Outcomes of Patients with Chronic Lymphocytic Leukemia Admitted with Sepsis: An Analysis of National Inpatient Sample Database
Authors: Lingamaneni Prasanth , Farooq Muhammad Zain , Vohra Ishaan , Upadhyay Shristi , Malapati Sindhu , Singh Sunny R K 
Published: November 2019

Background: Chronic lymphocytic leukemia (CLL) has a very high prevalence in the Western hemisphere, secondary to increased life expectancy and improved therapeutic options. Infections are known to be the prime contributor to morbidity and mortality in this patient population, accounting for 50-60% of all deaths. This occurs secondary to humoral depression by the disease and immune suppression by the treatment. There is paucity of data regarding outcomes of sepsis in CLL patients. We aim to study in-hospital outcomes of sepsis in patients with CLL.

Methods: This is a retrospective cohort analysis of National inpatient sample (NIS) database (year 2016). Patients with CLL who were admitted with a principal diagnosis of sepsis were identified using the associated ICD-10 codes. Admissions were further categorized based on remission status of CLL: group 1 was in remission, group 2 had not achieved remission and group 3 had relapse. Primary outcome was inpatient mortality and secondary outcome was the use of mechanical ventilation (as a surrogate for utilization of intensive care). Comparisons were made between the subgroups of CLL as listed above and non-CLL patients. Associated factors were analyzed using multivariable regression model. We used STATA for statistical analysis.

Results: Among patients with CLL who were admitted, the most common principal diagnosis (reason for admission) was sepsis, accounting for 12.9% of all CLL admissions. Other common reasons for admissions were pneumonia (5.4%), acute kidney injury (2.3%), NSTEMI (1.8%) and COPD exacerbation (1.8%). A total of 9,315 admissions with sepsis in CLL patients were identified (780 in remission, 8280 had not achieved remission and 255 had relapse). Compared to non-CLL patients, CLL patients were older (mean age 75.1 vs 64.7, p=0.0001), had more males (62.3% vs 49.3%, p=0.00001) and higher percentage of Caucasians (81.8% vs 67.5%, p=0.00001). CLL patients had higher inpatient mortality (14% vs 10%, p=0.00001), longer length of stay (7.8 vs 7.3 days, p=0.003) and higher hospital charges ($83,000 vs $75,000, p=0.006).

On multivariable logistic regression model, after adjusting for age, gender, race and number of comorbidities, CLL patients were comparable with non-CLL patients, in regard to mortality and mechanical ventilation.

On analysis of subgroups of CLL, those with CLL in remission had lower mortality (OR 0.51, CI 0.28-0.91, p=0.024) when compared to non-CLL patients. Group 2 (CLL, not yet achieved remission) were not statistically significant, whereas, group 3 (CLL in relapse) had higher mortality (OR 2.97, CI 1.64-5.35, p=0.000). Only group 3 CLL patients had higher risk of requiring mechanical ventilation (OR 2.92, CI 1.52-5.61, p=0.001).

Conclusions: Infectious complications continue to remain a major cause of mortality and morbidity in CLL. Sepsis constituted the most common principal diagnosis in CLL patients admitted to acute-care hospitals. CLL patients with sepsis had higher mortality, compared to their non-CLL counterparts, even after adjusting for age, gender and other variables. Patients with relapsed disease had higher inpatient mortality when admitted to sepsis and interestingly, those with CLL in remission had lower mortality when compared to non-CLL patients.

Disclosures

No relevant conflicts of interest to declare.