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. 2020 Sep 15:bmjebm-2020-111536. doi: 10.1136/bmjebm-2020-111536

Table 1.

Study characteristics, outcomes and laboratory biomarkers

Study Country Sample size (n) Study period Mean/median age (years) Male (n) Study design Outcome Laboratory biomarkers
Huang et al43 China 41 16 Dec 2019 to 2 Jan 2020 49 30 Prospective single-centre ICU vs non-ICU Lymphocyte count, AST, PCT, LDH, CK, creatinine and platelet count
Guan et al5 China 1099 11 Dec 2019 to 29 Jan 2020 47 637 Retrospective multicentre Severe vs non-severe* Lymphocyte count, ALT, AST, CRP, PCT,
LDH, CK, creatinine, D-dimer and platelet count
Wang et al56 China 138 1 Jan 2020 to 28 Jan 2020 56 75 Retrospective single-centre ICU vs non-ICU PCT
Zhang et al57 China 140 16 Jan 2020 to 3 Feb 2020 57 71 Retrospective single-centre Severe vs non-severe† Lymphocyte count, CRP,
PCT, CK and D-dimer
Wang et al58 China 69 16 Jan 2020 to 29 Jan 2020 42 32 Retrospective single-centre SpO2 <90 vs SpO2 >=90 Lymphocyte count, ALT, AST, CRP, PCT and LDH
Zhou et al59 China 191 29 Dec 2019 to 31 Jan 2020 56 119 Retrospective multicentre cohort Survivor vs non-survivor Lymphocyte count, ALT, platelet count, LDH, CK, PCT, creatinine and D-dimer
Chen et al46 China 21 Late Dec 2019 to 27 Jan 2020 56 17 Retrospective single-centre Severe vs moderate† Lymphocyte count, AST, CRP, PCT, LDH and platelet count
Zheng et al60 China 161 17 Jan 2020 to 7 Feb 2020. 45 80 Retrospective single-centre Severe vs non-severe† Lymphocyte count, ALT, AST, CRP, LDH, CK, creatinine and platelet count
Colaneri et al61 Italy 44 21 Feb 2020 to 28 Feb 2020 67.5 28 Retrospective single-centre Severe vs mild‡ Lymphocyte count, CRP, platelet count, LDH and creatinine
Zhao et al62 China 91 16 Jan 2020 to 10 Feb 2020 46 49 Retrospective single-centre Severe vs mild§ Lymphocyte count, ALT, AST, CRP, CK, D-dimer, PCT and creatinine
Paranjpe et al63 USA 1078 27 Feb 2020 to 2 Apr 2020 75 vs 59 627 Retrospective multicentre In-hospital mortality vs
discharged alive		 CRP, PCT, and D-dimer
Goyal et al64 USA 393 3 Mar 2020 to 10 Apr 2020 62.2 238 Retrospective multicentre IMV vs
no IMV		 Lymphocyte count, CRP, platelet count, ALT, AST, creatinine, PCT and D-dimer,
Wan et al65 China 135 23 Jan 2020 to 8 Feb 2020 47 72 Retrospective single-centre Severe vs mild† Lymphocyte count, AST, CK, PCT, creatinine and platelet count
Zhang et al66 China 663 11 Jan 2020 to 6 Feb 2020 55.6 321 Retrospective cohort Severe and critical vs
mild and moderate†		 Lymphocyte count, ALT, AST, CRP and LDH
Zheng et al67 China 34 22 Jan 2020 to 5 Mar 2020 66 23 Retrospective single-centre IMV vs
no IMV¶		 Lymphocyte count
Hong et al68 South Korea 98 Upto Mar 2020 55.4 38 Retrospective single-centre ICU vs non-ICU Lymphocyte count, CRP, platelet count, ALT, AST, PCT, LDH, CK and creatinine
Huang et al69 China 202 22 Jan 2020 to 10 Feb 2020 44 116 Retrospective multicentre Severe vs
non-severe†		 Lymphocyte count, CRP and PCT
Wang et al20 China 65 Jan 2020 57.11 37 Prospective single-centre (Severe+extremely severe) vs
mild†		 Lymphocyte count, CRP,
PCT, LDH, creatinine and D-dimer
Du et al70 China 179 25 Dec 2019 to 7 Feb 2020 57.6 97 Prospective single-centre case cohort Deceased vs survived Lymphocyte count, AST, CRP, PCT, creatinine and D-dimer
Deng et al71 China 65 Until 12 Apr 2020 32.5 vs 35 36 Retrospective cohort study (Severe+critical) vs moderate† Lymphocyte count, ALT, AST, CRP, LDH, creatinine and D-dimer
Jang et al72 Korea 110 19 Feb 2020 to 15 Apr 2020 56.9 48 Retrospective single-centre Severe vs non-severe** Lymphocyte count, CRP, platelet count, ALT, AST, PCT, LDH, CK, creatinine and D-dimer
Khamis et al73 Oman 63 24 Feb 2020 to 24 Apr 2020 48 53 Retrospective case series ICU vs non-ICU Lymphocyte count, CRP, platelet count, LDH, creatinine and D-dimer
Mikami et al74 USA 2820 13 Mar 2020 to 17 Apr 2020 62 vs 76 1611 Retrospective multicentre cohort Survivor vs non-survivor Lymphocyte count, ALT, AST, CRP, LDH, D-dimer and PCT
Shahriarirad et al75 Iran 113 20 Feb 2020 to 20 Mar 2020 53.75 71 Retrospective multicentre Severe vs non-severe* Lymphocyte count, CRP, platelet count and creatinine
Wang et al76 China 275 20 Jan 2020 to 10 Feb 2020 49 128 Retrospective single-centre Severe vs non-severe† Lymphocyte count, AST, LDH, CK, creatinine and D-dimer
Zhang et al77 China 221 2 Jan 2020 to 10 Feb 2020 55 108 Retrospective single-centre Severe vs non-severe† Lymphocyte count and PCT
Jiang et al78 China 59 Feb and Mar 2020 64 29 Retrospective multicentre ICU vs non-ICU Lymphocyte count, AST, platelet count, CK and creatinine
Li et al79 China 548 26 Jan 2020 to 5 Feb 2020 60 279 Ambispective cohort study Severe vs non-severe* Lymphocyte count, CRP,
platelet count, ALT, AST, PCT, LDH, creatinine and D-dimer
Wei et al80 China 276 27 Jan 2020 to 11 Mar 2020 51 155 Retrospective single-centre Severe vs non-severe† Lymphocyte count, CRP,
platelet count, ALT, AST, PCT, LDH, CK, creatinine and D-dimer
Xu et al81 China 239 12 Jan 2020 to 3 Feb 2020 62 143 Retrospective multicentre Survivor vs non-survivor Lymphocyte count, platelet count
Zhang et al82 China 788 17 Jan 2020 12 Feb 2020 Severe—55
Critical—70
Mild—37		 407 Retrospective single-centre (Severe+critical) vs mild† Lymphocyte count, AST,
platelet count and LDH
Ferguson et al83 USA 72 13 Mar 2020 to 2 May 2020 60.4 38 Retrospective multicentre ICU vs non-ICU CRP, PCT, D-dimer
Total   10 491        

