Accuracy in using dual-isotope Schilling test to measure urine samples: A multicenter study

B. R. Krynyckyi, L. S. Zuckier

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

As a component of our quality assurance program, this multicenter study was performed to characterize the magnitude and types of error present in measurement of typical dual-isotope Schilling test (DIST) urine samples. Methods: A panel of three simulated DIST urine samples was formulated corresponding to diagnoses of normal excretion, malabsorption and pernicious anemia and was distributed to eight hospitals in our regional area (three novice and five experienced users). Count-rate data and urine volume measurements from each site were analyzed for accuracy against the predicted values and a carefully measured gold standard and were correlated with the methodology and equipment used. Results: Three of 24 results were uninterpretable due to an overly low ratio of intrinsic factor bound to free vitamin B12 excretion (B/F ratio), inconsistent with possible diagnoses. In 20 of 21 interpretable samples, results corresponded to the appropriate diagnoses, with typical values noted in 18 of the cases and slightly atypical yet diagnostic values seen in the remaining two cases. In only one sample did values correspond to an erroneous diagnosis (low normal or partial malabsorption rather than pernicious anemia). The four major discrepancies (test failure or misdiagnosis) were largely attributable to blunders and were limited to two of the three novice sites and to a single experienced site which had grossly inaccurate raw data (background greater than sample counts). Conclusion: Quantitation of vitamin B12 excretion in DIST urine samples is a reliable method of evaluation when performed by reasonably experienced and competent clinical laboratories. Improved accuracy may be obtained by increasing the stochastic certainty of the count data and by more careful measurement of the sample and urine volumes.

Original languageEnglish (US)
Pages (from-to)1659-1665
Number of pages7
JournalJournal of Nuclear Medicine
Volume36
Issue number9
StatePublished - Sep 18 1995

Fingerprint

Schilling Test
Isotopes
Multicenter Studies
Urine
Pernicious Anemia
Vitamin B 12
Intrinsic Factor
Diagnostic Errors
Equipment and Supplies

Keywords

  • dual-isotope studies
  • quality assurance
  • Schilling test
  • urine measurement

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

Cite this

Accuracy in using dual-isotope Schilling test to measure urine samples : A multicenter study. / Krynyckyi, B. R.; Zuckier, L. S.

In: Journal of Nuclear Medicine, Vol. 36, No. 9, 18.09.1995, p. 1659-1665.

Research output: Contribution to journalArticle

@article{cdade08c94054d08b30a97776b880cba,
title = "Accuracy in using dual-isotope Schilling test to measure urine samples: A multicenter study",
abstract = "As a component of our quality assurance program, this multicenter study was performed to characterize the magnitude and types of error present in measurement of typical dual-isotope Schilling test (DIST) urine samples. Methods: A panel of three simulated DIST urine samples was formulated corresponding to diagnoses of normal excretion, malabsorption and pernicious anemia and was distributed to eight hospitals in our regional area (three novice and five experienced users). Count-rate data and urine volume measurements from each site were analyzed for accuracy against the predicted values and a carefully measured gold standard and were correlated with the methodology and equipment used. Results: Three of 24 results were uninterpretable due to an overly low ratio of intrinsic factor bound to free vitamin B12 excretion (B/F ratio), inconsistent with possible diagnoses. In 20 of 21 interpretable samples, results corresponded to the appropriate diagnoses, with typical values noted in 18 of the cases and slightly atypical yet diagnostic values seen in the remaining two cases. In only one sample did values correspond to an erroneous diagnosis (low normal or partial malabsorption rather than pernicious anemia). The four major discrepancies (test failure or misdiagnosis) were largely attributable to blunders and were limited to two of the three novice sites and to a single experienced site which had grossly inaccurate raw data (background greater than sample counts). Conclusion: Quantitation of vitamin B12 excretion in DIST urine samples is a reliable method of evaluation when performed by reasonably experienced and competent clinical laboratories. Improved accuracy may be obtained by increasing the stochastic certainty of the count data and by more careful measurement of the sample and urine volumes.",
keywords = "dual-isotope studies, quality assurance, Schilling test, urine measurement",
author = "Krynyckyi, {B. R.} and Zuckier, {L. S.}",
year = "1995",
month = "9",
day = "18",
language = "English (US)",
volume = "36",
pages = "1659--1665",
journal = "Journal of Nuclear Medicine",
issn = "0161-5505",
publisher = "Society of Nuclear Medicine Inc.",
number = "9",

}

TY - JOUR

T1 - Accuracy in using dual-isotope Schilling test to measure urine samples

T2 - A multicenter study

AU - Krynyckyi, B. R.

