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We thank Shi et al 1 for their interest and comments on our research article ‘Prevalence and clinical outcomes of COVID-19 in patients with autoimmune diseases: a systematic review and meta-analysis’.2 The following is our point by point reply to their comments.
First, in terms of case-controlled study, we included studies with data regarding the prevalence or clinical outcomes of COVID-19 in patients with autoimmune diseases (ADs) and patients without ADs or the general population. We agree that subgroup analysis according to study design can often be useful in identifying heterogeneity.
Second, we agree that the risk of bias (RoB) assessment is an important step to conduct systematic review and meta-analysis. As Shi et al suggested, several tools are available to assess the RoB of individual studies included in the meta-analysis.3 Meanwhile, the Grades of Recommendation Assessment, Development and Evaluation (GRADE) is a well-validated tool to assess the overall RoB of a meta-analysis.4 As we mentioned in the limitation,2 we found considerable heterogeneities particularly in meta-analyses of the prevalence of COVID-19 and the rate of hospitalisation due to COVID-19 and recognised differences in study size, disease and location among individual studies, so additional methods to assess study-level RoB would be meaningful as Shi et al mentioned.
Third, we followed instructions4 5 to rate the quality of evidence in the GRADE approach, and two reviewers independently assigned the grade. We agree that the GRADE approach theoretically has a limitation to assess the quality of evidence for observational studies or incidence/prevalence studies because it includes few criteria to upgrade the quality of evidence for observational studies and has limited applicability to incidence/prevalence studies.6 Given that several previous studies have used the GRADE approach to assess the quality of evidence for meta-analysis in such settings,7–9 we think the GRADE approach would be a reasonable method if researchers are aware of the limitations.
Fourth, we showed that meta-analysis regarding each outcome had moderate to considerable heterogeneity (Figures 2, 3 and S5).2 Due to space limitation, we only described the GRADE assessment for the main outcomes, but we considered that the quality of evidence in other outcomes were ‘moderate’.
Fifth, we agree that a detailed presentation of the search strategy for each database is preferred whenever space permits. As for medRxiv, there were only six articles (6.7%) that originated from medRxiv search (Table S1).2 Thus, we do not think the heterogeneity was mainly attributed to preliminary works from medRxiv, but agree that performing sensitivity analysis for preprints is a good idea.
Sixth, our meta-analysis included studies from 15 different countries including China, Korea, France, Spain, Italy and USA (Table S1, Figure S2).2 We believe that this meta-analysis covers the global data of COVID-19 in patients with ADs, but we concur with Shi et al that publications in non-English language are often overlooked. Nevertheless, our systematic review was done at the end of July 2020, so updated evaluations regarding the prevalence and clinical outcomes of COVID-19 in patients with ADs are warranted.
Patient consent for publication
Handling editor Josef S Smolen
Contributors SA, SH, DM and AS: drafted the manuscript. SA and AS: critically reviewed the manuscript.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.
Provenance and peer review Commissioned; internally peer reviewed.