Inpatient Mortality Among Solid Organ Transplant Recipients Hospitalized for Sepsis and Severe Sepsis

Abstract

Background: Solid organ transplant (SOT) recipients are at elevated risk of sepsis. The impact of SOT on outcomes following sepsis is unclear.

Methods: We performed a retrospective cohort study using data from University HealthSystem Consortium, a consortium of academic medical center affiliates. We examined the association between SOT and mortality among patients hospitalized with severe sepsis or explicitly coded sepsis in 2012-2014. We used International Classification of Diseases, Ninth Revision (ICD-9) codes to identify severe sepsis, explicitly coded sepsis, and SOT (kidney, liver, heart, lung, pancreas, or intestine transplants). We fit random-intercept logistic regression models to account for clustering by hospital.

Results: There were 903 816 severe sepsis hospitalizations (39 618 [4.4%] with SOT) and 410 623 sepsis hospitalizations (14 526 [3.9%] with SOT) in 250 hospitals. SOT recipients were younger and more likely to be insured by Medicare than those without SOT. Among hospitalizations for severe sepsis and sepsis, in-hospital mortality was lower among those with vs those without SOT (5.5% vs 9.4% for severe sepsis; 8.7% vs 12.7% for sepsis). After adjustment, the odds ratio for mortality comparing SOT patients vs non-SOT was 0.83 (95% confidence interval [CI], .79-.87) for severe sepsis and 0.78 (95% CI, .73-.84) for sepsis. Compared to non-SOT patients, kidney, liver, and co-transplant (kidney-pancreas/kidney-liver) recipients demonstrated lower mortality. No association was present for heart transplant, and lung transplant was associated with higher mortality.

Conclusions: Among patients hospitalized for severe sepsis or sepsis, those with SOT had lower inpatient mortality than those without SOT. Identifying the specific strategies employed for populations with improved mortality could inform best practices for sepsis among SOT and non-SOT populations.

Keywords: critical care; infection; outcomes; sepsis; transplant.

Figure 1.

University HealthSystem Consortium study population flowchart, 2012–2014. Severe sepsis defined using the Angus criteria (International Classification of Diseases, Ninth Revision [ICD-9] codes for infection and organ dysfunction), while sepsis was defined as any hospitalization with an explicit ICD-9 code for sepsis (995.91), severe sepsis (995.92), or septic shock (785.52). All definitions required that ICD-9 codes were present at the time of admission. Severe sepsis and explicit sepsis are not mutually exclusive definitions; cases can belong to both groups. All percentages relative to category above. Abbreviations: Co-Tx, kidney-pancreas or kidney-liver co-transplant; Other, pancreas-only transplant or intestine transplant; SOT, solid organ transplant.

Figure 2.

Odds ratios for inpatient mortality among severe sepsis and sepsis hospitalizations, 2012–2014. A, Primary analysis of the association between solid organ transplant (SOT) and inpatient mortality among severe sepsis and sepsis hospitalizations. B, Sensitivity analyses of the association between SOT and inpatient mortality among select subgroups of severe sepsis hospitalizations. Severe sepsis was defined using the Angus criteria (International Classification of Diseases, Ninth Revision [ICD-9] codes for infection and organ dysfunction), while sepsis was defined as any hospitalization with an explicit ICD-9 code for sepsis (995.91), severe sepsis (995.92), or septic shock (785.52). All definitions required that ICD-9 codes were present at the time of admission. Healthcare-associated severe sepsis was defined as any case that was admitted from a skilled nursing facility or home health, was on dialysis, or represented a readmission within 30 days of a prior discharge from the same institution. All models adjusted for age, sex, race, insurance type, intensive care unit (ICU) admission, discharge physician specialty (internal medicine vs not), All Patient Refined risk of mortality, and Elixhauser comorbidities. Odds ratios (ORs) were estimated using random-intercept logistic regression. Abbreviations: CI, confidence interval; Co-Tx, kidney-pancreas or kidney-liver co-transplant.