TABLE 1.

Study 1: mean, standard deviation (in italics), and minimum/maximum score [in brackets] for the direct and informant‐based measures of cognition and functioning × diagnostic status × severity of ID for the baseline assessment

	CS (N = 424)				MCI‐DS (N = 79)				Dementia (N = 58)
Measure (maximum score)	Mild (N = 146)	Moderate (N = 121)	Severe (N = 110)	Profound (N = 44)	Mild (N = 14)	Moderate (N = 24)	Severe (N = 27)	Profound (N = 12)	Mild (N = 7)	Moderate (N = 16)	Severe (N = 23)	Profound (N = 10)
MSRT‐TR (48)	31.7,9.8 [2‐48]	23.9,12.0 [0‐44]	16.1,11.6 [0‐42]	2.4,5.9 [0‐25]	16.7,10.1 [3‐33]	13.4,7.6 [0‐30]	8.4,9.4 [0‐35]	2.2,5.3 [0‐13]	7.3,7.5 [0‐17]	9.6,9.3 [0‐27]	1.9,4.2 [0‐13]	0.3,0.5 [0‐1]
TSI‐T (24)	21.3,1.9 [16‐24]	19.9,2.6 [7‐24]	15.1,5.0 [0‐23]	6.5,4.6 [0‐17]	19.4,2.2 [16‐22]	16.6,5.1 [2‐22]	13.5,5.4 [2‐23]	5.3,5.8 [0‐14]	16.0,2.6 [13‐19]	12.4,7.8 [0‐22]	6.2,5.6 [0‐16]	3.8,4.5 [0‐10]
MMMSE‐DS‐T (74)	65.0,7.5 [29‐74]	53.7,13.2 [4‐73]	32.2,19.9 [0‐66]	4.1,8.8 [0‐37]	54.2,10.2 [14‐32]	37.7,17.9 [0‐30]	24.4,18.5 [0‐60]	3.7,8.3 [0‐22]	19.2,23.3 [0‐56]	26.1,25.4 [0‐61]	6.6,11.8 [0‐40]	0.5,1.6 [0‐5]
DSMSE‐M (24) DSMSE‐NM (79)	15.0,4.9 [0‐24] 58.6,10.3 [31‐78]	12.4,4.5 [0‐22] 48.3,11.6 [7‐68]	8.2,5.5 [0‐22] 34.3,13.4 [0‐69]	1.3,2.6 [0‐11] 14.1,11.8 [0‐37.5]	7.6,4.6 [1‐16] 48.1,9.4 [28‐65.5]	5.3,4.0 [0‐17] 34.5,14.2 [8‐56]	4.2,4.3 [0‐17] 25.8,13.8 [5‐58]	0.8,2.5 [0‐8] 11.3,14.0 [0‐33]	1.8,2.5 [0‐5] 28.1,8.5 [19‐39]	2.12,3.0 [0‐11] 29.5,21.1 [0‐62]	0.6,1.4 [0‐6] 13.3,13.1 [0‐41]	0.2,0.6 [0‐2] 7.8,10.4 [0‐22]
CF‐Ta	8.5,3.2 [1‐17]	3.8,6.3 [0‐14]	3.4,3.0 [0‐14]	.56,1.3 [0‐4]	5.7,2.8 [1‐10]	3.7,3.2 [0‐11]	2.0,3.0 [0‐12]	.71,1.3 [0‐3]	2.3,2.6 [0‐5]	2.3,2.6 [0‐7]	0.6,1.2 [0‐4]	0.0
VMI‐T (27)	12.8,3.5 [0‐23]	10.4,2.9 [0‐18]	7.0,3.8 [0‐16]	1.2,1.9 [0‐7]	10.8,1.2 [8‐13]	7.2,3.6 [0‐12]	4.5,3.8 [0‐12]	.50,1.2 [0‐3]	4.8,4.3 [2‐11]	5.6,4.7 [0‐13]	2.3,3.4 [0‐9]	0.3,0.5 [0‐1]
BLOCK‐T (78)	19.8,9.4 [0‐53]	12.7,7.6 [0‐34]	6.0,6.1 [0‐26]	0.1,0.4 [0‐2]	11.9,8.8 [0‐26]	4.9,4.7 [0‐14]	3.5,4.6 [0‐13]	0.0	1.5,1.9 [0‐4]	4.5,5.5 [0‐13]	0.8,1.8 [0‐6]	0.0
DLD‐SCSb (50) DLD‐SOSb (52)	3.6,4.4 [0‐21] 6.4,5.2 [0‐24]	8.3,7.2 [0‐36] 7.5,5.5 [0‐29]	14.3,8.9 [0‐35] 9.3,6.0 [0‐25]	29.0,9.1 [0‐44] 19.6,8.5 [5‐38]	10.9,7.3 [1‐24] 10.0,5.4 [3‐25]	18.6,8.9 [3‐36] 12.2,6.0 [4‐26]	23.1,8.0 [6‐40] 14.6,6.2 [3‐32]	33.4,8.3 [15‐44] 25.6,11.3 [10‐42]	24.3,16.6 [0‐44] 22.5,15.6 [8‐42]	28.9,10.8 [8‐44] 22.8,11.9 [9‐40]	35.7,8.1 [17‐44] 27.9,12.2 [9‐46]	37.8,5.5 [26‐44] 36.2,5.6 [27‐45]
ABSI‐T (280)	224.8,24.7 [141‐271]	204.8,26.1 [129‐260]	183.8,32.6 [66‐245]	107.3,38.1 [25‐196]	204.9,24.6 [154‐246]	177.8,33.1 [97‐228]	151.5,29.6 [92‐209]	83.6,50.0 [18‐178]	99.9,70.5 [18‐204]	127.8,64.9 [20‐209]	90.5,51.5 [19‐191]	50.2,34.6 [5‐109]

Abbreviations: ABSI‐T, American Association on Mental Deficiency Adaptive Behavior Scale, Part I‐Total Score; BLOCK‐T, Block Design Subtest‐Total Score; CF‐T, Category Fluency Test‐Total Score; CS, cognitively stable; DLD‐SCS, The Dementia Questionnaire for People with Learning Disabilities, Sum of Cognitive Scores; DLD‐SOS, The Dementia Questionnaire for People with Learning Disabilities, Sum of Social Scores; DLD‐T, The Dementia Questionnaire for People with Learning Disabilities, Total Score; DSMSE‐M, Down Syndrome Mental Status Examination‐Memory Score; DSMSE‐NM, Down Syndrome Mental Status Examination‐ Nonmemory Score; MCI‐DS, mild cognitive impairment‐Down syndrome; MMMSE‐DS‐T, Modified Mini Mental Status Examination‐Down Syndrome‐Total Score; MSRT‐TR, Modifed Selective Reminding Test‐Total Recall Score; TSI‐T, Test for Severe Impairment‐Total Score; VMI‐T, the Beery Buktenica Developmental Test of Visual‐Motor Integration‐Total Score