A
PREDICTION RULE TO IDENTIFY LOW-RISK PATIENTS WITH COMMUNITY-ACQUIRED
PNEUMONIA.
Fine
MJ, et al. N Engl J Med 1997 Jan 23;336(4):243-50.
BACKGROUND:
There is considerable variability in rates of hospitalization of patients with
community-acquired pneumonia, in part because of physicians' uncertainty in
assessing the severity of illness at presentation.
METHODS:
From our analysis of data on 14,199 adult inpatients with community-acquired
pneumonia, we derived a prediction rule that stratifies patients into five
classes with respect to the risk of death within 30 days. The rule was
validated with 1991 data on 38,039 inpatients and with data on 2287 inpatients
and outpatients in the Pneumonia Patient Outcomes Research Team (PORT) cohort
study. The prediction rule assigns points based on age and the presence of
coexisting disease, abnormal physical findings (such as a respiratory rate of
> or = 30 or a temperature of > or = 40 degrees C), and abnormal
laboratory findings (such as a pH <7.35, a blood urea nitrogen concentration
> or = 30 mg per deciliter [11 mmol per liter] or a sodium concentration
<130 mmol per liter) at presentation.
RESULTS:
There were no significant differences in mortality in each of the five risk
classes among the three cohorts. Mortality ranged from 0.1 to 0.4 percent for
class I patients (P=0.22), from 0.6 to 0.7 percent for class II (P=0.67), and
from 0.9 to 2.8 percent for class III (P=0.12). Among the 1575 patients in the
three lowest risk classes in the Pneumonia PORT cohort, there were only seven
deaths, of which only four were pneumonia-related. The risk class was
significantly associated with the risk of subsequent hospitalization among
those treated as outpatients and with the use of intensive care and the number
of days in the hospital among inpatients.
CONCLUSIONS:
The prediction rule we describe accurately identifies the patients with
community-acquired pneumonia who are at low risk for death and other adverse
outcomes. This prediction rule may help physicians make more rational decisions
about hospitalization for patients with pneumonia.
COMMENTS:
Independent predictors of increased mprtality included age > 50, coexisting
illnesses (CHF, neoplastic, cerebrovascular, renal or liver disease), and
abnormal physical findings (AMS, HR > 125, RR > 30, SBP < 90mm Hg, and
T < 35ēC or > 40ēC). Additional risk factors identified included male
sex, nursing home residence, and abnormal laboratory or radiographic findings
(BUN > 30mg/dl, gluc > 250mg/dL, Hct < 30%, Na < 130mmol/L, PaO2 <
60mm Hg, pH < 7.35, and pleural effusion). These findings still require
confirmation.