The screening calculator is designed to assist in estimating the number of true and false positives as well as true and false negatives that are likely to result in a screening program based on the sensitivity (SE) and specificity (SP) of the screening instrument(s) and the base rate (prevalence) of the disorder in the sample of interest.
Section 1 can be used to estimate the results of screening for a single screening instrument or for the first step in sequential screening. An estimate of the sample size, base rate, SE and SP values is needed.
Section 2 can be used to estimate the results of sequential screening. Information from section 1 is automatically transferred to Section 2, but the SE and SP for the second screening measure must be entered.