Development and validation of the Pictorial Cognitive Screening Inventory for illiterate people with dementia

Figures & data

Table 1 Demographic variables for each group

	Normal		Dementia		P-value	Total (n=80)
	Illiterate (n=20)	Literate (n=20)	Illiterate (n=20)	Literate (n=20)
Age (SD)	71.75 (4.27)	70.60 (4.43)	82.35 (4.17)	73.70 (6.09)	0.000	74.60 (6.61)
Education (SD)	0.55 (1.50)	6.45 (3.94)	0.30 (0.80)	8.45 (5.36)	0.000	3.94 (4.93)
Sex (M:F)	0:20	2:18	1:19	10:10	0.000	13:67

Abbreviations: F, female; M, male; SD, standard deviation.

Table 2 Means and standard deviations for the PCSI and the MMSE scores by dementia status and literacy status

	Normal			Dementia
	Illiterate (n=20)	Literate (n=20)	P-value	Illiterate (n=20)	Literate (n=20)	P-value
PCSI
Delayed recall	4.10 (0.97)	4.75 (1.16)	0.063	1.40 (1.31)	0.90 (1.12)	0.203
Delayed recognition	8.90 (1.25)	8.70 (1.63)	0.665	4.85 (3.83)	3.45 (4.01)	0.266
Selective attention	48.55 (2.59)	49.20 (1.24)	0.317	45.05 (8.10)	44.70 (5.16)	0.871
MMSE	21.70 (2.89)	25.25 (2.86)	0.000	15.00 (4.35)	19.05 (3.72)	0.003

Note: Data are presented as mean (SD) unless otherwise indicated.

Abbreviations: MMSE, Mini Mental State Examination; PCSI, Pictorial Cognitive Screening Inventory; SD, standard deviation.

Table 3 Cut-off points, sensitivity, specificity, and correct classification rate for PCSI subtest scores and MMSE score

	Group	ROC area	Cut-off	True positive (sensitivity)	True negative (specificity)	False negative (FNR)	False positive (FPR)	CCR
Delayed recall	Illiterate	0.94	<3	17 (0.85)	20 (1.00)	3 (0.15)	0 (0.00)	0.93
	Literate	0.98	<3	19 (0.95)	19 (0.95)	1 (0.05)	1 (0.05)	0.95
	Total	0.97	<3	36 (0.90)	39 (0.98)	4 (0.10)	1 (0.02)	0.94
Delayed recognition	Illiterate	0.84	<7	11 (0.55)	19 (0.95)	9 (0.45)	1 (0.05)	0.75
	Literate	0.85	<7	14 (0.70)	19 (0.95)	6 (0.30)	1 (0.05)	0.83
	Total	0.85	<7	25 (0.63)	38 (0.95)	15 (0.37)	2 (0.05)	0.79
Selective attention	Illiterate	0.67	<49	12 (0.60)	15 (0.75)	8 (0.40)	5 (0.25)	0.68
	Literate	0.85	<49	15 (0.75)	17 (0.85)	5 (0.25)	3 (0.15)	0.80
	Total	0.76	<49	27 (0.68)	32 (0.80)	13 (0.32)	8 (0.20)	0.74
MMSE	Illiterate	0.90	<23	19 (0.95)	8 (0.40)	1 (0.05)	12 (0.60)	0.68
	Literate	0.90	<23	15 (0.75)	16 (0.80)	5 (0.25)	4 (0.20)	0.78
	Total	0.87	<23	34 (0.85)	24 (0.60)	6 (0.15)	16 (0.40)	0.73

Note: <: classified into dementia group if smaller than the given figure.

Abbreviations: CCR, correct classification rate; MMSE, Mini Mental State Examination; ROC, receiver operating characteristic; PCSI, Pictorial Cognitive Screening Inventory; SD, standard deviation; FNR, false-negative rate; FPR, false-positive rate.

Figure 1 Receiver operating characteristic curve analysis of the PCSI and MMSE scores for detecting dementia.

Abbreviations: MMSE, Mini Mental State Examination; PCSI, Pictorial Cognitive Screening Inventory.

Table 4 Cut-off points, sensitivity, specificity, and correct classification rate for PCSI composite score and MMSE score

Group	ROC area	Cut-off	True positive (sensitivity)	True negative (specificity)	False negative (FPR)	False positive (FPR)	CCR
PCSI
Illiterate	0.95	<−0.04	17 (0.85)	20 (1.0)	3 (0.15)	0 (0.00)	0.93
Literate	0.99	<−0.04	36 (0.90)	38 (0.95)	4 (0.10)	2 (0.05)	0.93
Total	0.98	<−0.04	36 (0.90)	39 (0.98)	4 (0.10)	1 (0.02)	0.94
MMSE
Illiterate	0.90	<23	19 (0.95)	8 (0.40)	1 (0.05)	12 (0.60)	0.68
Literate	0.90	<23	15 (0.75)	16 (0.80)	5 (0.25)	4 (0.20)	0.78
Total	0.87	<23	34 (0.85)	24 (0.60)	6 (0.15)	16 (0.40)	0.73

Note: <: classified into dementia group if smaller than the given figure.

Abbreviations: CCR, correct classification rate; MMSE, Mini Mental State Examination; PCSI, Pictorial Cognitive Screening Inventory; ROC, receiver operating characteristic; FNR, false-negative rate; FPR, false-positive rate.

Figure S1 Examples of pictorial stimuli in the pictorial memory test: flower (left) and umbrella (right).