Baldo Vincenzo, Cocchio Silvia, Gallo Tolinda, Furlan Patrizia, Romor Pierantonio, Bertoncello Chiara, Buja Alessandra, Baldovin Tatjana
Department of Cardiac, Thoracic, and Vascular Sciences, Hygiene and Public Health Unit, University of Padua, Padua, Italy.
EuroHealth Net, Friuli Venezia Giulia Region Health Directorate, Udine, Italy.
PLoS One. 2016 Nov 15;11(11):e0166637. doi: 10.1371/journal.pone.0166637. eCollection 2016.
Community-acquired pneumonia (CAP) is an important cause of illness and death worldwide, particularly among the elderly. Previous studies on the factors associated with mortality in patients hospitalized for CAP revealed a direct association between the type of microorganism involved, the characteristics of the patient and mortality. Vaccination status against pneumococcal disease was not considered. We conducted a retrospective analysis on the mortality rates after a first hospitalization for CAP in north-east Italy with a view to examining especially the role of anti-pneumococcal vaccination as a factor associated with pneumonia-related mortality at one year.
Between 2012-2013, patients aged 65+ hospitalized with a primary diagnosis of CAP, identified based on International Classification of Diseases, Ninth Revision, Clinical Modification codes 481-486, were enrolled in the study only once. Patients were divided into three groups by pneumococcal vaccination status: 1) 13-valent pneumococcal conjugate vaccine (PCV13) prior to their hospitalization; 2) 23-valent pneumococcal polysaccharide vaccine (PPV23) within 5 years before hospitalization and 3) unvaccinated or PPV23 more than 5 years prior to admission. Gender, age, length of hospital stay and influenza vaccination were considered. Comorbidities were ascertained by means of a properly coded diagnosis. Every patient was followed up for 1 year and the outcome investigated was mortality for any cause and for pneumonia.
A total of 4,030 patient were included in the study; mean age at the time of admission to hospital was 84.3±7.7; 50.9% were female. 74.2% of subjects had at least one comorbidity; 73.7% has been vaccinated against influenza. Regard to pneumococcal vaccine, 80.4% of patients were not vaccinated, 14.5% vaccinated with PPV23 and 5.1% with PCV13. The 1-year survival rates after hospitalization for pneumonia were 83.6%, 85.9% and 89.3% in the unvaccinated, PPV23 and PCV13 groups, respectively. Regression analysis indicated that the risk of death due to pneumonia increased significantly with age (adjusted OR: 1.073; 1.061-1.085), shorter hospital stay (adjusted OR: 0.981; 0.971-0.990), and male gender (adjusted OR: 1.372; 1.165-1.616). The model also confirmed the pneumococcal 13-valent conjugated vaccine as an independent protective factor for mortality-related pneumonia (adjusted OR: 0.599; 0.390-0.921).
The main finding of our observational cohort study is a high mortality rate among elderly patients admitted to hospital for pneumonia. The present study suggests a protective role for PCV13 vaccination.
社区获得性肺炎（CAP）是全球范围内发病和死亡的重要原因，在老年人中尤为如此。先前关于因CAP住院患者死亡率相关因素的研究表明，所涉及的微生物类型、患者特征与死亡率之间存在直接关联。但未考虑肺炎球菌疾病的疫苗接种状况。我们对意大利东北部首次因CAP住院后的死亡率进行了回顾性分析，尤其旨在考察抗肺炎球菌疫苗接种作为与一年期肺炎相关死亡率相关因素的作用。
在2012年至2013年期间，年龄在65岁及以上、以CAP为主要诊断入院的患者（根据《国际疾病分类，第九版，临床修订本》编码481 - 486确定）仅纳入研究一次。患者按肺炎球菌疫苗接种状况分为三组：1）住院前接种13价肺炎球菌结合疫苗（PCV13）；2）住院前5年内接种23价肺炎球菌多糖疫苗（PPV23）；3）未接种或入院前5年多以前接种PPV23。考虑了性别、年龄、住院时间和流感疫苗接种情况。通过适当编码的诊断确定合并症。对每位患者随访1年，调查的结局是任何原因导致的死亡率以及肺炎死亡率。
共4030例患者纳入研究；入院时平均年龄为84.3±7.7岁；50.9%为女性。74.2%的受试者至少有一种合并症；73.7%接种过流感疫苗。关于肺炎球菌疫苗，80.4%的患者未接种，14.5%接种PPV23，5.1%接种PCV13。未接种组、PPV23组和PCV13组肺炎住院后1年生存率分别为83.6%、85.9%和89.3%。回归分析表明，因肺炎死亡的风险随年龄显著增加（调整后OR：1.073；1.061 - 1.085）、住院时间缩短（调整后OR：0.981；0.971 - 0.990）以及男性（调整后OR：1.372；1.165 - 1.616）。该模型还证实13价肺炎球菌结合疫苗是与死亡率相关肺炎的独立保护因素（调整后OR：0.599；0.390 - 0.921）。
我们的观察性队列研究的主要发现是因肺炎入院的老年患者死亡率高。本研究表明PCV13疫苗接种具有保护作用。
