Risk factors for nosocomial pneumonia in a geriatric hospital: a control-case one-center study

To determine the risk factors (RFs) and the incidence of nosocomial pneumonia (NP).

Control/case study conducted from January 1 to April 15, 1999. Prospective enrollment.

Geriatric university hospital with long-, intermediate-, and short-term care facilities.

Inpatients aged 65 and older with NP.

NP diagnosis relied on at least two clinical signs of respiratory infection and on chest radiography. Each NP case was randomly paired with two controls and followed up for 30 days to determine complication and mortality rates. RFs between cases and controls were compared (chi-square test, odds ratio (OR), 95% confidence interval, significance level P =.05). RFs that were significant in univariate analysis were tested using multivariate analysis and logistic regression.

Seventy-five cases of NP were diagnosed in 2,142 patients. The average incidence rate was 3.5% (short-term facilities = 0.5%; intermediate-term facilities = 8.3%; long-term care facilities = 5.3%). The complication rate was 58.1%. The most frequent complications were recurrent NP, heart and respiratory failure, phlebitis, and pressure ulcers. The NP mortality rate was 12.2%. The independent RFs of NP were a history of NP during the previous 6 months (OR = 4.50) and oxygen therapy (OR = 16.15), P <.001. Additional RFs were severe malnutrition, heart failure, prescription of antibiotics during the month preceding the emerging NP, eating dependency, and feeding by nasogastric tube.

The main RF for NP is a history of pneumonia. NP prevention in geriatrics should rely on early management of respiratory infections and malnutrition, surveillance of oxygen therapy and enteral feeding, rational use of antibiotics, and adaptation to the patient's dependency.