Table 3.

Results of orthoptic screening (phase I) by test items and cumulated, in 1093 children for whom the gold standard was obtained and who were not treated for amblyopia or amblyogenic risk factors before screening. Inconclusive results of orthoptic screening items were excluded to compute the proportion of gold standard “positive” cases which were detected by each item, and the resulting per item sensitivity and specificity

	Inconclusive results		Positive results		Negative results
Screening item	No	%	No	%	No	%	No of conclusive results	Proportion of detected gold standard “positive” cases*	Sensitivity	Specificity
Inspection	0	0.0	2	0.2	1091	99.8	1093	1/26	3.8%	99.9%
Ocular motility/head posture	47	4.3	12	1.1	1034	94.6	1046	3/25	12.0%	99.1%
Cover testing	51	4.7	13	1.2	1029	94.1	1042	4/25	16.0%	99.1%
Visual acuity	118	10.8	63	5.8	912	83.4	975	19/22	86.4%	95.4%
Cumulated	118	10.8	79	7.2	896	82.0	975	20/22	90.9%	93.8%

*Proportion of detected cases with positive gold standard among all cases with positive gold standard in children with conclusive result for the screening item (equal to sensitivity).