University of Pittsburgh Researchers Uncover Four Phenotypes of Sepsis

Discovery follows study of nearly 64,000 EHRs

Using intricate computer algorithms, University of Pittsburgh (UPMC) researchers mined the electronic health records (EHRs) of almost 64,000 patients to derive four phenotypes of sepsis, marked by demographics, lab values, and outcomes.

More research is needed to make conclusions on each type of sepsis, but the investigators also suggested that their findings might lead to better treatment for this life-threatening condition.

“Hopefully, by seeing sepsis as several distinct conditions with varying clinical characteristics, we can discover and test therapies precisely tailored to the type of sepsis each patient has,” said first author Christopher Seymour, MD, MSc, an associate professor of medicine at UPMC.

Based on statistical machine learning and simulation tools, the algorithms analyzed 29 clinical variables in patient EHRs to identify the four phenotypes:

  • Alpha: The most common type (33%), with the fewest abnormal lab values, least organ dysfunction, and lowest in-hospital death rate (2%);
  • Beta: Patients in this type (27%) were typically older and had the most chronic illnesses and kidney dysfunction;
  • Gamma: These patients (27%) had elevated measures of inflammation, mostly pulmonary dysfunction, and the second-highest in-hospital death rate (15%);
  • Delta: These patients (13%) typically were the sickest, often with liver dysfunction and shock. 85% were admitted to intensive care, and 32% died in hospital.

The authors developed and validated the algorithm and their findings in three patient groups and assessed reproducibility, correlation with biological parameters, and clinical outcomes in one patient group and in other recently completed international clinical trials involving sepsis care. The patient groups included 20,000 UPMC patients recognized to have sepsis within six hours of hospital arrival between 2010-2012, 43,000 UPMC sepsis patients from 2013-2014, and 583 patients at 28 U.S. hospitals who developed sepsis due to pneumonia.


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