Clinical validation demonstrates concordance of qSOFA and POC lactate Bayesian model: Results from the ACDC Phase-2 program

Abstract

Sepsis is a common and lethal medical problem. The objective of this study was to validate a Bayesian Model that integrates qSOFA and prehospital Lactate, with a comparison analysis from a real clinical data of patients with sepsis.

Methods: We conducted a two tired validation study with one arm focusing on Bayesian modeling and a second retrospective observational arm addressing real data validation. For Bayesian modeling, sensitivity and specificity of prehospital lactate were attained from pooled meta-analysis data. Later, for clinical validation, we used data from 2016 to 2017 of ED patients diagnosed with sepsis. Pretest probabilities from qSOFA score where combined with prehospital lactate and inserted into a Bayesian model to calculate posttest probabilities. Absolute and relative diagnostic gains were calculated. Statistical significance was assessed via t-test, chi square and odds ratio. P value was set to be 0.05.

Results: For the Bayesian arm; meta-analysis data for prehospital lactate resulted in a positive likelihood ratio (LR+) of 1.69 and negative likelihood ratio (LR-) of 0.44. Integration of lactate and qSOFA demonstrated significant post-test improvements. On the Clinical Validation arm, 1470 patients were included with 176 patients meeting analysis criteria. When comparing qSOFA + Abnormal Lactate vs qSOFA and normal Lactate, the ICU vs Non-ICU cohorts were statistically different (p < 0.01) Odds Ratio: 2.35 (95% CI [1.22-4.6]).

Conclusion: Bayesian mathematical model demonstrated that a qSOFA-based clinical decision can be complemented by the use of point of-care lactate. These results were confirmed by our clinical validation arm.