Variables associated with antibiotic prescribing in univariate logistic regression.

<p>Variables associated with antibiotic prescribing in univariate logistic regression.</p

Patients` characteristics.

<p>Patients` characteristics.</p

Associations of laboratory and clinical factors with antibiotic prescribing.

<p>Odds ratio estimates with 95% confidence intervals (95%CI) from univariate and multivariate logistic regression analysis. Open circles and dashed lines: univariate OR and 95%CI; variables are presented in decreasing order of strength of association with antibiotic prescription (p-value, details: see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0185197#pone.0185197.t002" target="_blank">Table 2</a>), grey circles indicate a non-significant association (p-value ≥ 0.05), the OR estimate for pleural rub (OR>>10 with 95%CI ranging from 0-infinity, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0185197#pone.0185197.t001" target="_blank">Table 1</a>) is not illustrated. Black dots and solid lines: multivariate OR with 95%CI of variables remaining after backward deletion of non-significant variables. Vertical line: OR = 1 indicating no association with antibiotic prescription, ORs > 1 indicate an association with increased antibiotic prescription, ORs < 1 indicate an association with reduced antibiotic use. CRP: C-reactive protein. WBC: White blood cell count. Vacc.: Vaccine. RSV: Respiratory syncytial virus. HR: Heart rate. Hib: <i>Haemophilus influenzae</i> type b.</p

Sensitivities and specificities for associations with antibiotic prescribing.

<p>Illustration of sensitivities and specificities (dots) with 95% confidence intervals (crosses) of each single variable for antibiotic prescription. Left panel: dichotomous variables. Right panel: For continuous variables the range of sensitivities and specificities for all possible thresholds is illustrated (gray receiver operating characteristic curves), as well as the sensitivity and specificity associated with the best threshold estimates. Best threshold estimates (95%CI) were: CRP: 26 (12–55) mg/L, age: 2.1 (1.1–4.8) years, temperature: 38.6 (37.3–38.9) °C, preceding fever: 2.5 (1.5–5.5) days. CRP: C-reactive protein. RSV: Respiratory syncytial virus. WBC: White blood cell count.</p

Variables associated with antibiotic prescription in multivariate logistic regression.

<p>Variables associated with antibiotic prescription in multivariate logistic regression.</p

Duration of antibiotic treatment.

<p>Box plots of the distribution of the duration of antibiotic (AB) treatment (in days) for children and adolescents with lower respiratory tract infection (LRTI) in the procalcitonin (PCT) and control group.</p

Trial profile.

<p>Trial profile.</p

Impairment of daily activities.

<p>Impairment of daily activities attributable to lower respiratory tract infection (LRTI) over time in 267 children and adolescents who returned diaries in the procalcitonin (PCT) and control group. The smooth curves are local averages calculated using the default loess smoother in R.</p

Patient baseline characteristics.

<p>Abbreviations: PCT, procalcitonin; IQR, interquartile range; CRP, C-reactive protein; Non-CAP, non-community-acquired pneumonia; LRTI, lower respiratory tract infection. * N in this column indicate the number of individuals with information on a particular variable.</p

Subgroup analyses.

<p>Abbreviations: PCT, procalcitonin; CI, confidence interval; Non-CAP, non-community-acquired pneumonia; LRTI, lower respiratory tract infection. * Number of individuals with available data for a given endpoint.</p