Supplementary Material for: Clinical Utility of Surgical Lung Biopsy for Patients with Acute Respiratory Distress Syndrome: A Systematic Review and Meta-Analysis

<b><i>Background:</i></b> Surgical lung biopsy (SLB) is performed in patients with acute respiratory distress syndrome (ARDS); however, its clinical utility remains unclear. <b><i>Objectives:</i></b> We categorized the pathological diagnoses and investigated the predictive value for short-term mortality. <b><i>Method:</i></b> Three electronic databases (MEDLINE, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov) were searched for the included studies. The QUADAS-2 was used to evaluate the risk of bias and its applicability. The types and populations of pathological diagnoses were investigated. The pooled sensitivity, positive likelihood ratio (LR+), negative likelihood ratio (LR−), and diagnostic odds ratio (DOR) were estimated at a fixed specificity. Hierarchical summary receiver operating characteristic curves were drawn. <b><i>Results:</i></b> A total of 16 studies that enrolled 758 patients were included. The pathological diagnoses were as follows: diffuse alveolar damage (DAD) 29.9%; infection 24.7%; interstitial lung disease 17.2%; malignancy 3.6%; cardiovascular disease 3.6%; drug toxicity 2.3%; connective tissue disease 2.2%; allergic disease 1.1%; and nonspecific diagnosis 15.4%. To predict short-term mortality, 13 studies that enrolled 613 patients used DAD as an index test and recorded a mortality rate of 56.9% (349 of 613 patients). A total of 3 studies that used index tests other than DAD were excluded. The pooled sensitivity, fixed specificity, LR+, LR−, and DOR were 0.46 (95% confidence interval [CI]: 0.29–0.56), 0.69, 1.48 (95% CI: 0.92–1.81), 0.78 (95% CI: 0.63–1.03), and 1.90 (95% CI: 0.89–2.86), respectively. <b><i>Conclusions:</i></b> SLB is unlikely to provide a specific diagnosis and should not be recommended for confirming DAD or predicting ARDS prognosis.

**背景：** 外科肺活检（Surgical Lung Biopsy，SLB）在急性呼吸窘迫综合征（acute respiratory distress syndrome，ARDS）患者中开展，但其临床应用价值仍不明确。
**研究目标：** 本研究对病理诊断进行分类，并探讨其对患者短期死亡率的预测价值。
**研究方法：** 检索MEDLINE、Cochrane对照试验中心注册库（Cochrane Central Register of Controlled Trials）以及ClinicalTrials.gov三个电子数据库，纳入符合标准的相关研究。采用QUADAS-2量表评估偏倚风险及研究适用性。分析病理诊断的类型与受试人群特征。在固定特异度下，合并计算合并灵敏度、阳性似然比（positive likelihood ratio，LR+）、阴性似然比（negative likelihood ratio，LR−）及诊断比值比（diagnostic odds ratio，DOR）。绘制分层汇总受试者工作特征曲线。
**研究结果：** 最终纳入16项研究，共计758例患者。病理诊断类型及占比分别为：弥漫性肺泡损伤（diffuse alveolar damage，DAD）29.9%、感染24.7%、间质性肺疾病17.2%、恶性肿瘤3.6%、心血管疾病3.6%、药物毒性2.3%、结缔组织病2.2%、变态反应性疾病1.1%、非特异性诊断15.4%。在预测短期死亡率的亚组分析中，13项研究共纳入613例患者，以DAD作为指标试验，该组患者死亡率为56.9%（613例中349例）。另有3项采用非DAD指标试验的研究被排除。合并灵敏度、固定特异度、LR+、LR−及DOR分别为0.46（95%置信区间[CI]：0.29–0.56）、0.69、1.48（95%CI：0.92–1.81）、0.78（95%CI：0.63–1.03）及1.90（95%CI：0.89–2.86）。
**结论：** 外科肺活检难以提供明确的特异性病理诊断，因此不推荐用于确诊DAD或预测ARDS患者的预后。