Maximally efficient two-stage screening: Determining intellectual disability in Taiwanese military conscripts

Figures & data

Figure 1A Two-stage positive screening.

Note: Black box indicates the group of participants referred for further intervention.

Figure 1B Two-stage negative screening.

Note: Black boxes indicate groups of participants referred for further intervention.

Figure 2 Two-stage window screening.

Note: Participants whose scores were in the thickened area have to be tested in the second stage.

Table 1 The distribution of the WAIS-R and WCST scores, and the correlation among each subtest

Correlation	Range	M (SD)	FIQ	CA	PPE	TCFC	CLR	FMS	LL
FIQ	47–122	88.57 (13.67)		0.454**	−0.469**	−0.209**	0.551**	−0.079**	0.273**
CA	0–6	4.48 (1.88)			−0.696**	−0.547**	0.904**	−0.084	0.218**
PPE	5.71–57.03	15.48 (8.29)				0.439**	−0.737**	−0.070	−0.325**
TCFC	10–102	24 (20.88)					−0.584**	−0.021	0.435**
CLR	3.13–91.89	56.74 (20.75)						0.088	0.162
FMS	0–5	1.19 (1.18)							−0.046
LL	−28.28–16.30	0.62 (6.90)

Notes:

* p < 0.05;

** p < 0.001.

Abbreviations: CA, categories achieved; CLR, conceptual-level responses; FIQ, WAIS-R Full IQ; FMS, failure to maintain the set; LL, learning to learn; PPE, percent preservative errors; SD, standard deviation; TCFC, trials to complete the first category; WAIS-R, Wechsler Adult Intelligence Scale-Revised; WCST, Wisconsin Card Sorting Test.

Table 2 Results of multiple logistic regression analysis of the indexes of the WCST and ID

The WCST index	β	Standard error	pvalue
CLR	−0.047	0.012	0.000**
Constant	2.123	0.709	0.003**

Notes:

* p < 0.05;

** p < 0.001

Abbreviations: CLR, conceptual level responses; ID, intellectual disability; WCST, Wisconsin Card Sorting Test.

Table 3 Results of using one cut-off and two cut-off points in each group showing intellectual status (Unit: person)

		Total (%)
One cut-off point	CLR > 66	38 (38.4%)
	CLR ≤ 66	61 (61.6%)
Two cut-off points	CLR > 66	38 (38.4%)
	CLR = 49–66	25 (25.3%)
	CLR < 49	36 (36.4%)

Abbreviation: CLR, conceptual level responses.

Table 4 Comparison of results using two-stage positive screening and two-stage window screening

	Two-stage positive screening using the one cutoff point of CLR = 66	Two-stage window screening using the two cutoff points of CLR = 66 and CLR = 49
ROC area (AUC)	0.71	0.82
Sensitivity	0.87	0.87
Specificity	0.54	0.77
PPV	0.54	0.70
NPV	0.87	0.90
Total cost of WAIS-R (USD)	1311.50 (100%)	537.50 (41%)

Abbreviations: AUC, area under the curve; NPV, negative predictive value; ROC, receiver operating characteristic; PPV, positive predictive value; WAIS-R, Wechsler Adult Intelligence Scale-Revised.