Development and external validation of a new clinical prediction model for early recognition of sepsis in adult patients in primary care: a diagnostic study

Abstract

Background: Recognising patients who need immediate hospital treatment for sepsis while simultaneously limiting unnecessary referrals is challenging for GPs. Aim: Develop and validate a sepsis prediction model for adult patients in primary care. Design and setting: Prospective cohort study in four out-of-hours primary care services in the Netherlands, between June 2018 and March 2020. Method: Acutely ill adult patients who received home visits were included. Nine clinical variables were candidate predictors, next to the biomarkers C-reactive protein, procalcitonin, and lactate. The primary endpoint was sepsis within 72 hours of inclusion, as established by an expert panel. Multivariable logistic regression with backwards selection was used to design an optimal model with continuous clinical variables. The added value of the biomarkers was evaluated. Subsequently, a simple model using single cutoff points of continuous variables was developed and externally validated in two emergency department populations. Results: 357 patients were included with a median age of 80 years, of which 151 (42%) were diagnosed with sepsis. A model based on a simple count of one point for each of six variables (age>65 years; temperature>38°C; systolic blood pressure≤110 mmHg; heart rate>110/min; saturation≤95%; altered mental status) had good discrimination and calibration (C statistic of 0.80 [95% CI 0.75-0.84]; Brier score 0.175). Biomarkers did not improve the performance of the model and were therefore not included. The model was robust during external validation. Conclusion: Based on this GP out-of-ours population, a simple model can accurately predict sepsis in acutely ill adult patients using readily available clinical parameters.

Potential impact of a new sepsis prediction model for the primary care setting: early health economic evaluation using an observational cohort

“…All patients (or their legal representatives in case of mental incapacitation) provided informed consent. Other details of the methods of this study were published previously 15. Candidate predictors for the decision model were collected prospectively by the GPs who included the patients.…”

“…We performed the analyses using data of a cohort of 357 patients included in a previously described observational diagnostic study. 15 16 As the clinical effect of using the prediction model is not studied yet, these data were used as input for a decision tree to perform an early economic evaluation. The analyses were performed from a third-party payer/healthcare perspective with a time horizon of 1 month.…”

“…Other details of the methods of this study were published previously. 15 Candidate predictors for the decision model were collected prospectively by the GPs who included the patients. Sepsis diagnosis and need for hospital assessment of patients (regardless of the final diagnosis) were judged by three expert panels.…”

“…Recognition of sepsis can potentially be improved by a clinical prediction model consisting of vital signs and other readily available clinical information. Our research group recently showed a simple diagnostic sepsis model enables general practitioners (GPs) to estimate the risk of sepsis in adult patients immediately at the bedside 15. Ideally, all patients with sepsis are referred to the hospital after GP assessment.…”

“…Our research group recently showed a simple diagnostic sepsis model enables general practitioners (GPs) to estimate the risk of sepsis in adult patients immediately at the bedside. 15 Ideally, all patients with sepsis are referred to the hospital after GP assessment. However, such a strategy aiming not to miss cases of sepsis will also lead to more unnecessary hospital referrals and can potentially increase medical costs.…”