Table 2.

Risk assessment

	Actual results
Test prediction	Develops psychosis	Does not develop psychosis	Total
At risk for psychosis	14	294	308
Not at risk for psychosis	6	686	692
Total	20	980	1000

Assuming that two of every 100 individuals will ultimately develop schizophrenia or a psychotic mood disorder, this means that of a group of 1000, 20 individuals will develop a psychotic disorder and 980 will not. Assuming that the sensitivity of the at-risk criteria is 70%, this means that the criteria will correctly identify 12 but miss 6 individuals truly at risk. Assuming that the specificity is 60%, the test will correctly identify 686 as not at risk, but will misclassify 294 individuals as at risk, even though they are truly not at risk.