS (9)		IMACS	99	83	0.91	NA	63	49	0.111	2.0	3.0	<0.001
								60	49	0.223
			PRINTO	99	89	0.94	NA

The performance characteristics of patient profiles for definitions ranked 6-14 are presented in Supplementary Table 1.

Abbreviations: AUC, area under the curve; Minimal, minimal improvement; Moderate, moderate improvement; Major, major improvement; IMACS, International Myositis Assessment and Clinical Studies Group; PRINTO, Paediatric Rheumatology International Trials Organization; CSM, core set measure; NA, not applicable; MMT, manual muscle testing; CMAS, Childhood Myositis Assessment Scale.

Note that either IMACS or PRINTO CSM may be used in these candidate definitions of response; the candidate definitions were developed in parallel with IMACS or PRINTO CSM.

^*PRINTO juvenile dermatomyositis trial of prednisone alone versus prednisone with methotrexate or cyclosporine (n = 139) (11).

^†Rituximab in Myositis (RIM) Trial, juvenile dermatomyositis arm (n =48). Comparison of the treating physician's rating of improvement if the improvement criteria are met versus not at week 24 (19). A 1-point difference in physician rating of improvement from no improvement to minimal improvement was considered not just statistically significant, but also was clinically significant.

^‡Threshold AUC, area under the curve, calculated as the AUC from the receiver operating characteristic curve for the Total Improvement Score and the threshold for minimal, moderate, and major improvement.

^§Total Improvement Score AUC, calculated as the AUC from the receiver operator characteristic curve, using the Total Improvement Score and the threshold cutoffs for minimal, moderate, and major improvement, which applies only to continuous definitions.

Median Physician Improvement Score.

^¶Conjoint analysis–based continuous candidate response criteria using absolute percent change in core set measures (absolute percent change model) is presented in Table 3. These criteria are also the top response criteria for adult dermatomyositis/polymyositis, but with different thresholds in the Total Improvement Score for minimal, moderate, and major improvement (22).

^#Conjoint analysis–based continuous candidate definitions using relative percent change in core set measures are presented in Supplementary Table 3. These criteria are also the second and third choice criteria for adult dermatomyositis/polymyositis, but with different thresholds in the Total Improvement Score for minimal, moderate, and major improvement (22).

^**Improvement = at least 3.5 Improvement Points out of 10 Total Improvement Points, and no more than 1.5 Worsening Points, where Physician Global Activity = 2 points; Parent Global Activity = 1 point; MMT or CMAS = 3 points; CHAQ = 1.5 points, Extramuscular Global Activity or Disease Activity Score = 1.5 points, Enzyme or Physical Summary Score of the Child Health Questionnaire-Parent Form 50 = 1 point.