Weighted product index and its two-independent-sample comparison based on weighted sensitivity and specificity

ABSTRACT

Background: On the basis of statistical methods about index S (S = SEN × SPE), we develop a new weighted ways (weighted product index S_w) of combining sensitivity and specificity with user-defined weights. Methods: The new weighted product index S_w is defined as S_w = (SEN) (Youden 1950)^2w × (SPE) (Youden 1950) ^2(1−w) Results: For the large sample, the test statistics Z of two-independent-sample weighted product indices can either be a monotonous increasing/decreasing function or a no-monotonous function of weight w. Type I error of this statistics can be guaranteed close to the nominal level of 5%, which is more conservative than the weighted Youden index from simulation.

KEYWORDS:

• Weighted product index
• diagnostic test
• weights
• sensitivity
• specificity.

Acknowledgments

This work was supported by the grants from the National Nature Science Foundation of China (No. 81402759) and the Natural Science Foundation of Guangdong Province (No. 2015A030310279), and Science and technology development, Southern Medical University (No. KJ20161126).

Additional information

Funding

Natural Science Foundation of Guangdong Province [No. 2015A030310279]; National Nature Science Foundation of China [No. 81402759].