biostudies-literatureYende SNational Institute of Environmental Health SciencesNational Institute of Neurological Disorders and StrokeIntramural NIH HHSNIA NIH HHSNational Heart, Lung, and Blood InstituteNHLBI NIH HHSNINR NIH HHSNational Institutes of HealthNIGMS NIH HHSNational Institute on Aging1008-1017https://www.ebi.ac.uk/biostudies/studies/S-EPMC3760741biostudies-literatureUnknown144(3)<h4>Background</h4>Preventing pneumonia requires better understanding of incidence, mortality, and long-term clinical and biologic risk factors, particularly in younger individuals.<h4>Methods</h4>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.<h4>Results</h4>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 &lt; 65 years of age. The 30-day and 1-year mortality were 12.5% and 25.7% in those &lt; 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.<h4>Conclusions</h4>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.ChestEpidemiology and long-term clinical and biologic risk factors for pneumonia in community-dwelling older Americans: analysis of three cohorts.PMC3760741N01-HC-55021N01-HC-55020N01-HC-55222N01-HC-85079R01 AG028050N01-HC-55022U01 HL080295N01HC55019N01HC55018R56 AG023629N01HC55016N01HC55015R01-NR012459N01HC85081N01-HC-85080N01HC85082R01 AG023629N01HC85080HHSN268201200036CN01HC85086N01HC85083N01-HC-55018N01-HC-55016N01-HC-55015N01-HC-85083R01-AG028050N01-HC-85081N01-HC-55019N01-HC-85082N01HC55022N01HC55021N01HC55020HL080295N01-AG-6-2106R01 NR012459K23 GM083215HHSN268200800007CN01-AG-6-2101N01-AG-6-2103N01HC55222R01 HL080295N01HC85079AG-023629K23GM083215H01-HC-85086Kritchevsky SBMukamal KJAngus DCAlvarez KFolsom ARWunderink RGBauer DCLondon SJWeissfeld LAYende SHarris TBNewman ABLoehr LAtherosclerosis Risk in Communities Study, the Cardiovascular Health Study, and the Health, Aging, and Body Composition StudyfalseEpidemiology and long-term clinical and biologic risk factors for pneumonia in community-dwelling older Americans: analysis of three cohorts.<h4>Background</h4>Preventing pneumonia requires better understanding of incidence, mortality, and long-term clinical and biologic risk factors, particularly in younger individuals.<h4>Methods</h4>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.<h4>Results</h4>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 &lt; 65 years of age. The 30-day and 1-year mortality were 12.5% and 25.7% in those &lt; 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.<h4>Conclusions</h4>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.2013-01-01T00:00:00Z2013 Sep2025-05-18T10:53:04.323Z2025-05-18T10:53:04.323ZS-EPMC37607412374410610.1378/chest.12-2818