Statistical methods for the assessment of EQAPOL proficiency testing: ELISpot, Luminex, and Flow Cytometry.
Abstract
In September 2011 Duke University was awarded a contract to develop the National Institutes
of Health/National Institute of Allergy and Infectious Diseases (NIH/NIAID) External
Quality Assurance Program Oversight Laboratory (EQAPOL). Through EQAPOL, proficiency
testing programs are administered for Interferon-γ (IFN-γ) Enzyme-linked immunosorbent
spot (ELISpot), Intracellular Cytokine Staining Flow Cytometry (ICS) and Luminex-based
cytokine assays. One of the charges of the EQAPOL program was to apply statistical
methods to determine overall site performance. We utilized various statistical methods
for each program to find the most appropriate for assessing laboratory performance
using the consensus average as the target value. Accuracy ranges were calculated based
on Wald-type confidence intervals, exact Poisson confidence intervals, or via simulations.
Given the nature of proficiency testing data, which has repeated measures within donor/sample
made across several laboratories; the use of mixed effects models with alpha adjustments
for multiple comparisons was also explored. Mixed effects models were found to be
the most useful method to assess laboratory performance with respect to accuracy to
the consensus. Model based approaches to the proficiency testing data in EQAPOL will
continue to be utilized. Mixed effects models also provided a means of performing
more complex analyses that would address secondary research questions regarding within
and between laboratory variability as well as longitudinal analyses.
Type
Journal articleSubject
ELISpotFlow Cytometry
Luminex
Mixed effects models
Poisson
Proficiency testing
Biomarkers
Cytokines
Data Interpretation, Statistical
Enzyme-Linked Immunospot Assay
Flow Cytometry
Guideline Adherence
Humans
Interferon-gamma Release Tests
Laboratories
Laboratory Proficiency Testing
Models, Statistical
Monitoring, Immunologic
Observer Variation
Practice Guidelines as Topic
Predictive Value of Tests
Program Development
Program Evaluation
Quality Control
Quality Indicators, Health Care
Reproducibility of Results
Specimen Handling
Permalink
https://hdl.handle.net/10161/14689Published Version (Please cite this version)
10.1016/j.jim.2014.01.007Publication Info
Rountree, Wes; Vandergrift, Nathan; Bainbridge, John; Sanchez, Ana M; & Denny, Thomas
N (2014). Statistical methods for the assessment of EQAPOL proficiency testing: ELISpot, Luminex,
and Flow Cytometry. Journal of Immunological Methods, 409. pp. 72-81. 10.1016/j.jim.2014.01.007. Retrieved from https://hdl.handle.net/10161/14689.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
Collections
More Info
Show full item recordScholars@Duke
Thomas Norton Denny
Professor in Medicine
Thomas N. Denny, MSc, M.Phil, is the Chief Operating Officer of the Duke Human Vaccine
Institute (DHVI), Associate Dean for Duke Research and Discovery @RTP, and a Professor
of Medicine in the Department of Medicine at Duke University Medical Center. He is
also an Affiliate Member of the Duke Global Health Institute. Previously, he served
on the Health Sector Advisory Council of the Duke University Fuquay School of Business.
Prior to joining Duke, he was an Associate Professor of Pathology, Labo
Nathan A. Vandergrift
Associate Professor in Medicine
Alphabetical list of authors with Scholars@Duke profiles.

Articles written by Duke faculty are made available through the campus open access policy. For more information see: Duke Open Access Policy
Rights for Collection: Scholarly Articles
Works are deposited here by their authors, and represent their research and opinions, not that of Duke University. Some materials and descriptions may include offensive content. More info