Risk factors shown to be independent in multivariate analysis:
(1) need for mechanical ventilation
(2) abnormal chest X-ray on admission
(3) dysphagia
|
Risk Factor
|
Odds Ratio
|
95% CI
|
p value
|
|
mechanical ventilation
|
35.7
|
6.5 to 194.7
|
< 0.001
|
|
abnormal chest X-ray
|
7.3
|
1.8 to 29.2
|
0.005
|
|
dysphagia
|
3.3
|
0.9 to 11.7
|
0.064
|
where:
• The p value for dysphagia is not < 0.05.
• An abnormal chest X-ray on admission may indicate that (1) the person aspirated, (2) the person was in heart failure, (3) the person already had a respiratory infection.
• Most of the risk appears to be ventilator-associated or aspiration-related.
Additional risk factors identified on univariate analysis:
(1) vertebrobasilar stroke
(2) more than 1 infarcted vascular territory, especially if in the vertebrobasilar distribution
(3) a Glasgow Coma Score <= 10 during the first 3 days after admission (Figure 2, page 979; GCS <= 11 on day 1, <= 10 on day 2, <= 9 on day 3)
where:
• A patient with a single small infarct in the distribution of the middle cerebral artery had the lowest risk of nosocomial pneumonia.
Performance:
• The logistic regression model developed by the authors (equation not given in paper) showed a sensitivity of 97.4% and specificity of 45.5%.
