Table 3. Diagnostic accuracy of candidate questions in the draft version of questionnaire (preliminary study conducted in hospital and community settings).

	Hospital-based survey (n=1,756)						Community-based survey (n=1,320)
	Sensitivity (%)	Specificity (%)	PPV (%)	NPV (%)	ER (%)	Youden's index (%)	Sensitivity (%)	Specificity (%)	PPV (%)	NPV (%)	ER (%)	Youden's index (%)
Candidate Questions for Major Criteria
Recurrent skin rash during last year	99.6	78.5	93.8	98.2	5.4	78.1	94.6	83.0	41.5	99.2	15.7	77.6
Itchy rash on the antecubital/popliteal fossae	78.4	94.2	97.8	57.4	17.9	72.6	91.9	91.5	57.8	98.9	8.5	83.4
Itchy rash around the neck	53.8	75.8	89.2	38.0	36.5	29.6	26.8	97.1	54.1	91.3	10.8	23.9
Itchy rash on the infragluteal folds	39.5	88.2	90.7	29.7	47.2	27.7	14.8	98.2	51.2	90.1	11.2	13.0
Itchy rash on the wrist/ankle joints	22.1	93.2	91.4	27.0	55.4	15.3	10.1	99.3	65.2	89.7	10.8	9.4
Personal or family history of atopy	76.5	39.4	80.4	34.1	32.2	15.9	79.9	49.4	16.7	95.1	47.1	29.3
Candidate Questions for Minor Criteria
Localized eczema
Eye eczema	48.8	78.7	88.2	32.2	44.1	27.5	26.8	91.4	28.4	90.8	15.9	18.2
Ear eczema	48.8	86.7	92.3	34.3	42.3	35.5	20.1	97.4	50.0	90.6	15.9	17.5
Lip eczema	39.3	82.9	88.1	29.6	50.5	22.2	24.2	94.2	34.6	90.7	13.7	18.4
Hand/foot eczema	34.9	80.0	85.0	27.5	61.2	14.9	9.5	96.5	32.1	86.0	16.3	6.0
Nipple eczema	20.6	93.0	90.5	26.6	62.3	13.6	6.7	99.1	50.0	89.3	11.3	5.8
Environmental factor
Unusually dry skin	88.3	44.0	83.6	53.7	22.2	32.3	67.1	79.9	29.9	95.0	21.5	47.0
Itch by sweating	79.4	57.2	85.7	46.1	25.9	36.6	70.5	81.6	32.8	95.6	19.6	52.1
Aggravation by wools	52.0	79.5	89.1	33.8	41.5	31.5	19.1	96.2	46.3	87.3	15.2	15.3
Aggravation by soaps	37.0	84.5	88.6	29.3	51.8	21.5	9.9	97.5	40.6	86.2	15.4	7.4
Aggravation by foods	46.1	77.3	86.8	30.7	46.6	23.4	19.5	93.2	38.0	87.7	17.0	12.7

PPV, positive predictive value; NPV, negative predictive value; ER, error rate.