The two-step Fagan's nomogram: ad hoc interpretation of a diagnostic test result without calculation.
Evid Based Med
; 18(4): 125-8, 2013 Aug.
Article
en En
| MEDLINE
| ID: mdl-23468201
ABSTRACT
In 1975, Fagan published a nomogram to help practitioners determine, without the use of a calculator or computer, the probability of a patient truly having a condition of interest given a particular test result. Nomograms are very useful for bedside interpretations of test results, as no test is perfect. However, the practicality of Fagan's nomogram is limited by its use of the likelihood ratio (LR), a parameter not commonly reported in the evaluation studies of diagnostic tests. The LR reflects the direction and strength of evidence provided by a test result and can be computed from the conventional diagnostic sensitivity (DSe) and specificity (DSp) of the test. This initial computation is absent in Fagan's nomogram, making it impractical for routine use. We have seamlessly integrated the initial step to compute the LR and the resulting two-step nomogram allows the user to quickly interpret the outcome of a test. With the addition of the DSe and DSp, the nomogram, for the purposes of interpreting a dichotomous test result, is now complete. This tool is more accessible and flexible than the original, which will facilitate its use in routine evidence-based practice. The nomogram can be downloaded at www.adelaide.edu.au/vetsci/research/pub_pop/2step-nomogram/.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Técnicas de Laboratorio Clínico
/
Nomogramas
Tipo de estudio:
Diagnostic_studies
/
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
Evid Based Med
Asunto de la revista:
MEDICINA
Año:
2013
Tipo del documento:
Article
País de afiliación:
Australia