Pneumonia in the Noninstitutionalized Older Population

Abstract

Background: Pneumonia is a common and potentially serious disease, with an incidence of ca. 300 per 100 000 persons per year. Until now, there have been only a few population-based studies of risk factors for pneumonia.

Methods: From 2000 to 2002, nearly 10 000 persons aged 50 to 75 were recruited into the prospective ESTHER cohort study while visiting their family physician for a check-up. The mean duration of follow-up was 10.6 years. Data on newly diagnosed pneumonia were acquired from the participants and their physicians by means of standardized questionnaires. Potential associations with various predictors were studied in survival-time regression models.

Results: 435 participants had pneumonia at least once during follow-up. The cumulative 10-year-incidence was 4.5% (95% confidence interval [4.0; 4.9]). Multiple regression revealed that age (relative risk [RR]: 1.43 [1.22; 1.67] per 10 years), current cigarette smoking (RR: 1.56 [1.19; 2.05], compared with never having smoked), and known congestive heart failure (RR: 1.65 [1.24; 2.20]) were independently associated with an elevated risk of pneumonia. The risk was insignificantly elevated in persons with diabetes mellitus (RR: 1.29 [0.98; 1.68]). Alcohol consumption, obesity, stroke, and cancer were not associated with an elevated risk of pneumonia in age- and sex-adjusted analyses.

Conclusion: Pneumonia plays an important role in the medical care of non-institutionalized older people. With the aid of the predictors identified in this study, primary care physicians can identify patients at risk, smokers can gain additional motivation to quit, treatment compliance can be increased, and patients may become more willing to be vaccinated as recommended in the current guidelines.

Figure 1

Cumulative incidence curves stratified for selected predictors, for pneumonia (solid lines: main endpoint) and dropping out of the study because of death (dashed lines: competing event) in the prospective ESTHER cohort study. ESTHER, an epidemiologic study on potential opportunities for the prevention, early detection, and improved treatement of chronic diseases among older persons in Germany.