Evidence map›Paper›PMID 27547730›Full record

ArticleCurrent Metabolomics

PCA as a practical indicator of OPLS-DA model reliability.

Bradley Worley, Robert Powers

Abstract read
In one paragraph

Article in Current Metabolomics. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 183 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
183citing papers in PubMed, 1 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

183 citing papers in PubMed, 1 synthesis or guideline pooled it.

  1. Pooled it
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  10. DietaryAnimals : an open access journal from MDPI · 2026
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  14. Lifestyles, metabolome and diabetic kidney disease: a cohort study.QJM : monthly journal of the Association of Physicians · 2026
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123 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

2 authors.

Bradley WorleyDepartment of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0304.
Robert PowersDepartment of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0304.

Funding

The S. aureus biofilm lifecycleP01AI083211 · NIAID · UNIVERSITY OF NEBRASKA MEDICAL CENTER · PI HANDKE, LUKE D · 2009 to 2023
$32.1M
Targeting Tumor-Stromal Metabolic Cross-Talk in Pancreatic CancerR01CA163649 · NCI · UNIVERSITY OF OKLAHOMA HLTH SCIENCES CTR · PI Pankaj Kumar Singh · 2012 to 2026
$5.4M
Redox Biology CenterP30GM103335 · NIGMS · UNIVERSITY OF NEBRASKA LINCOLN · PI BECKER, DONALD F · 2012 to 2016
$4.3M
EXTRAMURAL RESEARCH FACILITIES CONSTRUCTIONC06RR015468 · NCRR · UNIVERSITY OF NEBRASKA LINCOLN · PI PAUL, PREM S · 2000 to 2000
$2.0M
NCI NIH HHS R01 CA163649NCRR NIH HHS C06 RR015468NIAID NIH HHS P01 AI083211NIGMS NIH HHS P30 GM103335
6 · The paper itself

Abstract

backgroundPrincipal Component Analysis (PCA) and Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) are powerful statistical modeling tools that provide insights into separations between experimental groups based on high-dimensional spectral measurements from NMR, MS or other analytical instrumentation. However, when used without validation, these tools may lead investigators to statistically unreliable conclusions. This danger is especially real for Partial Least Squares (PLS) and OPLS, which aggressively force separations between experimental groups. As a result, OPLS-DA is often used as an alternative method when PCA fails to expose group separation, but this practice is highly dangerous. Without rigorous validation, OPLS-DA can easily yield statistically unreliable group separation.

methodsA Monte Carlo analysis of PCA group separations and OPLS-DA cross-validation metrics was performed on NMR datasets with statistically significant separations in scores-space. A linearly increasing amount of Gaussian noise was added to each data matrix followed by the construction and validation of PCA and OPLS-DA models.

resultsWith increasing added noise, the PCA scores-space distance between groups rapidly decreased and the OPLS-DA cross-validation statistics simultaneously deteriorated. A decrease in correlation between the estimated loadings (added noise) and the true (original) loadings was also observed. While the validity of the OPLS-DA model diminished with increasing added noise, the group separation in scores-space remained basically unaffected.

conclusionSupported by the results of Monte Carlo analyses of PCA group separations and OPLS-DA cross-validation metrics, we provide practical guidelines and cross-validatory recommendations for reliable inference from PCA and OPLS-DA models.

Indexed as

ChemometricsMetabolomicsOPLSPCAPLS

Identifiers

PMID27547730
PMCPMC4990351

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.