Development and validation of a dynamic survival prediction model for patients with acute-on-chronic liver failure

Development and validation of a prediction model for in-hospital mortality in patients with sepsis

BACKGROUND

Sepsis, a life-threatening condition marked by organ dysfunction due to a dysregulated host response to infection, involves complex physiological and biochemical abnormalities.

AIM

To develop a multivariate model to predict 4-, 6-, and 8-week mortality risks in intensive care units (ICUs).

STUDY DESIGN

A retrospective cohort of 2389 sepsis patients was analysed using data captured by a clinical decision support system. Patients were randomly allocated into training (n = 1673) and validation (n = 716) sets at a 7:3 ratio. Least Absolute Shrinkage and Selection Operator (LASSO) regression identified variables incorporated into a multivariate Cox proportional hazards regression model to construct a prognostic nomogram. The area under the receiver operating characteristic curve (AUROC) assessed model accuracy, while performance was evaluated for discrimination, calibration and clinical utility.

RESULTS

A risk score was developed based on 11 independent predictors from 35 initial factors. Key predictors included minimum Acute Physiology and Chronic Health Evaluation II (APACHE II) score as having the greatest impact on prognosis, followed by days of mechanical ventilation, number of vasopressors, maximum and minimum Sequential Organ Failure Assessment (SOFA) scores, infection sources, Gram-positive or Gram-negative bacteria and malignancy. The nomogram demonstrated superior discriminative ability, with AUROC values of 0.882 (95% confidence interval [CI], 0.855-0.909) and 0.851 (95% CI, 0.804-0.899) at 4 weeks; 0.836 (95% CI, 0.798-0.874) and 0.820 (95% CI, 0.761-0.878) at 6 weeks; and 0.843 (95% CI, 0.800-0.887) and 0.794 (95% CI, 0.720-0.867) at 8 weeks for training and validation sets, respectively.

CONCLUSION

A validated nomogram and web-based calculator were developed to predict in-hospital mortality in ICU sepsis patients. Targeting identified risk factors may improve outcomes for critically ill patients.

RELEVANCE TO CLINICAL PRACTICE

The developed prediction model and nomogram offer a tool for assessing in-hospital mortality risk in ICU patients with sepsis, potentially aiding in nursing decisions and resource allocation.

Growing Evidence for Survival Benefit with Plasma Exchange to Treat Liver Failure

Plasma exchange (PLEX) to treat liver failure patients is gaining increasing momentum in recent years. Most reports have used PLEX to treat patients with acute liver failure (ALF) or acute on chronic liver failure (ACLF). Etiology of liver disease has an important bearing on the prognosis of the illness in these patients. The accruing data suggest survival benefit with PLEX compared with standard medical treatment to treat ALF and ACLF patients, in randomised controlled trials done world-over. The American College of Apheresis now recommends high-volume PLEX as first-line treatment for ALF patients. Most matched cohort studies done from India which recruited patients with a specific etiology of ALF or ACLF report survival benefit with PLEX compared to standard medical treatment. The survival benefit with PLEX appears more pronounced in ALF patients rather than in ACLF patients. Systematic analysis of the efficacy of PLEX to treat ALF and ACLF patients is needed. There is also a need to identify dynamic predictive scores to assess which patients with ALF or ACLF will respond to PLEX.

Liver Transplantation in Acute-on-Chronic Liver Failure

In recent years there has been a significant increase in the incidence of acute-on-chronic liver failure (ACLF). This syndrome is characterized by infections, organ failures, and high short-term mortality. Although progress in the management of these sick patients has been evident, liver transplantation (LT) remains the best treatment modality to date. Several studies have reported LT as a feasible option, despite organ failures. The outcomes following LT are inversely related to the grade of ACLF. This review discusses the current literature on the feasibility, futility, timing, and outcomes of LT in patients with ACLF.

External validation and longitudinal application of the DO-GAP index to individualise survival prediction in idiopathic pulmonary fibrosis

Background

The Distance-Oxygen-Gender-Age-Physiology (DO-GAP) index has been shown to improve prognostication in idiopathic pulmonary fibrosis (IPF) compared to the Gender-Age-Physiology (GAP) score. We sought to externally validate the DO-GAP index compared to the GAP index for baseline risk assessment in patients with IPF. Additionally, we evaluated the utility of serial change in the DO-GAP index in predicting survival.

Methods

We performed an analysis of patients with IPF from the Pulmonary Fibrosis Foundation-Patient Registry (PFF-PR). Discrimination and calibration of the two models were assessed to predict transplant-free survival and IPF-related mortality. Joint longitudinal time-to-event modelling was utilised to individualise survival prediction based on DO-GAP index trajectory.

Results

There were 516 patients with IPF from the PFF-PR with available demographics, pulmonary function tests, 6-min walk test data and outcomes included in this analysis. The DO-GAP index (C-statistic: 0.73) demonstrated improved discrimination in discerning transplant-free survival compared to the GAP index (C-statistic: 0.67). DO-GAP index calibration was adequate, and the model retained predictive accuracy to identify IPF-related mortality (C-statistic: 0.74). The DO-GAP index was similarly accurate in the subset of patients taking antifibrotic medications. Serial change in the DO-GAP index improved model discrimination (cross-validated area under the curve: 0.83) enabling the personalised prediction of disease trajectory in individual patients.

Conclusion

The DO-GAP index is a simple, validated, multidimensional score that accurately predicts transplant-free survival in patients with IPF and can be adapted longitudinally in individual patients. The DO-GAP may also find use in studies of IPF to risk stratify patients and possibly as a clinical trial end-point.