The effect of pneumonia on mortality among patients hospitalized for acute stroke.
OBJECTIVE
To determine the effect of pneumonia on 30-day mortality in patients hospitalized for acute stroke.


METHODS
Subjects in the initial cohort were 14,293 Medicare patients admitted for stroke to 29 greater Cleveland hospitals between 1991 and 1997. The relative risk (RR) of pneumonia for 30-day mortality was determined in a final cohort (n = 11,286) that excluded patients dying or having a do not resuscitate order within 3 days of admission. Clinical data were obtained from chart abstraction and were merged with Medicare Provider Analysis and Review files to obtain deaths within 30 days. A predicted-mortality model (c-statistic = 0.78) and propensity score for pneumonia (c-statistic = 0.83) were used for risk adjustment in logistic regression analyses.


RESULTS
Pneumonia was identified in 6.9% (n = 985) of all patients and in 5.6% (n = 635) of the final cohort. The rates of pneumonia were higher in patients with greater stroke severity and features indicating general frailty. Unadjusted 30-day mortality rates were six times higher for patients with pneumonia than for those without (26.9% vs 4.4%, p < 0.001). After adjusting for admission severity and propensity for pneumonia, RR of pneumonia for 30-day death was 2.99 (95% CI 2.44 to 3.66), and population attributable risk was 10.0%.


CONCLUSIONS
In this large community-wide study of stroke outcomes, pneumonia conferred a threefold increased risk of 30-day death, adding impetus to efforts to identify and reduce the risk of pneumonia in patients with stroke.
Katzan
I L
IL
Center for Health Care Research & Policy, Case Western Reserve University at MetroHealth Medical Center, Cleveland, OH 44109-1998, USA. ikatzan@metrohealth.org
Cebul
R D
RD
Husak
S H
SH
Dawson
N V
NV
Baker
D W
DW
D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D044383:Black People / Q000706:statistics & numerical data; D015331:Cohort Studies; D015897:Comorbidity; D004198:Disease Susceptibility / Q000453:epidemiology; D005260:Female; D016330:Frail Elderly / Q000706:statistics & numerical data; D017052:Hospital Mortality; D006801:Humans; D015994:Incidence; D007297:Inpatients / Q000706:statistics & numerical data*; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D009820:Ohio / Q000453:epidemiology; D011014:Pneumonia / Q000401:mortality*; D012306:Risk; D018570:Risk Assessment; D012720:Severity of Illness Index; D020521:Stroke / Q000401:mortality*; D044465:White People / Q000706:statistics & numerical data; D001741:Black or African American