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Objectives To assess the reporting and methodological quality of COVID-19 systematic reviews, and to analyze trends and gaps in the quality, clinical topics, author countries, and populations of the reviews using an evidence mapping approach. Study Design and Setting A structured search for systematic reviews concerning COVID-19 was performed using PubMed, Embase, Cochrane Library, Campbell Library, Web of Science, CBM, WanFang Data, CNKI, and CQVIP from inception until June 2020. The quality of each review was assessed using the Assessment of Multiple Systematic Reviews 2 (AMSTAR 2) checklist and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. Results In total, 243 systematic reviews met the inclusion criteria, over 50% of which (128, 52.7%) were from 14 developing countries, with China contributing the most reviews (76, 31.3%). In terms of methodological quality of the studies, 30 (12.3%) were of moderate quality, 63 (25.9%) were of low quality, and 150 (61.7%) were of critically low quality. In terms of reporting quality, the median (interquartile range) PRISMA score was 14 (10–18). Regarding the topics of the reviews, 24 (9.9%) focused on the prevalence of COVID-19, 69 (28.4%) focused on the clinical manifestations, 30 (12.3%) focused on etiology, 43 (17.7%) focused on diagnosis, 65 (26.7%) focused on treatment, 104 (42.8%) focused on prognosis, and 25 (10.3%) focused on prevention. These studies mainly focused on general patients with COVID-19 (161, 66.3%), followed by children (22, 9.1%) and pregnant patients (18, 7.4%). Conclusion This study systematically evaluated the methodological and reporting quality of systematic reviews of COVID-19, summarizing and analyzing trends in their clinical topics, author countries, and study populations.

Background The coronavirus disease 2019 (COVID-19) pandemic continues to grow worldwide, and systematic reviews (SRs)/meta-analyses (MAs) on COVID-19 can efficiently guide evidence-based clinical practice. However, SRs/MAs with weaknesses can mislead clinical practice and pose harm to patients, and too many useless SRs/MAs could pose confusion and waste sources. A "living" overview of SRs/MAs aims to provide an open, accessible and frequently updated resource summarizing the highest-level evidence of COVID-19, that can help evidence-users to quickly identify trusted evidence to guide the practice. This study aims to systematically give an overview SRs/MAs of COVID-19, assess their quality, and identify the best synthesis of evidence. Methods Databases including Medline, EMBASE, Web of Science, China National Knowledge Infrastructure (CNKI), China Biology Medicine (CBM) and WanFang were systematically searched on May 1, 2020 using relevant terms for identify SRs/MAs related to COVID-19. The study selection, data extraction and quality assessment will be performed by independent reviewers, and results will be crosschecked. The authoritative tools (AMSTAR-2, PRISMA and its extensions) will be used to assess the methodological quality and reporting quality of included SRs/MAs, and potential influence factors will be explored. The consistency of conclusions will be compared among reviews and the best evidence will be summarized. In addition, we will conduct exploratory meta-analyses (MAs) of individual studies when applicable. Data will be reported as number with (or) percentage, risk ratio (RR) or odds ratio (OR), mean difference (MD) or standardized mean difference (SMD) with 95% confidence interval (CI) according to the specific results. R3.6.1 and Microsoft Excel 2016 will be used to analyze and manage data. Results The results of this overview will be submitted to a peer-reviewed journal for publication. Discussion In this study, we will present for the first time, an overview of SRs/MAs, which provides a comprehensive, dynamic evidence landscape on prevalence, prevention, diagnosis, treatment, and prognosis of COVID-19.

What is known and objective An increasing number of targeted drugs have been used to treat advanced or metastatic gastric cancer (GC) and gastroesophageal junction cancer (GEJC). However, the optimal treatment efficacy of these drugs is still controversial. The aims of this study are to systematically summarize the efficacy and safety of current targeted drugs for advanced or metastatic GC and GEJC. Methods PubMed, EmBase, Cochrane Library, Web of Science and ClinicalTrials were searched for double-blind randomized controlled trials (RCTs) on GC and GEJC up to December 2019. Additionally, we updated the literature search from Jan, 1, 2020 to September 30, 2021. Narrative and quantitative analysis were performed to analyse the efficacy and safety. STATA 15.1 was used to identify publication bias, and the SUCRA (surface under the cumulative ranking) curve was conducted to rank the treatments for each outcome. Results A total of 27 RCTs with 9295 GC and GEJC patients treated by 19 drugs were included. SUCRA showed that regorafenib was the most likely to improve patients' progression-free survival (96.4%), followed by apatinib (90.7%), nivolumab (82.4%), everolimus (76.5%) and pertuzumab (68.5%). Meanwhile, apatinib (92.4%) was most likely to improve overall survival, followed by nivolumab (87.9%), regorafenib (72.5%), olaparib (67.7%) and lapatinib (63.2%). Additionally, neutropenia, diarrhoea and fatigue were the most common adverse events caused by these drugs, followed by pain, nausea, decreased appetite, anaemia and vomiting. What is new and conclusion Regorafenib and nivolumab have higher efficacy and tolerability and are the most advantageous for advanced GC and GEJC. Moreover, apatinib has higher efficacy but lower tolerability. Everolimus and pertuzumab combined with chemotherapy have best secondary higher efficacy for progression-free survival and good tolerability. Lapatinib and olaparib combined with chemotherapy have moderate efficacy for overall survival and good tolerability.

