The prevalence of anemia and its association with 90-day mortality in hospitalized community-acquired pneumonia.
BACKGROUND
The prevalence of anemia in the intensive care unit is well-described. Less is known, however, of the prevalence of anemia in hospitalized patients with lesser illness severity or without organ dysfunction. Community-acquired pneumonia (CAP) is one of the most frequent reasons for hospitalization in the United States (US), affecting both healthy patients and those with comorbid illness, and is typically not associated with acute blood loss. Our objective was to examine the development and progression of anemia and its association with 90d mortality in 1893 subjects with CAP presenting to the emergency departments of 28 US academic and community hospitals.


METHODS
We utilized hemoglobin values obtained for clinical purposes, classifying subjects into categories consisting of no anemia (hemoglobin >13 g/dL), at least borderline (<or= 13 g/dL), at least mild (<or= 12 g/dL), at least moderate (<or= 10 g/dL), and severe (<or= 8 g/dL) anemia. We stratified our results by gender, comorbidity, ICU admission, and development of severe sepsis. We used multivariable logistic regression to determine factors independently associated with the development of moderate to severe anemia and to examine the relationship between anemia and 90d mortality.


RESULTS
A total of 8240 daily hemoglobin values were measured in 1893 subjects. Mean (SD) number of hemoglobin values per patient was 4.4 (4.0). One in three subjects (33.9%) had at least mild anemia at presentation, 3 in 5 (62.1%) were anemic at some point during their hospital stay, and 1 in 2 (54.5%) survivors were discharged from the hospital anemic. Anemia increased with illness severity and was more common in those with comorbid illnesses, female gender, and poor outcomes. Yet, even among men and in those with no comorbidity or only mild illness, anemia during hospitalization was common (approximately 55% of subjects). When anemia was moderate to severe (<or= 10 g/dL), its development was independently associated with increased 90d mortality, even among hospital survivors.


CONCLUSIONS
Anemia was common in hospitalized CAP and independently associated with 90d mortality when hemoglobin values were 10 g/dL or less. Whether prevention or treatment of CAP-associated anemia would improve clinical outcomes remains to be seen.
The CRISMA Clinical Research, Investigation, and Systems Modeling of Acute Illness Laboratory, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
Michael C
MC
Reade
Lisa
L
Weissfeld
Derek C
DC
Angus
John A
JA
Kellum
Eric B
EB
Milbrandt
D000368:Aged; D000369:Aged, 80 and over; D000740:Anemia / Q000097:blood / Q000401:mortality*; D017714:Community-Acquired Infections / Q000401:mortality*; D015897:Comorbidity; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D017052:Hospital Mortality; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000401:mortality*; D015995:Prevalence; D012307:Risk Factors; D012720:Severity of Illness Index; D014481:United States / Q000453:epidemiology
D006454:Hemoglobins