Comparison of three models for sepsis patient discrimination according to PIRO: predisposition, infection, response and organ dysfunction.

BACKGROUND: Sepsis remains one of the most challenging burdens of critically ill patients. But for interventional studies significant heterogeneity remains in classifying patients. PIRO (Predisposition, Response, Infection and Organ dysfunction) has been introduced as innovative option for improved patient characterization. Aim of this study was to evaluate precision to predict hospital mortality of three different proposed PIRO classification systems.
METHODS: Data were prospectively obtained data in five ICUs in a university hospital in Berlin, Germany including adult patients with sepsis. Three different scoring systems were compared using patient characteristics to classify the population according to all cause hospital mortality risk (Moreno- PIRO, Rubulotta- PIRO and Howell-PIRO).
RESULTS: Two-hundred-seventy-eight sepsis patients were included and reclassified using different PIRO models. All cause hospital mortality was 16.2%. Hospital mortality increased with higher PIRO scores with odds ratios of 1.070 (95% CI 1.041-1.100) for Moreno-PIRO, 1.282 (95% CI 1.079-1.524) for Rubulotta-PIRO and 1.256 (95% CI 1.146-1.367) for Howell-PIRO. Area under the curves for Moreno-PIRO was 0.743 (95% CI: 0.687-0.793), for Rubulotta-PIRO 0.646 (95% CI: 0.587-0.702) and for Howell-PIRO 0.751 (95% CI: 0.696-0.801). Moreno-PIRO and Howell-PIRO were statistically different compared with Rubulotta-PIRO (P=0.046 and P=0.035).
CONCLUSION: Proposed PIRO classifications demonstrated slight differences between models without prioritization of one approach and all seemed feasible for patient classification. Future PIRO-development is needed to straighten predisposition, infection, and especially the response category.