Dignity is a vitally important aspect of the lives of advanced cancer patients. We conducted a systematic review and meta-analysis of the effectiveness of dignity therapy in this patient population.We searched for randomized controlled trials comparing dignity therapy versus standard care for patients with advanced cancer in five comprehensive databases (March 2019), two clinical trial registries and one gray literature database (August 2019). The quality of the studies was assessed using the risk of bias tool recommended by the Cochrane Handbook Version 5.1.0. We used GRADE approach to assess the certainty of evidence. Meta-analysis was performed with RevMan version 5.3. Outcomes of interest included anxiety, depression, dignity-related distress and quality of life (QoL).Ten trials evaluating 904 patients (control, 449; experimental, 455) were identified. Six trials included patients with different types of advanced cancer, and four trials included patients with a single advanced cancer (lung cancer [20%], breast cancer [10%], and hepatocellular carcinoma [10%]). Compared with the standard care, dignity therapy decreased the score of anxiety, depression, and dignity-related distress of the advanced cancer patients (SMD = -1.07, 95% CI: [-1.57, -0.58], p .05; SMD = -1.31, 95% CI: [-1.92, -0.70], p .05; MD = -7.30, 95% CI: [- 12.04, - 2.56], p .05). In addition, no significant differences were found in the patient's QoL (p .05).Very low certainty evidence demonstrated that dignity therapy might be a promising treatment, especially in reducing anxiety and depression in advanced cancer patients.

Objective: To evaluate the impact of the duration of breastfeeding on the intelligence of children. Materials and Methods: Eight electronic databases were searched to identify studies that investig...

Supplemental Digital Content is available in the text., Objectives: To compare different modalities of renal replacement therapy in critically ill adults with acute kidney injury. Data Sources: We searched Medline, PubMed, Embase, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov from inception to 25 May, 2020. We included randomized controlled trials comparing the efficacy and safety of different renal replacement therapy modalities in critically ill patients with acute kidney injury. Study Selection: Ten reviewers (working in pairs) independently screened studies for eligibility, extracted data, and assessed risk of bias. Data Extraction: We performed random-effects frequentist network meta-analyses and used the Grading of Recommendations, Assessment, Development, and Evaluation approach to assess certainty of evidence. The primary analysis was a four-node analysis: continuous renal replacement therapy, intermittent hemodialysis, slow efficiency extended dialysis, and peritoneal dialysis. The secondary analysis subdivided these four nodes into nine nodes including continuous veno-venous hemofiltration, continuous veno-venous hemodialysis, continuous veno-venous hemodiafiltration, continuous arterio-venous hemodiafiltration, intermittent hemodialysis, intermittent hemodialysis with hemofiltration, slow efficiency extended dialysis, slow efficiency extended dialysis with hemofiltration, and peritoneal dialysis. We set the minimal important difference threshold for mortality as 2.5% (relative difference, 0.04). Data Synthesis: Thirty randomized controlled trials (n = 3,774 patients) proved eligible. There may be no difference in mortality between continuous renal replacement therapy and intermittent hemodialysis (relative risk, 1.04; 95% CI, 0.93–1.18; low certainty), whereas continuous renal replacement therapy demonstrated a possible increase in mortality compared with slow efficiency extended dialysis (relative risk, 1.06; 95% CI, 0.85–1.33; low certainty) and peritoneal dialysis (relative risk, 1.16; 95% CI, 0.92–1.49; low certainty). Continuous renal replacement therapy may increase renal recovery compared with intermittent hemodialysis (relative risk, 1.15; 95% CI, 0.91–1.45; low certainty), whereas both continuous renal replacement therapy and intermittent hemodialysis may be worse for renal recovery compared with slow efficiency extended dialysis and peritoneal dialysis (low certainty). Peritoneal dialysis was probably associated with the shortest duration of renal support and length of ICU stay compared with other interventions (low certainty for most comparisons). Slow efficiency extended dialysis may be associated with shortest length of hospital stay (low or moderate certainty for all comparisons) and days of mechanical ventilation (low certainty for all comparisons) compared with other interventions. There was no difference between continuous renal replacement therapy and intermittent hemodialysis in terms of hypotension (relative risk, 0.92; 95% CI, 0.72–1.16; moderate certainty) or other complications of therapy, but an increased risk of hypotension and bleeding was seen with both modalities compared with peritoneal dialysis (low or moderate certainty). Complications of slow efficiency extended dialysis were not sufficiently reported to inform comparisons. Conclusions: The results of this network meta-analysis suggest there is no difference in mortality between continuous renal replacement therapy and intermittent hemodialysis although continuous renal replacement therapy may increases renal recovery compared with intermittent hemodialysis. Slow efficiency extended dialysis with hemofiltration may be the most effective intervention at reducing mortality. Peritoneal dialysis is associated with good efficacy, and the least number of complications however may not be practical in all settings. Importantly, all conclusions are based on very low to moderate certainty evidence, limited by imprecision. At the very least, ICU clinicians should feel comfortable that the differences between continuous renal replacement therapy, intermittent hemodialysis, slow efficiency extended dialysis, and, where clinically appropriate, peritoneal dialysis are likely small, and any of these modalities is a reasonable option to employ in critically ill patients.

