The worldwide COVID-19 pandemic has turned into a global catastrophic public health crisis, and the conclusion about the risk factors of hospital death in COVID-19 patients is not uniform.

To explore risk factors of in-hospital death in patients with COVID-19 by a meta-analysis.

Case-control studies about risk factors of in-hospital death in COVID-19 patients were searched from databases of the Cochrane Library, ScienceDirect, PubMed, Medline, Wanfang Data, CNKI and CQVIP from inception to October 1, 2021. Literature screening, data extraction and methodological quality assessment were conducted. Meta-analysis was performed using Stata 15.1. Meta-regression was used to explore the potential sources of heterogeneity.

Eighty studies were included which involving 405 157 cases〔349 923 were survivors (86.37%) , and 55 234 deaths (13.63%) 〕, that were rated as being of high quality by the Newcastle-Ottawa Scale. Meta-analysis showed that being male〔OR=1.49, 95%CI (1.41, 1.57) , P<0.001) , older age〔WMD=10.44, 95%CI (9.79, 11.09) , P<0.001〕, dyspnoea〔OR=2.09, 95%CI (1.80, 2.43) , P<0.001〕, fatigue〔OR=1.49, 95%CI (1.31, 1.69) , P<0.001〕, obesity〔OR=1.46, 95%CI (1.43, 1.50) , P<0.001〕, smoking〔OR=1.18, 95%CI (1.14, 1.23) , P<0.001〕, stroke〔OR=2.26, 95%CI (1.41, 3.62) , P<0.001〕, kidney disease〔OR=3.62, 95%CI (3.26, 4.03) , P<0.001〕, cardiovascular disease〔OR=2.34, 95%CI (2.21, 2.47) , P<0.001〕, hypertension〔OR=2.23, 95%CI (2.10, 2.37) , P<0.001〕, diabetes〔OR=1.84, 95%CI (1.74, 1.94) , P<0.001〕, cancer〔OR=1.86, 95%CI (1.69, 2.05) , P<0.001〕, pulmonary disease〔OR=2.38, 95%CI (2.19, 2.58) , P<0.001〕, liver disease〔OR=1.65, 95%CI (1.36, 2.01) , P<0.001〕, elevated levels of white blood cell count〔WMD=2.03, 95%CI (1.74, 2.32) , P<0.001〕, neutrophil count〔WMD=1.77, 95%CI (1.49, 2.05) , P<0.001〕, total bilirubin〔WMD=3.19, 95%CI (1.96, 4.42) , P<0.001〕, aspartate transaminase〔WMD=13.02, 95%CI (11.70, 14.34) , P<0.001〕, alanine transaminase〔WMD=2.76, 95%CI (1.68, 3.85) , P<0.001〕, lactate dehydrogenase〔WMD=166.91, 95%CI (150.17, 183.64) , P<0.001〕, blood urea nitrogen〔WMD=3.11, 95%CI (2.61, 3.60) , P<0.001〕, serum creatinine〔WMD=22.06, 95%CI (19.41, 24.72) , P<0.001〕, C-reactive protein〔WMD=76.45, 95%CI (71.33, 81.56) , P<0.001〕, interleukin-6〔WMD=28.21, 95%CI (14.98, 41.44) , P<0.001〕, and erythrocyte sedimentation rate〔WMD=8.48, 95%CI (5.79, 11.17) , P<0.001〕 were associated with increased risk of in-hospital death for patients with COVID-19, while myalgia〔OR=0.73, 95%CI (0.62, 0.85) , P<0.001〕, cough〔OR=0.87, 95%CI (0.78, 0.97) , P=0.013〕, vomiting〔OR=0.73, 95%CI (0.54, 0.98) , P=0.030〕, diarrhoea〔OR=0.79, 95%CI (0.69, 0.92) , P=0.001〕, headache〔OR=0.55, 95%CI (0.45, 0.68) , P<0.001〕, asthma〔OR=0.73, 95%CI (0.69, 0.78) , P<0.001〕, low body mass index〔WMD=-0.58, 95%CI (-1.10, -0.06) , P=0.029〕, decreased lymphocyte count〔WMD=-0.36, 95%CI (-0.39, -0.32) , P<0.001〕, decreased platelet count〔WMD=-38.26, 95%CI (-44.37, -32.15) , P<0.001〕, increased D-dimer〔WMD=0.79, 95%CI (0.63, 0.95) , P<0.001〕, longer prothrombin time〔WMD=0.78, 95%CI (0.61, 0.94) , P<0.001〕, lower albumin〔WMD=-1.88, 95%CI (-2.35, -1.40) , P<0.001〕, increased procalcitonin〔WMD=0.27, 95%CI (0.24, 0.31) , P<0.001〕, and increased cardiac troponin〔WMD=0.04, 95%CI (0.03, 0.04) , P<0.001〕were associated with decreased risk of in-hospital death due to COVID-19. According to the meta-regression result, the heterogeneity in gender, renal disease, cardiovascular diseases, asthma, white blood cell count, neutrophil count, platelet count, hemoglobin, and urea nitrogen differed siangificnatly by country (P<0.05) .