AU - Zuckier, L. S.

PY - 1995/9/18

Y1 - 1995/9/18

N2 - As a component of our quality assurance program, this multicenter study was performed to characterize the magnitude and types of error present in measurement of typical dual-isotope Schilling test (DIST) urine samples. Methods: A panel of three simulated DIST urine samples was formulated corresponding to diagnoses of normal excretion, malabsorption and pernicious anemia and was distributed to eight hospitals in our regional area (three novice and five experienced users). Count-rate data and urine volume measurements from each site were analyzed for accuracy against the predicted values and a carefully measured gold standard and were correlated with the methodology and equipment used. Results: Three of 24 results were uninterpretable due to an overly low ratio of intrinsic factor bound to free vitamin B12 excretion (B/F ratio), inconsistent with possible diagnoses. In 20 of 21 interpretable samples, results corresponded to the appropriate diagnoses, with typical values noted in 18 of the cases and slightly atypical yet diagnostic values seen in the remaining two cases. In only one sample did values correspond to an erroneous diagnosis (low normal or partial malabsorption rather than pernicious anemia). The four major discrepancies (test failure or misdiagnosis) were largely attributable to blunders and were limited to two of the three novice sites and to a single experienced site which had grossly inaccurate raw data (background greater than sample counts). Conclusion: Quantitation of vitamin B12 excretion in DIST urine samples is a reliable method of evaluation when performed by reasonably experienced and competent clinical laboratories. Improved accuracy may be obtained by increasing the stochastic certainty of the count data and by more careful measurement of the sample and urine volumes.

AB - As a component of our quality assurance program, this multicenter study was performed to characterize the magnitude and types of error present in measurement of typical dual-isotope Schilling test (DIST) urine samples. Methods: A panel of three simulated DIST urine samples was formulated corresponding to diagnoses of normal excretion, malabsorption and pernicious anemia and was distributed to eight hospitals in our regional area (three novice and five experienced users). Count-rate data and urine volume measurements from each site were analyzed for accuracy against the predicted values and a carefully measured gold standard and were correlated with the methodology and equipment used. Results: Three of 24 results were uninterpretable due to an overly low ratio of intrinsic factor bound to free vitamin B12 excretion (B/F ratio), inconsistent with possible diagnoses. In 20 of 21 interpretable samples, results corresponded to the appropriate diagnoses, with typical values noted in 18 of the cases and slightly atypical yet diagnostic values seen in the remaining two cases. In only one sample did values correspond to an erroneous diagnosis (low normal or partial malabsorption rather than pernicious anemia). The four major discrepancies (test failure or misdiagnosis) were largely attributable to blunders and were limited to two of the three novice sites and to a single experienced site which had grossly inaccurate raw data (background greater than sample counts). Conclusion: Quantitation of vitamin B12 excretion in DIST urine samples is a reliable method of evaluation when performed by reasonably experienced and competent clinical laboratories. Improved accuracy may be obtained by increasing the stochastic certainty of the count data and by more careful measurement of the sample and urine volumes.

KW - dual-isotope studies

KW - quality assurance

KW - Schilling test

KW - urine measurement

UR - http://www.scopus.com/inward/record.url?scp=0029080476&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0029080476&partnerID=8YFLogxK

M3 - Article

C2 - 7658228

AN - SCOPUS:0029080476

VL - 36

SP - 1659

EP - 1665

JO - Journal of Nuclear Medicine

JF - Journal of Nuclear Medicine

SN - 0161-5505

IS - 9

ER -