Evidence map›Paper›PMID 29927942›Full record

ArticlePloS one2018

Variable selection in omics data: A practical evaluation of small sample sizes.

Alexander Kirpich, Elizabeth A Ainsworth, Jessica M Wedow, Jeremy R B Newman, George Michailidis, Lauren M McIntyre

Abstract read
In one paragraph

Article in PloS one, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 40 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
40citing 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

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

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  9. Bioactive compound identification without fractionation: an Ocimum spp. case study.Metabolomics : Official journal of the Metabolomic Society · 2025
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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

6 authors.

Alexander KirpichDepartment of Biology, University of Florida, Gainesville, FL, United States of America.
Elizabeth A AinsworthDepartment of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America.
Jessica M WedowDepartment of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America.
Jeremy R B NewmanDepartment of Biology, University of Florida, Gainesville, FL, United States of America.
George MichailidisInformatics Institute, University of Florida, Gainesville, FL, United States of America.
Lauren M McIntyreDepartment of Biology, University of Florida, Gainesville, FL, United States of America.ORCID 0000-0002-0077-3359

Funding

Southeast Resource Center for Integrated Metabolomics (SECIM)U24DK097209 · NIDDK · UNIVERSITY OF FLORIDA · PI EDISON, ARTHUR S, YOST, RICHARD A. · 2013 to 2017
$9.2M
Expression and proteomic characterization of risk loci in type 1 diabetesDP3DK085678 · NIDDK · UNIVERSITY OF VIRGINIA · PI RICH, STEPHEN S. · 2009 to 2009
$6.6M
NIDDK NIH HHS DP3 DK085678NIDDK NIH HHS U24 DK097209
6 · The paper itself

Abstract

In omics experiments, variable selection involves a large number of metabolites/ genes and a small number of samples (the n < p problem). The ultimate goal is often the identification of one, or a few features that are different among conditions- a biomarker. Complicating biomarker identification, the p variables often contain a correlation structure due to the biology of the experiment making identifying causal compounds from correlated compounds difficult. Additionally, there may be elements in the experimental design (blocks, batches) that introduce structure in the data. While this problem has been discussed in the literature and various strategies proposed, the over fitting problems concomitant with such approaches are rarely acknowledged. Instead of viewing a single omics experiment as a definitive test for a biomarker, an unrealistic analytical goal, we propose to view such studies as screening studies where the goal of the study is to reduce the number of features present in the second round of testing, and to limit the Type II error. Using this perspective, the performance of LASSO, ridge regression and Elastic Net was compared with the performance of an ANOVA via a simulation study and two real data comparisons. Interestingly, a dramatic increase in the number of features had no effect on Type I error for the ANOVA approach. ANOVA, even without multiple test correction, has a low false positive rates in the scenarios tested. The Elastic Net has an inflated Type I error (from 10 to 50%) for small numbers of features which increases with sample size. The Type II error rate for the ANOVA is comparable or lower than that for the Elastic Net leading us to conclude that an ANOVA is an effective analytical tool for the initial screening of features in omics experiments.

Indexed as

Analysis of VarianceBiomarkersComputational BiologyRegression AnalysisSample SizeBiomarkers

Identifiers

PMID29927942
PMCPMC6013185

What OpenQuestion holds

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Registered trials

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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.