For the 81 molecules considered, difference between median values of alveolar and environmental air, with values standardized to environmental air.

<p>For the 81 molecules considered, difference between median values of alveolar and environmental air, with values standardized to environmental air.</p

Variables and coefficients of the logistic regression model with outcome variables: Patients with inflammatory bowel disease vs. controls (surgical + gastroenterological).

<p>Variables and coefficients of the logistic regression model with outcome variables: Patients with inflammatory bowel disease vs. controls (surgical + gastroenterological).</p

Performance of model comparing Crohn’s disease patients to ulcerative colitis patients (in parenthesis, the number of correctly classified cases).

<p>Performance of model comparing Crohn’s disease patients to ulcerative colitis patients (in parenthesis, the number of correctly classified cases).</p

For the 81 molecules considered, VOCs profiles of median values of CD and UC patients compared to control subjects, with values standardized to the median values of control subjects.

<p>For the 81 molecules considered, VOCs profiles of median values of CD and UC patients compared to control subjects, with values standardized to the median values of control subjects.</p

Description of the sample of inflammatory bowel disease cases and controls enrolled in the study (children 10 to 17 years of age).

<p>Description of the sample of inflammatory bowel disease cases and controls enrolled in the study (children 10 to 17 years of age).</p

Measured (the first 9 in the table) or hypothesized (the others)^* VOCs that emerged as significant in our models^**.

<p>Measured (the first 9 in the table) or hypothesized (the others)^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0184118#t014fn001" target="_blank">*</a>} VOCs that emerged as significant in our models^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0184118#t014fn002" target="_blank">**</a>}.</p

Diagnoses of the gastroenterological controls according to their classification in the model IBD vs. controls.

<p>Diagnoses of the gastroenterological controls according to their classification in the model IBD vs. controls.</p

Performance of the model with calibrated VOCs comparing patients with inflammatory bowel disease vs. controls (surgical and gastroenterological), for sensitivity levels above 90% (in parenthesis, the correctly classified).

<p>Performance of the model with calibrated VOCs comparing patients with inflammatory bowel disease vs. controls (surgical and gastroenterological), for sensitivity levels above 90% (in parenthesis, the correctly classified).</p

Performance of model comparing patients with inflammatory bowel disease vs. gastroenterological controls, for sensitivity levels above 90% (in parenthesis, the correctly classified).

<p>Performance of model comparing patients with inflammatory bowel disease vs. gastroenterological controls, for sensitivity levels above 90% (in parenthesis, the correctly classified).</p

Variables and coefficients of the logistic regression model built with directly or indirectly calibrated VOCs, with outcome variable: Patients with inflammatory bowel disease vs. controls (surgical and gastroenterological).

<p>Variables and coefficients of the logistic regression model built with directly or indirectly calibrated VOCs, with outcome variable: Patients with inflammatory bowel disease vs. controls (surgical and gastroenterological).</p