Estimating cutoff values for diagnostic tests to achieve target specificity using extreme value theory.
BMC Med Res Methodol
; 24(1): 30, 2024 Feb 08.
Article
en En
| MEDLINE
| ID: mdl-38331732
ABSTRACT
BACKGROUND:
Rapidly developing tests for emerging diseases is critical for early disease monitoring. In the early stages of an epidemic, when low prevalences are expected, high specificity tests are desired to avoid numerous false positives. Selecting a cutoff to classify positive and negative test results that has the desired operating characteristics, such as specificity, is challenging for new tests because of limited validation data with known disease status. While there is ample statistical literature on estimating quantiles of a distribution, there is limited evidence on estimating extreme quantiles from limited validation data and the resulting test characteristics in the disease testing context.METHODS:
We propose using extreme value theory to select a cutoff with predetermined specificity by fitting a Pareto distribution to the upper tail of the negative controls. We compared this method to five previously proposed cutoff selection methods in a data analysis and simulation study. We analyzed COVID-19 enzyme linked immunosorbent assay antibody test results from long-term care facilities and skilled nursing staff in Colorado between May and December of 2020.RESULTS:
We found the extreme value approach had minimal bias when targeting a specificity of 0.995. Using the empirical quantile of the negative controls performed well when targeting a specificity of 0.95. The higher target specificity is preferred for overall test accuracy when prevalence is low, whereas the lower target specificity is preferred when prevalence is higher and resulted in less variable prevalence estimation.DISCUSSION:
While commonly used, the normal based methods showed considerable bias compared to the empirical and extreme value theory-based methods.CONCLUSIONS:
When determining disease testing cutoffs from small training data samples, we recommend using the extreme value based-methods when targeting a high specificity and the empirical quantile when targeting a lower specificity.Palabras clave
Texto completo:
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Base de datos:
MEDLINE
Asunto principal:
Pruebas Diagnósticas de Rutina
Tipo de estudio:
Diagnostic_studies
/
Risk_factors_studies
Límite:
Humans
Idioma:
En
Revista:
BMC Med Res Methodol
Asunto de la revista:
MEDICINA
Año:
2024
Tipo del documento:
Article
País de afiliación:
Estados Unidos