*Using the American Thoracic Society guidelines for community-acquired pneumonia.

†WHO and the National Health Commission of China interim guidelines defined disease severity and improvement as follows: Mild cases: the mild clinical symptoms and no pneumonia in imaging. Moderate cases: symptoms like fever and respiratory tract symptoms and so on, and pneumonia can be seen in imaging. Severe cases: meeting any of the following—respiratory distress, respiratory rate ≥30 breaths/min; SpO2 ≤93% at rest; and PaO2/FIO2≤300. Patients with >50% lesion progression within 24–48 hours. Critical/extremely severe cases: if they have one of the following: respiratory failure requiring mechanical ventilation, shock and other organ failure requiring ICU treatment.

‡Patients were included in the mild disease group if they did not need high-flow oxygen support and in the severe disease group if they were provided with high-flow oxygen support.

§Not mentioned.

¶Non-invasive mechanical ventilation (NIV) included nasal oxygen therapy, mask oxygen inhalation and high-flow nasal cannula (HFNC).

**Severe disease was defined as a composite outcome of acute respiratory distress syndrome (ARDS), intensive care unit care, or death. ARDS was diagnosed according to the Berlin definition. SARS-CoV-2 infection was confirmed by real-time reverse transcription PCR assay of nose and/or throat swab samples.

ALT, alanine aminotransferase; AST, aspartate aminotransferase; CK, creatine kinase; CRP, C reactive protein; ICU, intensive care unit; IMV, invasive mechanical ventilation; LDH, lactate dehydrogenase; PCT, procalcitonin.