Impact of the National Early Warning Score-based sepsis response system on hospital-onset sepsis in a tertiary hospital in South Korea

Abstract

Background: The effectiveness of electronic medical record-based alert systems, response protocols for sepsis diagnosis, and treatment in hospitalized patients remains unclear. This study aimed to determine whether the introduction of an electronic medical record-based sepsis response protocol (SRP) along with a 24/7 operating rapid response system affects the prognosis for patients with hospital-onset sepsis.

Methods: In August 2022, a SRP based on the National Early Warning Score was implemented in the electronic medical record system at Asan Medical Center. We retrospectively analyzed patients screened by the detection system for 1 year after the SRP implementation. Patients of the first 6 months (preliminary group) and those of the second 6 months (SRP group) were matched 1:1 based on propensity scores. The primary outcome was 30-day mortality.

Results: Of the 608 hospitalized patients screened by the system, 176 were assigned to each group after 1:1 propensity score matching. Patients in the SRP group were significantly more likely to receive blood cultures (58.5%) compared with the preliminary group (45.5%) (P=0.019). The SRP group showed a lower 30-day mortality risk (hazard ratio, 0.56; 95% CI, 0.36-0.86; P=0.017) compared to the preliminary group. A restricted cubic spline curve showed that SRP survival benefit began to manifest after the first 4 months (P=0.036).

Conclusions: Alongside an existing rapid response system, the National Early Warning Score-based SRP in the electronic medical record reduced mortality for hospital-onset sepsis within 1 year.

Keywords: early diagnosis; electronic health records; hospital rapid response team.

Figure 1.

Workflow of the National Early Warning Score (NEWS)-based electronic medical record (EMR) system and Sepsis Response Protocol for early diagnosis of sepsis. RED: Rapid response, Emergency assessment, and Decision for escalation and ongoing monitoring; EKG: electrocardiogram; SpO₂: saturation of peripheral oxygen.

Figure 2.

Flowchart of analyzed patient cohorts. ICU: intensive care unit; SRP: sepsis response protocol.

Figure 3.

Histogram showing the intervals for each sepsis bundle component from time zero to completion. (A) Preliminary group. (B) Sepsis response protocol (SRP) group. The bars are spaced at 60-minute intervals.

Figure 4.

Kaplan-Meier estimates of cumulative probabilities of 28-day survival in the propensity score matched cohort. SRP: sepsis response protocol; HR: hazard ratio.

Figure 5.

The association between the timing of system implementation and hospital mortality. A restricted cubic spline model showing the hazard ratio for hospital deaths based on the number of days since the system’s implementation, adjusted for National Early Warning Score. The model included three knots at the 10th, 50th, and 90th percentiles of the days (with the 10th percentile as the reference). Solid lines stand for hazard ratios (HRs), shaded areas show 95% CIs, and dotted lines represent the knots.

Figure 6.

Association between the timing of prescription or completion of each bundle component and hospital mortality. The restricted cubic spline model shows the hazard ratio (HR) for hospital deaths based on the time after prescription or completion of bundle component. The model was conducted with three knots at the 10th, 50th, and 90th day percentiles. Reference is the 10th percentile in panels (A) and (B), the 50th percentile in panel (F), and the 90th percentile in panels (C), (D), and (E). Solid lines indicate the hazard ratios, shadowed shapes show 95% CIs, and dotted lines represent the knots.