<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE article PUBLIC "-//NLM//DTD Journal Publishing DTD v2.0 20040830//EN" "journalpublishing.dtd"><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" dtd-version="2.0" xml:lang="en" article-type="reviewer-report"><front><journal-meta><journal-id journal-id-type="nlm-ta">JMIRx Med</journal-id><journal-id journal-id-type="publisher-id">xmed</journal-id><journal-id journal-id-type="index">34</journal-id><journal-title>JMIRx Med</journal-title><abbrev-journal-title>JMIRx Med</abbrev-journal-title><issn pub-type="epub">2563-6316</issn><publisher><publisher-name>JMIR Publications</publisher-name><publisher-loc>Toronto, Canada</publisher-loc></publisher></journal-meta><article-meta><article-id pub-id-type="publisher-id">v6i1e90221</article-id><article-id pub-id-type="doi">10.2196/90221</article-id><article-categories><subj-group subj-group-type="heading"><subject>Peer-Review Report</subject></subj-group></article-categories><title-group><article-title>Peer Review of &#x201C;Investigating the Variable Component of the Systematic Error, a Neglected Error Parameter: Theoretical Reevaluation Study&#x201D;</article-title></title-group><contrib-group><contrib contrib-type="author"><collab>Anonymous</collab></contrib></contrib-group><contrib-group><contrib contrib-type="editor"><name name-style="western"><surname>Leung</surname><given-names>Tiffany</given-names></name></contrib></contrib-group><pub-date pub-type="collection"><year>2026</year></pub-date><pub-date pub-type="epub"><day>27</day><month>2</month><year>2026</year></pub-date><volume>6</volume><elocation-id>e90221</elocation-id><history><date date-type="received"><day>23</day><month>12</month><year>2025</year></date><date date-type="accepted"><day>23</day><month>12</month><year>2025</year></date></history><copyright-statement>&#x00A9; Anonymous. Originally published in JMIRx Med (<ext-link ext-link-type="uri" xlink:href="https://med.jmirx.org">https://med.jmirx.org</ext-link>), 27.2.2026. </copyright-statement><copyright-year>2026</copyright-year><license license-type="open-access" xlink:href="https://creativecommons.org/licenses/by/4.0/"><p>This is an open-access article distributed under the terms of the Creative Commons Attribution License (<ext-link ext-link-type="uri" xlink:href="https://creativecommons.org/licenses/by/4.0/">https://creativecommons.org/licenses/by/4.0/</ext-link>), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in JMIRx Med, is properly cited. The complete bibliographic information, a link to the original publication on <ext-link ext-link-type="uri" xlink:href="https://med.jmirx.org/">https://med.jmirx.org/</ext-link>, as well as this copyright and license information must be included.</p></license><self-uri xlink:type="simple" xlink:href="https://xmed.jmir.org/2026/1/e90221"/><related-article related-article-type="companion" ext-link-type="doi" xlink:href="10.1101/2023.05.24.23290382" xlink:title="Preprint (medRxiv)" xlink:type="simple">https://www.medrxiv.org/content/10.1101/2023.05.24.23290382v1</related-article><related-article related-article-type="companion" ext-link-type="doi" xlink:href="10.2196/88981" xlink:title="Author's Response to Peer-Review Reports" xlink:type="simple">https://med.jmirx.org/2026/1/e88981</related-article><related-article related-article-type="companion" ext-link-type="doi" xlink:href="10.2196/49657" xlink:title="Published Article" xlink:type="simple">https://med.jmirx.org/2026/1/e49657</related-article><kwd-group><kwd>repeatability condition</kwd><kwd>reproducibility within laboratory condition, measurement</kwd><kwd>systematic error</kwd><kwd>clinical laboratory</kwd><kwd>quality control</kwd><kwd>bias</kwd><kwd>QC</kwd><kwd>statistical</kwd><kwd>statistics</kwd><kwd>mathematics</kwd><kwd>computer simulation</kwd><kwd>standard deviation</kwd></kwd-group></article-meta></front><body><p><italic>This is the peer-review report for &#x201C;Investigating the Variable Component of the Systematic Error, a Neglected Error Parameter: Theoretical Reevaluation Study.&#x201D;</italic></p><sec id="s2"><title>Round 1 Review</title><sec id="s1-1"><title>General Comments</title><p>With an emphasis on the idea of VCSE(t) (variation in control sample error over time), the study [<xref ref-type="bibr" rid="ref1">1</xref>] provides a thorough examination of variation in laboratory data. The study emphasizes the significance of differentiating between random and systematic errors, suggests fresh approaches for precisely calculating sVCSE (an SD), and supports updated quality control procedures.</p></sec><sec id="s1-2"><title>Specific Comments</title><sec id="s1-2-1"><title>Major Comments</title><list list-type="simple"><list-item><p>1. The study does not provide empirical confirmation of suggested approaches using real-world data, although it mentions computer simulations and experimental verification. The suggested methodologies&#x2019; efficacy and dependability are yet unknown in the absence of empirical validation.</p></list-item><list-item><p>2. Linear drifts in daily means across time are assumed in the study. Numerous factors, such as the environment, instrument calibration, and reagent stability, can affect real-world drift patterns and lead to nonlinear trends in daily means over time. The study might have simplified the complicated nature of drift processes by assuming linearity, which could result in estimates of mean values and error components that are not true.</p></list-item><list-item><p>3. The assumption that information from internal quality control sources alone can be used to accurately calculate VCSE(t) is inaccurate. Even though internal quality control data offer insightful information on short-term variability, they might not include all sources of variation, particularly those pertaining to outside variables like shifts in the environment, instrument performance, or operator technique. Ignoring these outside influences could result in an inaccurate or understated VCSE(t), which would compromise the validity of the suggested quality control techniques.</p></list-item></list></sec><sec id="s1-2-2"><title>Minor Comments</title><list list-type="simple"><list-item><p>1. Although there is a suggestion in the Conclusions section that the present quality control paradigm needs to be revised, there is no concrete plan or set of recommendations based on statistical or mathematical concepts.</p></list-item><list-item><p>2. The paper lacks a Discussion section, which could have allowed the author to interpret and contextualize the study&#x2019;s findings. Additionally, it could have provided an opportunity to compare the study&#x2019;s findings with previous studies, discuss their implications, and address potential sources of error or bias.</p></list-item></list></sec></sec></sec></body><back><fn-group><fn fn-type="conflict"><p>None declared.</p></fn></fn-group><glossary><title>Abbreviations</title><def-list><def-item><term id="abb1">VCSE(t)</term><def><p>variation in control sample error over time</p></def></def-item></def-list></glossary><ref-list><title>References</title><ref id="ref1"><label>1</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Vandra</surname><given-names>AB</given-names> </name></person-group><article-title>Investigating the variable component of the systematic error, a neglected error parameter: theoretical reevaluation study</article-title><source>JMIRx Med</source><year>2026</year><volume>7</volume><fpage>e49657</fpage><pub-id pub-id-type="doi">10.2196/49657</pub-id></nlm-citation></ref></ref-list></back></article>