Introduction Kidney transplant recipients are at increased susceptibility to many viral infections leading to justifiable anxiety about the effects of COVID-19. Methods We performed literature searches from multiple resources in April and August 2020 for relevant English and Chinese literature. Abstracts were screened, followed by full-text review with data extraction of reports that included at least 20 kidney transplant recipients with confirmed SARS-CoV-2 infection and completed outcomes. Results Twenty studies had sufficient data which we have summarised. Studies were predominantly descriptive and came from France, Italy, Spain, Turkey, UK, and USA. Quality assessment demonstrated limitations in selection of comparison groups and controlling for additional factors. Mortality rates from published studies were variable. Based on early data early from Spain, 46% of patients who developed COVID-19 within 60 days of transplantation died. Acute kidney injury was common, and mycophenolate was discontinued in most patients. Conclusion Given the rapid global spread of COVID-19, reliable evidence is needed to inform public health policies. Hospitalised kidney transplant recipients with COVID-19 are at a high risk of death in early reports but interpretation of this data requires caution as studies were susceptible to period effects. Reassuringly, the quality of observational data is improving. Detailed and comprehensive data collection through linked registries will be necessary to conduct accurate analyses of risk factors for adverse outcomes, not least given the risks of stopping immunosuppression. This report highlights the early mortality excess in transplant recipients but medium and longer-term outcomes remain uncertain and merit careful investigation., Graphical abstract

Background Several clinical trials investigated the effects of enteral lactoferrin supplementation on the prevention of sepsis and necrotizing enterocolitis (NEC) in preterm infants, but the efficacy and safety remain disputed. Therefore, we systematically evaluated the effect of enteral lactoferrin supplementation in preterm infants through a meta‑analysis with trial sequential analysis (TSA). Methods We searched six databases to identify randomized controlled trials (RCTs) that evaluated the effects of lactoferrin supplementation compared with placebo or no intervention in preterm infants. RevMan version 5.3 software was used to estimate pooled relative risks (RRs) with the random-effects model. TSA, subgroup analyses, and meta-regression analyses were also performed. Results Nine RCTs with 3515 samples were included. With low to moderate quality of evidence, compared with placebo, enteral lactoferrin supplementation did not significantly decrease the incidences of late-onset sepsis (RR = 0.63, 95% CI: 0.38 to 1.02, P = 0.06), NEC stage II or III (RR = 0.68, 95% CI: 0.30 to 1.52, P = 0.35), all-cause mortality (RR = 0.89, 95% CI: 0.51 to 1.57, P = 0.69), bronchopulmonary dysplasia (RR = 1.01, 95% CI: 0.90 to 1.13, P = 0.92), retinopathy of prematurity (RR = 0.80, 95% CI: 0.49 to 1.32, P = 0.38), invasive fungal infection (RR = 0.27, 95% CI: 0.02 to 3.94, P = 0.34), intraventricular hemorrhage (RR = 1.40, 95% CI: 0.39 to 5.08, P = 0.61), and urinary tract infection (RR = 0.35, 95% CI: 0.11 to 1.06, P = 0.06). Subgroup analysis revealed that lactoferrin significantly reduced the incidence of sepsis in infants with a birth weight below 1500 g (RR = 0.43, 95% CI: 0.22 to 0.84, P = 0.01). TSAs of the primary outcomes showed that the evidence is insufficient and further data is required. Conclusions Limited evidence suggested that enteral lactoferrin supplementation was associated with a reduction of late-onset sepsis in infants with a birth weight below 1500g, however, did not decrease the incidence of NEC stage II or III, all-cause mortality, and other adverse events in preterm infants. The present evidence was insufficient to inform clinical practice.

