CoChat
Sign Up
Cited by 131Hormonal and reproductive studiesSperm and Testicular FunctionAdrenal Hormones and Disorders

The DOI matches its Crossref record; 44 of the 44 references it cites were found in a registry or an index.

Calculation of Bioavailable and Free Testosterone in Men: A Comparison of 5 Published Algorithms

de Ronde, Willem, van der Schouw, Yvonne T, Pols, Huibert AP, Gooren, Louis JG, Muller, Majon, Grobbee, Diederick E, de Jong, Frank H·2006·Clinical Chemistry
DOI 10.1373/clinchem.2005.063354
Open this paper in CoChat — free account

Abstract

Background: Estimation of serum concentrations of free testosterone (FT) and bioavailable testosterone (bioT) by calculation is an inexpensive and uncomplicated method. We compared results obtained with 5 different algorithms. Methods: We used 5 different published algorithms [described by Sodergard et al. (bioTS and FTS), Vermeulen et al. (bioTV and FTV), Emadi-Konjin et al. (bioTE), Morris et al. (bioTM), and Ly et al. (FTL)] to estimate bioT and FT concentrations in samples obtained from 399 independently living men (ages 40–80 years) participating in a cross-sectional, single-center study. Results: Mean bioT was highest for bioTS (10.4 nmol/L) and lowest for bioTE (3.87 nmol/L). Mean FT was highest for FTS (0.41 nmol/L), followed by FTV (0.35 nmol/L), and FTL (0.29 nmol/L). For bioT concentrations, the Pearson correlation coefficient was highest for the association between bioTS and bioTV (r = 0.98) and lowest between bioTM and bioTE (r = 0.66). FTL was significantly associated with both FTS (r = 0.96) and FTV (r = 0.88). The Pearson correlation coefficient for the association between FTL and bioTM almost reached 1.0. Bland-Altman analysis showed large differences between the results of different algorithms. BioTM, bioTE, bioTV, and FTL were all significantly associated with sex hormone binding globulin (SHBG) concentrations. Conclusion: Algorithms to calculate FT and bioT must be revalidated in the local setting, otherwise over- or underestimation of FT and bioT concentrations can occur. Additionally, confounding of the results by SHBG concentrations may be introduced.

Overview

Integrity signals

Registry

Crossref · 10.1373/clinchem.2005.063354

Cites

44 of 44 references verified0 citation errors · 0 not checkable

Statistics

Recomputing p-values needs the paper’s full text.

Verification

Claims the paper makes

This paper’s full text isn’t openly available, so its claims and self-check weren’t run. The registry and citation checks still apply.

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Citations

Cites

Flagged first, then by citations

Show all 44 references

Cited by

Sorted by citations

Items 101–131 of 131

Related

See all

Metadata

Authors
de Ronde, W., van der Schouw, Y. T., Pols, H. A., Gooren, L. J., Muller, M., Grobbee, D. E., & de Jong, F. H.
Affiliations
  • Department of Endocrinology, Vrije Universiteit Medical Center, Amsterdam, The Netherlands
  • Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, The Netherlands
  • Erasmus MC (NL)
  • Amsterdam UMC Location Vrije Universiteit Amsterdam (NL)
  • University Medical Center Utrecht (NL)
  • Departments of Internal Medicine; and Epidemiology and Biostatistics, Erasmus Medical Center, Rotterdam, The Netherlands
ORCID
Venue
Clinical Chemistry
Publisher
Oxford University Press (OUP)
Published
2006-09-01
Volume
52
Issue
9
Pages
1777-1784
ISSN
  • 0009-9147 (ISSN-L)
  • 1530-8561
DOI
10.1373/clinchem.2005.063354
OpenAlex
W2108328747
Cited by
131
References
44
Citations by year
2026: 3 · 2025: 4 · 2024: 2 · 2023: 4 · 2022: 3 · 2021: 8 · 2020: 5 · 2019: 4 · 2018: 5 · 2017: 12 · 2016: 3 · 2015: 8 · 2014: 9 · 2013: 10 · 2012: 7
FWCI
6.11
Type
journal article
Language
en
Open access
closed
Licence
academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model (vor)
Locations
  • Clinical Chemistry (publishedVersion)
  • PubMed (publishedVersion)
  • Pure Amsterdam UMC (publishedVersion)
  • Amsterdam UMC (VU Amsterdam) - Institutional Repository (publishedVersion)
  • EUR Research Repository (Erasmus University Rotterdam) (publishedVersion)
  • EUR Research Repository (Erasmus University Rotterdam) (submittedVersion)
  • Data Archiving and Networked Services (DANS) (submittedVersion)
Topics
  • Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Hormonal and reproductive studies
  • Health Sciences › Medicine › Reproductive Medicine › Sperm and Testicular Function
  • Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Adrenal Hormones and Disorders
Keywords
free testosterone, bioavailable testosterone, sex hormone-binding globulin, algorithm comparison, men, algorithm validation
MeSH terms
Adult, Aged, Aged, 80 and over, Algorithms, Carrier Proteins, Cross-Sectional Studies, Humans, Male, Middle Aged, Serum Albumin, Sex Hormone-Binding Globulin, Testosterone

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review