- Email: [email protected]
Reply to the comments raised by Soldin
Clinica Chimica Acta 412 (2011) 484
Contents lists available at ScienceDirect
Clinica Chimica Acta j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / c l i n c h i m
Reply to the letter to the editor Reply to the comments raised by Soldin We reply to the criticism by Soldin et al. on the scientific design of our study. We performed an analytical study, which fully justifies the crosssectional study design. It was not our aim to determine reference intervals, thus there was no need that the sample size adhered to the recommendations by the IFCC or NCCLS. On the other hand, being fully aware of the importance of a sufficient sample size to generate data with statistic significance, we performed power calculations, using the expected differences between the groups and the expected variances of the groups. The results fully support that the sample size was sufficient, the more, because they are in very good agreement with much larger studies. The remark that the study required patients with hyperthyroidism and hypothyroidism is not relevant since the aim of the study was to compare automated FT4 immunoassays with an ED ID-LC/tandem MS candidate reference measurement procedure for analysis of samples from pregnant females versus non-pregnant controls. The correlation of FT4 with TSH was not relevant for our study. The method based on equilibrium dialysis ID-LC/tandem MS was fully validated. We refer to: Van Uytfanghe K, Stöckl D, Ross HA, Thienpont LM. Use of Frozen Sera for FT4 Standardization: Investigation by Equilibrium Dialysis Combined with Isotope Dilution-Mass Spectrometry and Immunoassay. Clin Chem 2006;52:1817–21 (see also: 070425. Supplemental Data).
0009-8981/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.cca.2010.11.001
We followed the rules of the journal regarding the declaration for project funding. Ellen Anckaert Laboratory of Clinical Chemistry and Radio-immunology, UZ Brussel, Brussel, Belgium Corresponding author. E-mail address: [email protected]. Kris Poppe Department of Endocrinology, UZ Brussel, Brussel, Belgium Katleen Van Uytfanghe Laboratory for Analytical Chemistry, University of Ghent, Gent, Belgium Johan Schiettecatte Laboratory of Clinical Chemistry and Radio-immunology, UZ Brussel, Brussel, Belgium Walter Foulon Department of Obstetrics, UZ Brussel, Brussel, Belgium Linda M. Thienpont Laboratory for Analytical Chemistry, University of Ghent, Gent, Belgium
Contents lists available at ScienceDirect
Clinica Chimica Acta j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / c l i n c h i m
Reply to the letter to the editor Reply to the comments raised by Soldin We reply to the criticism by Soldin et al. on the scientific design of our study. We performed an analytical study, which fully justifies the crosssectional study design. It was not our aim to determine reference intervals, thus there was no need that the sample size adhered to the recommendations by the IFCC or NCCLS. On the other hand, being fully aware of the importance of a sufficient sample size to generate data with statistic significance, we performed power calculations, using the expected differences between the groups and the expected variances of the groups. The results fully support that the sample size was sufficient, the more, because they are in very good agreement with much larger studies. The remark that the study required patients with hyperthyroidism and hypothyroidism is not relevant since the aim of the study was to compare automated FT4 immunoassays with an ED ID-LC/tandem MS candidate reference measurement procedure for analysis of samples from pregnant females versus non-pregnant controls. The correlation of FT4 with TSH was not relevant for our study. The method based on equilibrium dialysis ID-LC/tandem MS was fully validated. We refer to: Van Uytfanghe K, Stöckl D, Ross HA, Thienpont LM. Use of Frozen Sera for FT4 Standardization: Investigation by Equilibrium Dialysis Combined with Isotope Dilution-Mass Spectrometry and Immunoassay. Clin Chem 2006;52:1817–21 (see also: 070425. Supplemental Data).
0009-8981/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.cca.2010.11.001
We followed the rules of the journal regarding the declaration for project funding. Ellen Anckaert Laboratory of Clinical Chemistry and Radio-immunology, UZ Brussel, Brussel, Belgium Corresponding author. E-mail address: [email protected]. Kris Poppe Department of Endocrinology, UZ Brussel, Brussel, Belgium Katleen Van Uytfanghe Laboratory for Analytical Chemistry, University of Ghent, Gent, Belgium Johan Schiettecatte Laboratory of Clinical Chemistry and Radio-immunology, UZ Brussel, Brussel, Belgium Walter Foulon Department of Obstetrics, UZ Brussel, Brussel, Belgium Linda M. Thienpont Laboratory for Analytical Chemistry, University of Ghent, Gent, Belgium