The risk of in-hospital death due to COVID-19 may be increased by 25 factors (including being male, older age, dyspnoea, fatigue, obesity, smoking, stroke, kidney disease, cardiovascular disease, hypertension, diabetes, cancer, pulmonary disease, liver disease, elevated levels of white blood cells, neutrophil count, total bilirubin, aspartate transaminase, alanine transaminase, lactate dehydrogenase, blood urea nitrogen, serum creatinine, C-reactive protein, interleukin-6, and erythrocyte sedimentation rate) , and may be decreased by 13 factors (including myalgia, cough, vomiting, diarrhoea, headache, asthma, low body mass index, decreased lymphocyte count and platelet count, increased D-dimer, longer prothrombin time, lower albumin, increased procalcitonin and cardiac troponin) . The conclusion drawn from this study needs to be further confirmed by high-quality, multicenter, large-sample, real-world studies.

新型冠状病毒感染（COVID-19）在全世界大规模流行，已经演变成一场全球的灾难性公共卫生危机；目前关于COVID-19患者院内死亡危险因素的结论尚不统一。

通过Meta分析探讨COVID-19患者院内死亡的相关危险因素。

计算机检索Cochrane Library、ScienceDirect、PubMed、Medline、万方数据知识服务平台、中国知网、维普期刊资源整合服务平台，搜索已发表的关于COVID-19患者院内死亡的病例对照研究，检索时限为建库至2021-10-01。筛选文献、提取资料并评价文献质量，采用Stata 15.1软件进行Meta分析，采用Meta回归探索可能的异质性来源。

