Confiabilidad de la sensibilidad y especificidad del 100 porciento / Trust in sensibility-specificity of 100 percent

RESUMO

A new strategy and 4 methods are presented to calculate the limits of the confident interval for an estimate of a proportion equalto 1.0 or 0.0. A current formula which includes 1/(2n) for continuity correction leads to a confident interval which does not include the parameter estimate. Thus, it is proposed 1) The exclusion of the factor 1/(2n) in that formula leads to correct most of its inconsistences. The new strategy assumes that the upper limit of a confident interval when the estimates is 100 percent is also 100 percent. The lower limit is calculated by assuming that there is a proportion in the population, from where the sample was taken, such as the probability of getting 100 percent in the sample is equal to the probability of falling into type 1 error of current statistics (0.05, 0.01, etc.). Three methods are proposed with this strategy. 2) A combinatorial solution based in the knowledge of the number of individuals at whom the test can be applied. 3) A solution based on the binomial distribution. 4) A solution based on the Poisson distribution