Summary of results from this and previous studies.

The study is identified in the “Reference” column; “.” indicates this study (values in red). Numbers of children for our study refer to testability and are smaller for other columns; see relevant sections for details. Values in italics were inferred from the data provided in the paper, e.g. by reading off values from figures and/or using the formulae in Table 2. Note that Yang et al[15] claim to provide sensitivity and specificity for the Randot Preschool, but this appears to be incorrect. First, their sample is described as “100 normal children without ocular disease” and specifically excluded children with strabismus or amblyopia, so it is not clear who the “true positives” would be. Second, the denominators used in the calculation of sensitivity and specificity are the number of children in each age-group, not the number of children passing/failing the test. Third, the sensitivity values are over 90% in all age-groups, far higher than any other report. Thus, we have excluded their data.