Sensitivity studies for quantitative assays: use of censored data analysis
Article first published online: 14 NOV 2003
Copyright © 2003 John Wiley & Sons, Ltd.
Statistics in Medicine
Volume 22, Issue 23, pages 3629–3640, 15 December 2003
How to Cite
Weusten, J. J. A. M., Wouters, P. A. W. M. and van Zuijlen, M. C. A. (2003), Sensitivity studies for quantitative assays: use of censored data analysis. Statist. Med., 22: 3629–3640. doi: 10.1002/sim.1584
- Issue published online: 14 NOV 2003
- Article first published online: 14 NOV 2003
- Manuscript Accepted: MAR 2003
- Manuscript Received: FEB 2002
- probit analysis;
- censored data;
Probit regression analysis is frequently used to study the relation between the concentration of an analyte in a sample and the probability that the assay used yields a positive test result. For these analyses only the qualitative classification ‘positive’ or ‘negative’ is used, whereas, particularly in the case where the assay is quantitative in nature, the results contain more information. In the current paper, we propose an alternative method, in which the negative test results are treated as being (left) censored. As such, more efficient use is made of the information in the data. The procedures are illustrated using two generations of NucliSens assays (BioMérieux), which are designed to quantify the viral load of HIV-1 in blood samples. Computer simulations are used to illustrate some properties of the estimated parameters. Copyright © 2003 John Wiley & Sons, Ltd.