Machine learning for fast identification of bacteraemia in SIRS patients treated on standard care wards: a cohort study

Sci Rep. 2018 Aug 15;8(1):12233. doi: 10.1038/s41598-018-30236-9.

Abstract

Bacteraemia is a life-threating condition requiring immediate diagnostic and therapeutic actions. Blood culture (BC) analyses often result in a low true positive result rate, indicating its improper usage. A predictive model might assist clinicians in deciding for whom to conduct or to avoid BC analysis in patients having a relevant bacteraemia risk. Predictive models were established by using linear and non-linear machine learning methods. To obtain proper data, a unique data set was collected prior to model estimation in a prospective cohort study, screening 3,370 standard care patients with suspected bacteraemia. Data from 466 patients fulfilling two or more systemic inflammatory response syndrome criteria (bacteraemia rate: 28.8%) were finally used. A 29 parameter panel of clinical data, cytokine expression levels and standard laboratory markers was used for model training. Model tuning was performed in a ten-fold cross validation and tuned models were validated in a test set (80:20 random split). The random forest strategy presented the best result in the test set validation (ROC-AUC: 0.729, 95%CI: 0.679-0.779). However, procalcitonin (PCT), as the best individual variable, yielded a similar ROC-AUC (0.729, 95%CI: 0.679-0.779). Thus, machine learning methods failed to improve the moderate diagnostic accuracy of PCT.

MeSH terms

  • Adult
  • Aged
  • Area Under Curve
  • Bacteremia / blood
  • Bacteremia / classification
  • Bacteremia / diagnosis*
  • Biomarkers / blood
  • Calcitonin / blood
  • Cohort Studies
  • Female
  • Forecasting
  • Humans
  • Machine Learning
  • Male
  • Middle Aged
  • Models, Theoretical
  • Prospective Studies
  • Protein Precursors / blood
  • ROC Curve
  • Systemic Inflammatory Response Syndrome / blood
  • Systemic Inflammatory Response Syndrome / complications*
  • Systemic Inflammatory Response Syndrome / microbiology

Substances

  • Biomarkers
  • Protein Precursors
  • Calcitonin