Supplementary Material for: Pneumonia Is Associated with Increased Mortality in Hospitalized COPD Patients: A Systematic Review and Meta-Analysis

Background: Patients with chronic obstructive pulmonary disease (COPD) are at a heightened risk of pneumonia. Whether coexisting community-acquired pneumonia (CAP) can predict increased mortality in hospitalized COPD patients is still controversial. Objective: This systematic review and meta-analysis aims to assess the association between CAP and mortality and morbidity in COPD patients hospitalized for acute worsening of respiratory symptoms. Methods: In this review, cohort studies and case-control studies investigating the impact of CAP in hospitalized COPD patients were retrieved from 4 electronic databases from inception until December 2019. Methodological quality of included studies was assessed using Newcastle-Ottawa Quality Assessment Scale. The primary outcome was mortality. The secondary outcomes included length of hospital stay, need for mechanical ventilation, intensive care unit (ICU) admission, length of ICU stay, and readmission rate. The Mantel-Haenszel method and inverse variance method were used to calculate pooled relative risk (RR) and mean difference (MD), respectively. Results: A total of 18 studies were included. The presence of CAP was associated with higher mortality (RR = 1.85; 95% CI: 1.50–2.30; p < 0.00001), longer length of hospital stay (MD = 1.89; 95% CI: 1.19–2.59; p < 0.00001), more need for mechanical ventilation (RR = 1.48; 95% CI: 1.32–1.67; p < 0.00001), and more ICU admissions (RR = 1.58; 95% CI: 1.24–2.03; p = 0.0002) in hospitalized COPD patients. CAP was not associated with longer ICU stay (MD = 5.2; 95% CI: −2.35 to 12.74; p = 0.18) or higher readmission rate (RR = 1.02; 95% CI: 0.96–1.09; p = 0.47). Conclusion: Coexisting CAP may be associated with increased mortality and morbidity in hospitalized COPD patients, so radiological confirmation of CAP should be required and more attention should be paid to these patients.

背景：慢性阻塞性肺疾病（chronic obstructive pulmonary disease, COPD）患者罹患肺炎的风险显著升高。合并社区获得性肺炎（community-acquired pneumonia, CAP）是否可预测住院慢性阻塞性肺疾病患者的死亡率升高，目前仍存在争议。
目的：本系统评价与meta分析旨在评估因呼吸道症状急性加重住院的慢性阻塞性肺疾病患者中，社区获得性肺炎与死亡率及发病率的关联。
方法：本研究从4个电子数据库建库至2019年12月，检索探讨社区获得性肺炎对住院慢性阻塞性肺疾病患者影响的队列研究及病例对照研究。采用纽卡斯尔-渥太华质量评价量表（Newcastle-Ottawa Quality Assessment Scale）评价纳入研究的方法学质量。主要结局指标为死亡率，次要结局指标包括住院时长、机械通气需求、重症监护病房（intensive care unit, ICU）入住率、ICU停留时长及再入院率。分别采用Mantel-Haenszel法与倒方差法计算合并相对危险度（relative risk, RR）与均数差（mean difference, MD）。
结果：共纳入18项研究。合并社区获得性肺炎的住院慢性阻塞性肺疾病患者死亡率更高（RR=1.85；95%置信区间CI：1.50~2.30；P<0.00001），住院时长更长（MD=1.89；95%置信区间CI：1.19~2.59；P<0.00001），机械通气需求更高（RR=1.48；95%置信区间CI：1.32~1.67；P<0.00001），ICU入住率更高（RR=1.58；95%置信区间CI：1.24~2.03；P=0.0002）。而合并社区获得性肺炎与住院慢性阻塞性肺疾病患者的ICU停留时长（MD=5.2；95%置信区间CI：−2.35至12.74；P=0.18）及再入院率（RR=1.02；95%置信区间CI：0.96~1.09；P=0.47）无显著关联。
结论：住院慢性阻塞性肺疾病患者合并社区获得性肺炎可能与死亡率及发病率升高相关，因此需对这类患者进行社区获得性肺炎的影像学确认，并给予更多关注。