Table 5.

Prediction of the diagnosis of Alzheimer’s disease in an out-patient population referred for evaluation of dementia (blinded study)

	Alzheimers disease
	P a	ORb	95-CI	P c	ORc	95-CI	PPV (%)f	NPV (%)g
Number of smell errors
1+ (0 reference)	0.045	nad			nad		52	100
2+ (0–1 reference)	0.011	12.2	1.4–105	0.026	11.6	1.3–101	58	90
3+ (0–2 reference)	0.059	3.3	0.9–11.4	0.078	3.3	0.9–12.1	58	71
4+ (0–3 reference)	0.093	2.7	0.8–8.8	0.055	3.5	1.0–12.6	63	61
5+ (0–4 reference)	0.62	1.4	0.3–6.2	0.73	1.3	0.3–6.6	56	54
6 (0–5 reference)	0.10	nae			nae		100	55

^aChi squared test, Fisher’s exact test if n < 5

^bUnivariate logistic regression

^cMultivariate model adjusted for age (<80y) and MMSE (<20)

^dNot applicable: 4, all non-AD

^eNot applicable: 3 reference, all AD

^fPositive predictive value, %

^gNegative predictive value, %