@article {6193, title = {Epidemiology and long-term clinical and biologic risk factors for pneumonia in community-dwelling older Americans: analysis of three cohorts.}, journal = {Chest}, volume = {144}, year = {2013}, month = {2013 Sep}, pages = {1008-1017}, abstract = {

BACKGROUND: Preventing pneumonia requires better understanding of incidence, mortality, and long-term clinical and biologic risk factors, particularly in younger individuals.

METHODS: This was a cohort study in three population-based cohorts of community-dwelling individuals. A derivation cohort (n = 16,260) was used to determine incidence and survival and develop a risk prediction model. The prediction model was validated in two cohorts (n = 8,495). The primary outcome was 10-year risk of pneumonia hospitalization.

RESULTS: The crude and age-adjusted incidences of pneumonia were 6.71 and 9.43 cases/1,000 person-years (10-year risk was 6.15\%). The 30-day and 1-year mortality were 16.5\% and 31.5\%. Although age was the most important risk factor (range of crude incidence rates, 1.69-39.13 cases/1,000 person-years for each 5-year increment from 45-85 years), 38\% of pneumonia cases occurred in adults \< 65 years of age. The 30-day and 1-year mortality were 12.5\% and 25.7\% in those \< 65 years of age. Although most comorbidities were associated with higher risk of pneumonia, reduced lung function was the most important risk factor (relative risk = 6.61 for severe reduction based on FEV1 by spirometry). A clinical risk prediction model based on age, smoking, and lung function predicted 10-year risk (area under curve [AUC] = 0.77 and Hosmer-Lemeshow [HL] C statistic = 0.12). Model discrimination and calibration were similar in the internal validation cohort (AUC = 0.77; HL C statistic, 0.65) but lower in the external validation cohort (AUC = 0.62; HL C statistic, 0.45). The model also calibrated well in blacks and younger adults. C-reactive protein and IL-6 were associated with higher pneumonia risk but did not improve model performance.

CONCLUSIONS: Pneumonia hospitalization is common and associated with high mortality, even in younger healthy adults. Long-term risk of pneumonia can be predicted in community-dwelling adults with a simple clinical risk prediction model.

}, keywords = {Age Factors, Aged, Aged, 80 and over, Community-Acquired Infections, Comorbidity, Female, Follow-Up Studies, Hospitalization, Humans, Incidence, Male, Middle Aged, Pneumonia, Prognosis, Prospective Studies, Risk Assessment, Risk Factors, Survival Rate, Time Factors}, issn = {1931-3543}, doi = {10.1378/chest.12-2818}, author = {Yende, Sachin and Alvarez, Karina and Loehr, Laura and Folsom, Aaron R and Newman, Anne B and Weissfeld, Lisa A and Wunderink, Richard G and Kritchevsky, Stephen B and Mukamal, Kenneth J and London, Stephanie J and Harris, Tamara B and Bauer, Doug C and Angus, Derek C} }