最终纳入80篇文献，共405 157例患者，其中存活组349 923例（86.37%），死亡组55 234例（13.63%）。根据纽卡斯尔-渥太华量表（NOS）评分，均为高质量文献。Meta分析结果显示，男性〔OR=1.49，95%CI（1.41，1.57），P<0.001〕、年龄大〔WMD=10.44，95%CI（9.79，11.09），P<0.001〕、呼吸困难〔OR=2.09，95%CI（1.80，2.43），P<0.001〕、疲劳〔OR=1.49，95%CI（1.31，1.69），P<0.001〕、肥胖〔OR=1.46，95%CI（1.43，1.50），P<0.001〕、吸烟〔OR=1.18，95%CI（1.14，1.23），P<0.001〕、脑卒中〔OR=2.26，95%CI（1.41，3.62），P<0.001〕、肾脏疾病〔OR=3.62，95%CI（3.26，4.03），P<0.001〕、心血管疾病〔OR=2.34，95%CI（2.21，2.47），P<0.001〕、高血压〔OR=2.23，95%CI（2.10，2.37），P<0.001〕、糖尿病〔OR=1.84，95%CI（1.74，1.94），P<0.001〕、肿瘤〔OR=1.86，95%CI（1.69，2.05），P<0.001〕、肺部疾病〔OR=2.38，95%CI（2.19，2.58），P<0.001〕、肝脏疾病〔OR=1.65，95%CI（1.36，2.01），P<0.001〕、白细胞计数升高〔WMD=2.03，95%CI（1.74，2.32），P<0.001〕、中性粒细胞计数升高〔WMD=1.77，95%CI（1.49，2.05），P<0.001〕、总胆红素升高〔WMD=3.19，95%CI（1.96，4.42），P<0.001〕、天冬氨酸氨基转移酶升高〔WMD=13.02，95%CI（11.70，14.34），P<0.001〕、丙氨酸氨基转移酶升高〔WMD=2.76，95%CI（1.68，3.85），P<0.001〕、乳酸脱氢酶升高〔WMD=166.91，95%CI（150.17，183.64），P<0.001〕、尿素氮升高〔WMD=3.11，95%CI（2.61，3.60），P<0.001〕、肌酐升高〔WMD=22.06，95%CI（19.41，24.72），P<0.001〕、C反应蛋白升高〔WMD=76.45，95%CI（71.33，81.56），P<0.001〕、白介素6升高〔WMD=28.21，95%CI（14.98，41.44），P<0.001〕、红细胞沉降率升高〔WMD=8.48，95%CI（5.79，11.17），P<0.001〕是COVID-19患者院内死亡的危险因素；肌痛〔OR=0.73，95%CI（0.62，0.85），P<0.001〕、咳嗽〔OR=0.87，95%CI（0.78，0.97），P=0.013〕、呕吐〔OR=0.73，95%CI（0.54，0.98），P=0.030〕、腹泻〔OR=0.79，95%CI（0.69，0.92），P=0.001〕、头痛〔OR=0.55，95%CI（0.45，0.68），P<0.001〕、哮喘〔OR=0.73，95%CI（0.69，0.78），P<0.001〕、体质指数降低〔WMD=-0.58，95%CI（-1.10，-0.06），P=0.029〕、淋巴细胞计数降低〔WMD=-0.36，95%CI（-0.39，-0.32），P<0.001〕、血小板计数降低〔WMD=-38.26，95%CI（-44.37，-32.15），P<0.001〕、D-二聚体升高〔WMD=0.79，95%CI（0.63，0.95），P<0.001〕、凝血酶原时间升高〔WMD=0.78，95%CI（0.61，0.94），P<0.001〕、白蛋白降低〔WMD=-1.88，95%CI（-2.35，-1.40），P<0.001〕、降钙素原升高〔WMD=0.27，95%CI（0.24，0.31），P<0.001〕、肌钙蛋白升高〔WMD=0.04，95%CI（0.03，0.04），P<0.001〕是COVID-19患者院内死亡的保护因素。Meta回归结果显示，国家对性别、肾脏疾病、心血管疾病、哮喘、白细胞计数、中性粒细胞计数、血小板计数、血红蛋白、尿素氮的异质性均有统计学意义（P<0.05）。

男性、年龄大、呼吸困难、疲劳、肥胖、吸烟、脑卒中、肾脏疾病、心血管疾病、高血压、糖尿病、肿瘤、肺部疾病、肝脏疾病，白细胞计数、中性粒细胞计数、总胆红素、天冬氨酸氨基转移酶、丙氨酸氨基转移酶、乳酸脱氢酶、尿素氮、肌酐、C反应蛋白、白介素6、红细胞沉降率升高可能是COVID-19患者院内死亡的危险因素，肌痛、呕吐、腹泻、头痛、哮喘、体质指数降低、淋巴细胞计数降低、血小板计数降低、D-二聚体升高、凝血酶原时间升高、白蛋白降低、降钙素原升高、肌钙蛋白升高可能是COVID-19患者院内死亡的保护因素。本研究所得出的结论，尚需更多高质量、多中心、大样本、真实世界的研究进一步证实。