This study has applied for a registration number (CRD42020216330) on th e international prospective register of systematic reviews (PROSPERO: https://w ww.crd.york.ac.uk/PROSPERO/) database. This study will be conducted as per t he Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRIS MA-P) and the Cochrane Handbook for Systematic Review of interventions gui delines.
2.2 Eligibility criteria
2.2.1 Types of studies
Cohort, cross-sectional, case-control, randomized controlled, and non-randomized controlled studies published in Chinese or English will all be eligible for inclusion in the present analysis. Studies will be excluded if they are reviews, meta-analysis, editorials, case-reports, lack relevant data, have a study size < 10, or contain overlapping datasets.
2.2.2. Participant characteristics
Study participants must meet the following criteria: 1) Patients must have been diagnosed with COVID-19 as per appropriate clinical guidelines; 2) patients must have been found to have CKD prior to COVID-19 infection; 3) patients must be > 18 years old. Patients without COVID-19 will be excluded from this study.
2.2.3. Type of intervention
No disease interventions were defined for this study.
2.2.3. Types of outcomes
This first primary outcome will be the incidence of critical disease in analyzed patients, as defined by the occurrence of one of the following within two weeks following COVID-19 onset: 1) respiratory failure requiring manual ventilation; 2) shock; 3) combined organ failure necessitating admission to an intensive care unit (ICU). The goal of this outcome assessment will be to determine whether CKD is a risk factor for COVID-19.
The second primary outcome will be to determine whether CKD patients are more likely to suffer from COVID-19 infection. To that end, rates of COVID-19 infection among patients with and without CKD in the included studies will be compared based upon the results of reverse-transcription polymerase chain reaction (RT-PCR) tests for SARS-CoV-2 viral RNA.
Mortality in patients with CKD infected with COVID19.
2.3. Search strategy
Relevant articles published through November 2020 in the Wanfang, China Science Journal Citation Report (VIP database), EMBASE, CNKI, Web of Science, PubMed, and Cochrane Library databases will be incorporated into this meta-analysis. All searches will be repeated prior to the final analysis, and any relevant unpublished studies that can be identified will be incorporated as appropriate. Taking PubMed as an example, the retrieval strategy is shown in Table 1.
Studies will be screened independently by two reviewers, who will eliminate duplicate and irrelevant articles. When discrepancies arise between these two reviewers, a third investigator will be consulted (Fig. 1).
2.5. Data extraction
Data will be independently extracted from included studies by two investigators. Extracted data will include: author, year of publication, study location, study type, sample size, patient age, patient medical history, intervention time, treatment plan, and follow-up time, primary variables, and primary outcomes. Data will be compiled in a standardized spreadsheet, and discrepancies will be resolved through discussion.
2.6. Risk of bias assessment
Risk of bias for the included studies will be evaluated as per the guidelines of the Cochrane Manual 5.3.0. Seven dimensions will be assessed when gauging the risk of bias, including random sequence generation, allocation concealment, blinding protocols for patients, researchers, and outcomes assessors, incomplete outcome data, selective reporting, and other sources of bias. For each of these criteria, the risk of bias will be defined as low, high, or unclear.
2.7. Data analysis
Review Manager 5.3 will be used to conduct this meta-analysis. Dichotomous data will be given as odds ratios (ORs) and risk ratios (RRs), while continuous data will be determined using weighted mean deviations (WMDs) or standardized mean deviations (SMDS).
2.8. Assessment of heterogeneity
P-value and I2 statistics will be used to assess study heterogeneity, with significant heterogeneity being defined by P < 0.01 and I2 ≥ 50%. Fixed-effects and random-effects models will be used to analyze data when heterogeneity is not and is present, respectively.
2.9. Sensitivity analysis
Sensitivity analyses will be performed to confirm the stability of our findings, owing to the potential for differences in methodological quality among the included studies. Multiple tests will be performed as appropriate, and studies with a high risk of bias will be excluded in these analyses to evaluate their impact on overall study findings.
2.10. Reporting bias assessment
If more than 10 studies are included in our final analysis, funnel plots will be used to gauge the risk of reporting bias. When these plots appear asymmetric, we will endeavor to establish the reason for this outcome.