Age stratification improves pneumonia risk assessment
medwireNews: Age and residential status should be used to select the most appropriate measure to assess community-acquired pneumonia (CAP) severity in hospitalized patients, advise German researchers.
Hospitalized CAP patients aged 65 years or older who live at home should continue to be assessed using the CRB-65 clinical prediction rule, the currently favored tool in Europe, say Santiago Ewig (EVK Herne and Augusta-Kranken-Anstalt Bochum, Germany) and co-authors.
The CRB-65 scores severity according to the presence of new onset confusion (Abbreviated mental test score 8 or below), respiratory rate (30 breaths/minute or more), blood pressure (systolic <90 mmHg, diastolic <60 mmHg), and age over 65 years.
However, the team now recommends that patients aged less than 65 years should be assessed using an age cutoff of 50 years (CRB-50), while the best age cutoff for patients aged over 65 years who are residing in nursing homes is 80 years (CRB-80).
Patients with 0 points have a low risk for death (risk class [RC]1), those with 1-2 points an intermediate risk (RC2), and those with 3-4 points or who require ventilation at admission a high risk for death (RC3), they explain.
The team applied the CRB with different age cutoffs to data for 660,594 patients hospitalized in Germany between 2008 and 2010, 14.0% of whom died.
In the whole population, the CRB-80 performed best, with an area under the receiver operating characteristic (ROC) curve score of 0.690.
For patients aged less than 65 years, the CRB-50 had the highest area under the receiver operating characteristic (ROC) curve score, at 0.730. Just 1.28% of patients in RC1 died, rising to 5.68% of RC2, and 23.29% of RC3 patients, giving a negative predictive value of 98.7% for the CRB-50.
For patients older than 65 years living at home, the CRB-80 had the highest area under the ROC curve, at 0.663 versus 0.642 for CRB-65 but this difference is not expected to be clinically significant.
However, the researchers note that RC1 patients aged over 65 years were at significant risk, with a mortality rate of 6.62%, rising to 14.38% and 38.5% for RC2 and RC3 patients, respectively, using the CRB-80.
"This, of course, does not mean that any patient aged =65 years must be hospitalized but it may increase attention to individual risk factors that might support such treatment setting," the researchers caution.
Although the CRB-80 had the highest score for nursing home-acquired pneumonia (NHAP) patients aged 65 years and older, this was significantly lower than for the general population, at just 0.608.
And the score did not identify a group of patients at low risk in this population, with RC1, RC2, and RC3 patient mortality rates all considered high at 18.23, 32.08, and 48.91%, respectively.
The team therefore emphasizes: "NHAP patients need a different approach, and even if CRB-80 is used, initial risk assessment should be accompanied by the evaluation of functional status and comorbidity together with a consideration of treatment aims."
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By Lynda Williams, Senior medwireNews Reporter