Trial flow
The search strategy generated a total of 6,821 citations (3,516 from
Pubmed and 3,205 from ISI web of science). All the documents were
selected strictly according to the criteria described above. Subsequent
scrutiny of the title and abstracts led to the exclusion of 6,777 of
these articles either for they were irrelevant to the aim of this
meta-analysis or for duplication. 21 articles were further excluded for
un-relation to our aim. The full publications were obtained for the
remaining 23 articles.
According to inclusion criteria, 9 articles were further excluded,
leaving 14 studies eligible for this article[14-27]. Specially, two
articles were excluded either for overlapping patients with included
studies[3], or for they defined the degree of severity of Covid-19
with the different criteria[3, 28]. One article reporting outcome
regarding 55 2019-nCoV was also excluded from this meta-analysis, since
it did not reported origin of patients[29]. For three articles
reporting outcome in Wuhan Tongji hoptital[17, 30, 31], three
articles reporting outcome in Jiangsu Province[27, 32, 33] and three
article reporting outcome in Zhejiang province[33-35], only the
study with larger simple volume was in included in this article[17,
27, 33]. No additional articles were retrieved from the citation list
of included studies. The details of study selection flow were explicitly
described in Figure 1.