Likelihood ratios: getting diagnostic testing into perspective

Likelihood ratios: getting diagnostic testing into perspective.

In modern medicine, sophisticated laboratory tests and imaging studies are often emphasized at the expense of history and physical examination, rather than complementing clinical assessment. Ancillary testing often fails to advance the diagnostic process, and increases patient risk and the expense of medical care. The relative value of clinical evaluation and technological methods is rarely con...

Making sense of diagnostic test likelihood ratios.

part 3: positive and negative likelihood ratios of diagnostic tests

in the previous two parts of educational manuscript series in emergency, we explained some screening characteristics of diagnostic tests including accuracy, sensitivity, specificity, and positive and negative predictive values. in the 3rd  part we aimed to explain positive and negative likelihood ratio (lr) as one of the most reliable performance measures of a diagnostic test. to better underst...

System Perspective on Diagnostic Testing

Testing is performed for a variety of reasons-performance verification, experimentation, manufacturing assurance, diagnosis, process improvement, etc. Tlhe growing complexity of full-scale systems has outstripped our ability to provide detailed simulations for micro level diagnosis. When we have completed the experimentation and the verification through brass-board, we begin full scale engineer...

Inferences for Likelihood Ratios

Likelihood ratios are extensively used to evaluate the performances of diagnostic tests and to update prior odds of disease to posttest odds. Since few tests are truly 100% accurate, including many used as “gold standards,” it is important to be able to estimate likelihood ratios in cases where no such standard is available. In this paper, methods to calculate point and interval estimates for l...