Statistical Quality Control of HIV-1 ELISA Test Performance

By Gentleman, R. C.; Hamada, M. S. et al. | Journal of the American Statistical Association, December 1994 | Go to article overview

Statistical Quality Control of HIV-1 ELISA Test Performance


Gentleman, R. C., Hamada, M. S., Matthews, D. E., Wilson, A. R., Journal of the American Statistical Association


A. R. WILSON*

Ensuring the quality and performance of human immunodeficiency virus, type 1 (HIV-l) enzyme-linked immunosorbent assay (ELISA) testing in routine laboratory Situations is an important practical concern. In this article we develop statistical quality control procedures designed to monitor test performance of the microplates being processed. First, the logarithm of measured optical density is shown to be a more appropriate scale on which to work. Shewhart control charts are considered but are not entirely satisfactory because of between-plate variation. Correct classification depends more on within-plate variation than on between-plate variation. Range charts are useful, but they do not directly indicate whether the results from any particular microplate are reliable. Consequently, a new statistical control chart--the separation chart--is proposed, and the assumptions on which it is based are empirically verified. Retrospective analysis of nearly 1,300 microplates, using separation and range charts, demonstrate s that these statistical process control methods may represent a potentially useful supplement to the manufacturer's recommended quality control procedures.

KEY WORDS: Control chart; Log transformation; Range and separation charts; t test.

1. INTRODUCTION

Millions of enzyme-linked immunosorbent assays (ELISA's) are performed each year to detect antibodies to the human immunodeficiency virus, type 1 (HIV-1). These tests are carried out by agencies involved in collecting blood for transfusion purposes or by diagnostic laboratories, such as those operated by various levels of government in the interest of public health. If the recent suggestion that U.S. hospitals should test all new patients for evidence of infection with HIV-1 is implemented (see Joyce and Brown 1991), the number of HIV-1 ELISA's carried out will increase markedly.

Schwartz, Dans, and Kinosian (1988) have distinguished between test efficacy (i.e., performance under ideal conditions) and test effectiveness (i.e., performance under average conditions) and have highlighted the important practical concern that test effectiveness represents. Although the manufacturer of a serologic test ensures that the testing procedure can detect seropositive individuals with adequate precision under idealized conditions, the statistical quality control (SQC) procedures that we describe are designed to monitor the performance of the testing procedure under day-to-day conditions. This article focuses on the quality control procedures recommended by the manufacturer. Laboratories typically use additional in-house quality control procedures, which are not considered here.

We begin with a brief description of the ELISA test in Section 2, and identify the need for ongoing quality control. We discuss the fundamental statistical issues in HIV-1 testing, and summarize the implications of these considerations with respect to the monitoring of test performance in Section 3. In Section 4, we describe Shewhart control charts and outline problems that arise when these charts are used in a routine way to monitor HIV-1 ELISA test performance. In Section 5 we propose a new control chart, the separation (T) chart, and suggest that the T chart combined with the range (R) chart directly addresses some key issues in the quality control of ELISA test performance. We present concrete evidence of the value of these new statistical tools in Section 6, where we use T and R charts to retrospectively analyze data collected by the Virology Laboratory of the Ontario Ministry of Health. In the final section, we summarize the insights provided by these investigations into statistical tools for quality co ntrol of ELISA test performance.

2. DESCRIPTION OF THE HIV-1 ELISA

A discussion of methods of ensuring satisfactory assay performance on a routine basis requires an understanding of the basic steps involved in obtaining an ELISA result. …

The rest of this article is only available to active members of Questia

Already a member? Log in now.

Notes for this article

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Default project is now your active project.
Project items

Items saved from this article

This article has been saved
Highlights (0)
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

Citations (0)
Some of your citations are legacy items.

Any citation created before July 30, 2012 will labeled as a “Cited page.” New citations will be saved as cited passages, pages or articles.

We also added the ability to view new citations from your projects or the book or article where you created them.

Notes (0)
Bookmarks (0)

You have no saved items from this article

Project items include:
  • Saved book/article
  • Highlights
  • Quotes/citations
  • Notes
  • Bookmarks
Notes
Cite this article

Cited article

Style
Citations are available only to our active members.
Buy instant access to cite pages or passages in MLA, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited article

Statistical Quality Control of HIV-1 ELISA Test Performance
Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this article

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Help
Full screen

matching results for page

    Questia reader help

    How to highlight and cite specific passages

    1. Click or tap the first word you want to select.
    2. Click or tap the last word you want to select, and you’ll see everything in between get selected.
    3. You’ll then get a menu of options like creating a highlight or a citation from that passage of text.

    OK, got it!

    Cited passage

    Style
    Citations are available only to our active members.
    Buy instant access to cite pages or passages in MLA, APA and Chicago citation styles.

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

    1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

    Cited passage

    Thanks for trying Questia!

    Please continue trying out our research tools, but please note, full functionality is available only to our active members.

    Your work will be lost once you leave this Web page.

    Buy instant access to save your work.

    Already a member? Log in now.

    Author Advanced search

    Oops!

    An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.