Epidemiology and long-term clinical and biologic risk factors for pneumonia in community-dwelling older Americans: analysis of three cohorts.
Chest. 2013 Jun 6;
Authors: Yende S, Alvarez K, Loehr L, Folsom AR, Newman AB, Weissfeld LA, Wunderink RG, Kritchevsky SB, Mukamal KJ, London SJ, Harris TB, Bauer DC, Angus DC
ABSTRACT BACKGROUND: Preventing pneumonia requires better understanding of incidence, mortality, and long-term clinical and biologic risk factors, particularly in younger individuals. METHODS: Cohort study in 3 population-based cohorts of community-dwelling individuals. Derivation cohort (n=16,260) was used to determine incidence and survival and develop a risk prediction model. The prediction model was validated in 2 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. The 30-day and 1-year mortality were 12.5% and 25.7% in those <65 years. 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 forced expiratory volume 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 statistic=0.12). Model discrimination and calibration was similar in the internal validation cohort (AUC=0.77 and HL C statistic was 0.65), but lower in the external validation cohort (AUC=0.62, HL C statistic was 0.45). The model also calibrated well blacks, and younger adults. C-reactive protein and interleukin-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.
PMID: 23744106 [PubMed - as supplied by publisher]