Incidence and characteristics of aspiration pneumonia in adults in Beijing, China, 2011–2017

This study aimed to estimate aspiration pneumonia (AP) incidence and describe comorbid characteristics and mortality in Beijing, China.A historical cohort study was conducted based on medical claim records.Patients admitted with a primary diagnosis of AP were identified from approximately 12 million adults who enrolled in the Urban Employee Basic Medical Insurance program in Beijing, China, from January 2011 to December 2017. The incidences of AP and pneumonia with risk factors for aspiration (PRFA) were estimated by a Poisson distribution. The estimated annual percentage change was reported to represent the average percentage change in incidence per year. Characteristics and 6-month and 1-year all-cause mortality rates for AP and suspected AP patients were described and compared with community-acquired pneumonia (CAP).The incidence rates of hospitalized AP and PRFA were 9.4 (95% confidence interval [CI]: 7.6, 11.3) and 102.9 (95% CI: 95.8, 110.3) per 100,000 person-years, respectively. The incidences increased rapidly with age and were stable across the observed years. Patients with AP and PRFA possessed a greater burden of comorbidities than CAP (mean age-adjusted Charlson comorbidity indices for AP: 7.72, PRFA: 7.83, and CAP: 2.84). The 6-month and 1-year all-cause mortality rates for those with AP and PRFA were higher than those for patients with CAP (6-month mortality, AP: 35.2%, PRFA: 21.8%, CAP: 11.1%; 1-year mortality, AP: 42.7%, PRFA: 26.6%, CAP: 13.2%).The incidence of AP and PRFA in Beijing was reported, presenting a full picture of the disease burden. The results provide baseline information for AP prevention.