Clinical Subtypes of Sepsis Survivors Predict Readmission and Mortality after Hospital Discharge

Abstract

Rationale: Sepsis survivors experience adverse outcomes including high rates of postdischarge mortality and rehospitalization. Given the heterogeneity of the condition, using a person-centered framework to identify subtypes within this population with different risks of postdischarge outcomes may optimize postsepsis care. Objectives: To classify individuals into subtypes and assess the association of subtypes with 30-day rehospitalization and mortality. Methods: We conducted a retrospective observational study between January 2014 and October 2017 among 20,745 patients admitted to one of 12 southeastern U.S. hospitals with a clinical definition of sepsis. We used latent class analysis to classify sepsis survivors into subtypes, which were evaluated against 30-day readmission and mortality rates using a specialized regression approach. A secondary analysis evaluated subtypes against readmission rate for ambulatory care-sensitive conditions. Results: Among 20,745 patients, latent class analysis identified five distinct subtypes as the optimal solution. Clinical subtype was associated with 30-day readmission, with the subtype existing poor health with severe illness and complex needs after discharge demonstrating highest risk (35%) and the subtype low risk, barriers to care demonstrating the lowest risk (9%). Forty-seven percent of readmissions in the subtype poor functional status were for ambulatory care-sensitive conditions, whereas 17% of readmissions in the subtype previously healthy with severe illness and complex needs after discharge, barriers to care were for ambulatory care-sensitive conditions. Subtype was significantly associated with 30-day mortality: highest in for existing poor health with severe illness and complex needs after discharge (8%) and lowest for low risk, barriers to care (0.1%). Conclusions: Sepsis survivors can be classified into subtypes representing nuanced constellations of characteristics, with differential 30-day mortality and readmission risk profiles. Predischarge classification may allow an individualized approach to postsepsis care.

Keywords: hospital readmission; mortality; phenotype; sepsis; survivor.

Figure 1.

Conceptual domains and key indicators for developing sepsis survivor latent phenotypes.

Figure 2.

Heatmap displaying the standardized mean values for each variable across groups. The heatmap is shaded according to the proportion of each indicator in the five latent classes. Values represent a relative increase (red) or decrease (blue) from the mean of the proportion in the overall cohort, with darker gradients depicting larger relative differences (i.e., up to ±1 standard deviation from the mean). ADI = Area Deprivation Index; CCI = Charlson Comorbidity Index; D/C = discharge; SE = standard error.

Figure 3.

(A and B) Comparison of 30-day hospital readmission (A) and mortality outcomes (B) for five-class model. P < 0.01 for all pairwise comparisons unless otherwise indicated. *P = 0.29, **P = 0.99, and ***P = 0.19 for paired comparisons.