Comparison of some methods for determining cutoff values for serological assays: A retrospective study using the fluorescence polarization assay

Different methods for determining cutoff values between positive and negative results for serological assays have been developed over time. Comparisons of some these methods show that five (Receiver Operating Characteristics, Frequency Distribution, and the mean, median and mode of the 100th percentile of a disease-free group of data) resulted in similar sensitivity (99.11%) and specificity values (99.21% to 99.58%). However, the Receiver Operating Characteristic analysis was considered more suitable, due to the ease of data manipulation and computer analysis, providing flexibility for different field applications.