Impact of Infection Patterns on the Outcomes of Patients with Hematological Malignancies in Southwest China: A 10-Year Retrospective Case-Control Study

Abstract

Background: This study aimed to assess the effect of infection patterns on the outcomes of patients with hematological malignancies (HM) and to identify the determinants of in-hospital mortality.

Methods: A case-control study was retrospectively conducted in a tertiary teaching hospital in Chongqing, Southwest China from 2011 to 2020. Clinical characteristics, microbial findings, and outcomes of HM patients with infections were retrieved from the hospital information system. Chi-square or Fisher's exact test was adopted to test the significance of mortality rate. Kaplan-Meier survival analysis and Log rank test were applied to evaluate and compare the 30-day survival rates of those groups. Binary logistic regression, Cox proportional hazards regression, and receiver operating characteristic curves were used to investigate the determinants of in-hospital mortality.

Results: Of 1,570 enrolled participants, 43.63% suffered from acute myeloid leukemia, 69.62% received chemotherapy, and 25.73% had hematopoietic stem cell transplantation (HSCT). Microbial infection was documented in 83.38% of participants. Co-infection and septic shock were reported in 32.87% and 5.67% of participants, respectively. Patients with septic shock suffered a significantly lower 30-day survival rate, while those with distinct types of pathogens or co-infections had a comparable 30-day survival rate. The all-cause in-hospital mortality was 7.01% and higher mortality rate was observed in patients with allo-HSCT (7.20%), co-infection (9.88%), and septic shock (33.71%). Cox proportional hazards regression illustrated that elderly age, septic shock, and elevated procalcitonin (PCT) were independent predictors of in-hospital mortality. A PCT cut-off value of 0.24 ng/mL predicted in-hospital mortality with a sensitivity of 77.45% and a specificity of 59.80% (95% CI = 0.684-0.779, P<0.0001).

Conclusion: Distinct infectious patterns of HM inpatients were previously unreported in Southwest China. It was the severity of infection, not co-infection, source of infection, or type of causative pathogen that positively related to poor outcome. PCT guided early recognition and treatment of septic shock were advocated.

Keywords: determinants; early survival; hematological malignancies; in-hospital mortality; microbial co-infection; septic shock.

Figure 1

Flowchart of the enrollment of HM inpatients in this study.

Figure 2

The infection profiles of HM inpatients. Distribution of (A) microbial, (B) top three causative pathogens isolated from distinct sources of infections (C) infections by distinct quantities of causative pathogens.

Figure 3

Survival curves by (A) hematological malignancies, (B) treatments, (C) quantity of causative pathogens, and (D) severity of infection. Differences between these groups were assessed by using Log rank test and Wilcoxon test.

Figure 4

The in-hospital mortality of HM inpatients with distinct (A) types of malignancy, (B) treatments, (C) source of infection, (D) microbial, (E) quantities of microbial, and (F) severity of infection. Differences between the groups were assessed using Chi-square or Fisher’s exact test. Asterisks indicate statistical significance as P-values were less than *0.05, **0.01 or ***0.001.

Figure 5

(A) Cox regression analysis of predictors of in-hospital mortality and (B) ROC curves of PCT for predicting in-hospital mortality. (A) predictors of in-hospital mortality with red color indicate statistical significance.