How many glomerular profiles must be measured to obtain reliable estimates of mean glomerular areas in human renal biopsies?

Hoy, Wendy E., Samuel, Terence, Nicol, Jennifer L. and Bertram, John F. (2006) How many glomerular profiles must be measured to obtain reliable estimates of mean glomerular areas in human renal biopsies?. Journal Of The American Society Of Nephrology, 17 2: 556-563. doi:10.1681/ASN.2005070772

Author Hoy, Wendy E.
Samuel, Terence
Nicol, Jennifer L.
Bertram, John F.
Title How many glomerular profiles must be measured to obtain reliable estimates of mean glomerular areas in human renal biopsies?
Journal name Journal Of The American Society Of Nephrology   Check publisher's open access policy
ISSN 1046-6673
Publication date 2006-02-01
Year available 2006
Sub-type Article (original research)
DOI 10.1681/ASN.2005070772
Open Access Status Not Open Access
Volume 17
Issue 2
Start page 556
End page 563
Total pages 8
Place of publication Washington, D.C., USA
Publisher American Society of Nephrology
Language eng
Subject CX
321012 Nephrology and Urology
730115 Urogenital system and disorders
1103 Clinical Sciences
Abstract The objective of this study was to investigate the number of glomerular profiles that are required for accurate estimates of mean profile area in a renal biopsy series. Slides from 384 renal biopsies from one center were reviewed. They contained a median of seven glomerular profiles or of four profiles without sclerosis. Profile areas were measured using stereologic point counting. The true individual mean for each biopsy was calculated and the true population mean for groups of biopsies derived. Individual and population random sample means then were calculated from a random sampling of profiles in each biopsy and were compared with true means for the same biopsies. The effect on the true population means of the entire group of biopsies was also assessed, as the minimum number of glomerular profiles that were required for inclusion was changed. In a single biopsy, random sampling of >= 10 profiles without exclusions and of eight profiles or more without sclerosis reliably estimated the true mean areas. In a group of 30 biopsies, random sampling of five or more glomeruli per biopsy reliably estimated the true population mean. In the aggregate series, inclusion of all 384 biopsies produced the most robust true population mean; the reliability of the estimates decreased as the numbers of eligible biopsies diminished with increasing requisite minimum numbers of profiles per biopsy. We conclude that, while >= 10 profiles might be needed for reliable area estimates in a single biopsy, far fewer profiles per biopsy can suffice when groups of biopsies are studied. In analyses of groups of biopsies, all available biopsies should be used without consideration of the number of glomerular profiles in each. Stipulation of a specific minimum number of glomeruli in each biopsy for inclusion reduces the power of analyses because fewer biopsies are available for evaluation.
Keyword Urology & nephrology
Diabetic nephropathy
Q-Index Code C1
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Excellence in Research Australia (ERA) - Collection
School of Medicine Publications
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 17 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 18 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Wed, 15 Aug 2007, 19:44:22 EST