Risk factors for mortality in patients admitted to intensive care units with pneumonia

Guowei Li; Deborah J Cook; Lehana Thabane; Jan O Friedrich; Tim M Crozier; John Muscedere; John Granton; Sangeeta Mehta; Steven C Reynolds; Renato D Lopes; Francois Lauzier; Andreas P Freitag; Mitchell A H Levine; PROTECT Investigators for the Canadian Critical Care Trials Group, and the Australian and New Zealand Intensive Care Society Clinical Trials Group

doi:10.1186/s12931-016-0397-5

Risk factors for mortality in patients admitted to intensive care units with pneumonia

Respir Res. 2016 Jul 11;17(1):80. doi: 10.1186/s12931-016-0397-5.

Authors

Guowei Li^{1

2}, Deborah J Cook^{3

4

5

6}, Lehana Thabane^{3

4}, Jan O Friedrich^{7

8}, Tim M Crozier⁹, John Muscedere¹⁰, John Granton^{7

11}, Sangeeta Mehta^{7

12}, Steven C Reynolds¹³, Renato D Lopes¹⁴, Francois Lauzier¹⁵, Andreas P Freitag⁵, Mitchell A H Levine^{16

17

18}; PROTECT Investigators for the Canadian Critical Care Trials Group, and the Australian and New Zealand Intensive Care Society Clinical Trials Group

Affiliations

¹ Department of Clinical Epidemiology & Biostatistics, McMaster University, 501-25 Charlton Avenue East, Hamilton, ON, L8N 1Y2, Canada. lig28@mcmaster.ca.
² St. Joseph's Healthcare Hamilton, McMaster University, 501-25 Charlton Avenue East, Hamilton, ON, L8N 1Y2, Canada. lig28@mcmaster.ca.
³ Department of Clinical Epidemiology & Biostatistics, McMaster University, 501-25 Charlton Avenue East, Hamilton, ON, L8N 1Y2, Canada.
⁴ St. Joseph's Healthcare Hamilton, McMaster University, 501-25 Charlton Avenue East, Hamilton, ON, L8N 1Y2, Canada.
⁵ Department of Medicine, McMaster University, Hamilton, ON, Canada.
⁶ Interdepartmental Division of Critical Care, Hamilton Health Sciences, Hamilton, ON, Canada.
⁷ Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada.
⁸ St. Michael's Hospital, University of Toronto, Toronto, ON, Canada.
⁹ Intensive Care Unit, Monash Medical Centre, Melbourne, VIC, Australia.
¹⁰ Department of Critical Care Medicine, Queens University Kingston, Kingston, ON, Canada.
¹¹ University Health Network, University of Toronto, Toronto, ON, Canada.
¹² Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada.
¹³ Division of Critical Care, Department of Medicine, University of British Columbia, Vancouver, BC, Canada.
¹⁴ Duke Clinical Research Institute, Duke University, Durham, NC, USA.
¹⁵ Department of Anesthesiology and Critical Care Medicine, Division of Critical Care Medicine, Université Laval, Québec, Canada.
¹⁶ Department of Medicine, McMaster University, Hamilton, ON, Canada. levinem@mcmaster.ca.
¹⁷ Department of Clinical Epidemiology & Biostatistics, McMaster University, 25 Main St. West, Suite 2000, 20th floor, Hamilton, ON, L8P 1H1, Canada. levinem@mcmaster.ca.
¹⁸ Centre for Evaluation of Medicines, St. Joseph's Healthcare Hamilton, 25 Main St. West, Suite 2000, 20th floor, Hamilton, ON, L8P 1H1, Canada. levinem@mcmaster.ca.

Abstract

Background: Despite the high mortality in patients with pneumonia admitted to an ICU, data on risk factors for death remain limited.

Methods: In this secondary analysis of PROTECT (Prophylaxis for Thromboembolism in Critical Care Trial), we focused on the patients admitted to ICU with a primary diagnosis of pneumonia. The primary outcome for this study was 90-day hospital mortality and the secondary outcome was 90-day ICU mortality. Cox regression model was conducted to examine the relationship between baseline and time-dependent variables and hospital and ICU mortality.

Results: Six hundred sixty seven patients admitted with pneumonia (43.8 % females) were included in our analysis, with a mean age of 60.7 years and mean APACHE II score of 21.3. During follow-up, 111 patients (16.6 %) died in ICU and in total, 149 (22.3 %) died in hospital. Multivariable analysis demonstrated significant independent risk factors for hospital mortality including male sex (hazard ratio (HR) = 1.5, 95 % confidence interval (CI): 1.1 - 2.2, p-value = 0.021), higher APACHE II score (HR = 1.2, 95 % CI: 1.1 - 1.4, p-value < 0.001 for per-5 point increase), chronic heart failure (HR = 2.9, 95 % CI: 1.6 - 5.4, p-value = 0.001), and dialysis (time-dependent effect: HR = 2.7, 95 % CI: 1.3 - 5.7, p-value = 0.008). Higher APACHE II score (HR = 1.2, 95 % CI: 1.1 - 1.4, p-value = 0.002 for per-5 point increase) and chronic heart failure (HR = 2.6, 95 % CI: 1.3 - 5.0, p-value = 0.004) were significantly related to risk of death in the ICU.

Conclusion: In this study using data from a multicenter thromboprophylaxis trial, we found that male sex, higher APACHE II score on admission, chronic heart failure, and dialysis were independently associated with risk of hospital mortality in patients admitted to ICU with pneumonia. While high illness severity score, presence of a serious comorbidity (heart failure) and need for an advanced life support (dialysis) are not unexpected risk factors of mortality, male sex might necessitate further exploration. More studies are warranted to clarify the effect of these risk factors on survival in critically ill patients admitted to ICU with pneumonia.

Trial registration: ClinicalTrials.gov Identifier: NCT00182143 .

Keywords: Intensive care; Mortality; Pneumonia; Risk factor.

Publication types

Multicenter Study
Randomized Controlled Trial
Research Support, Non-U.S. Gov't

MeSH terms

APACHE
Aged
Aged, 80 and over
Chi-Square Distribution
Databases, Factual
Female
Heart Failure / mortality
Hospital Mortality*
Humans
Intensive Care Units*
Kaplan-Meier Estimate
Kidney Diseases / mortality
Kidney Diseases / therapy
Male
Middle Aged
Multivariate Analysis
Patient Admission*
Pneumonia / diagnosis
Pneumonia / mortality*
Pneumonia / therapy
Proportional Hazards Models
Renal Dialysis / mortality
Risk Factors
Sex Factors
Time Factors

Associated data

ClinicalTrials.gov/NCT00182143

Grants and funding

MCT78568/CIHR/Canada