Table 8. Predictive value of Randot Preschool in detecting binocular vision problems, by age-group, taking “pass” as a score of 800 arcsec or lower.

N = number of children, TP = number of true positives (those who had a binocular vision problem and failed the stereotest), FP = number of false positives, TN = number of true negatives, FN = number of false negatives, PPV = positive predictive value, NPV = negative predictive value (see Fig 9).

	N	TP	FP	TN	FN	Sensitivity	Specificity	PPV	NPV
2 & 3yo	203	1	17	179	6	14	91	6	97
4 & 5yo	207	3	5	197	2	60	98	38	99
6 & 7yo	266	4	2	251	9	31	99	67	97
9, 10 & 11yo	216	5	2	195	14	26	99	71	93
All	892	13	26	822	31	30	97	33	96