Objective To compare the effects of treatments for coronavirus disease 2019 (covid-19). Design Living systematic review and network meta-analysis. Data sources WHO covid-19 database, a comprehensive multilingual source of global covid-19 literature, up to 1 March 2021 and six additional Chinese databases up to 20 February 2021. Studies identified as of 12 February 2021 were included in the analysis. Study selection Randomised clinical trials in which people with suspected, probable, or confirmed covid-19 were randomised to drug treatment or to standard care or placebo. Pairs of reviewers independently screened potentially eligible articles. Methods After duplicate data abstraction, a bayesian network meta-analysis was conducted. Risk of bias of the included studies was assessed using a modification of the Cochrane risk of bias 2.0 tool, and the certainty of the evidence using the grading of recommendations assessment, development, and evaluation (GRADE) approach. For each outcome, interventions were classified in groups from the most to the least beneficial or harmful following GRADE guidance. Results 196 trials enrolling 76 767 patients were included; 111 (56.6%) trials and 35 098 (45.72%) patients are new from the previous iteration; 113 (57.7%) trials evaluating treatments with at least 100 patients or 20 events met the threshold for inclusion in the analyses. Compared with standard care, corticosteroids probably reduce death (risk difference 20 fewer per 1000 patients, 95% credible interval 36 fewer to 3 fewer, moderate certainty), mechanical ventilation (25 fewer per 1000, 44 fewer to 1 fewer, moderate certainty), and increase the number of days free from mechanical ventilation (2.6 more, 0.3 more to 5.0 more, moderate certainty). Interleukin-6 inhibitors probably reduce mechanical ventilation (30 fewer per 1000, 46 fewer to 10 fewer, moderate certainty) and may reduce length of hospital stay (4.3 days fewer, 8.1 fewer to 0.5 fewer, low certainty), but whether or not they reduce mortality is uncertain (15 fewer per 1000, 30 fewer to 6 more, low certainty). Janus kinase inhibitors may reduce mortality (50 fewer per 1000, 84 fewer to no difference, low certainty), mechanical ventilation (46 fewer per 1000, 74 fewer to 5 fewer, low certainty), and duration of mechanical ventilation (3.8 days fewer, 7.5 fewer to 0.1 fewer, moderate certainty). The impact of remdesivir on mortality and most other outcomes is uncertain. The effects of ivermectin were rated as very low certainty for all critical outcomes, including mortality. In patients with non-severe disease, colchicine may reduce mortality (78 fewer per 1000, 110 fewer to 9 fewer, low certainty) and mechanical ventilation (57 fewer per 1000, 90 fewer to 3 more, low certainty). Azithromycin, hydroxychloroquine, lopinavir-ritonavir, and interferon-beta do not appear to reduce risk of death or have an effect on any other patient-important outcome. The certainty in effects for all other interventions was low or very low. Conclusion Corticosteroids and interleukin-6 inhibitors probably confer important benefits in patients with severe covid-19. Janus kinase inhibitors appear to have promising benefits, but certainty is low. Azithromycin, hydroxychloroquine, lopinavir-ritonavir, and interferon-beta do not appear to have any important benefits. Whether or not remdesivir, ivermectin, and other drugs confer any patient-important benefit remains uncertain. Systematic review registration This review was not registered. The protocol is publicly available in the supplementary material. Readers’ note This article is a living systematic review that will be updated to reflect emerging evidence. Updates may occur for up to two years from the date of original publication. This is the fourth version of the original article published on 30 July 2020 ( BMJ 2020;370:m2980), and previous versions can be found as data supplements. When citing this paper please consider adding the version number and date of access for clarity.

Acupuncture is an alternative therapy for Parkinson's disease (PD), but its efficacy and safety are controversial. This overview aimed to summarize the existing evidence from systematic reviews (SRs) and meta-analyses (MAs) in order to assess the effectiveness of acupuncture as a treatment for PD.Seven electronic databases were searched from their inception until July 2019. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) and Assessment of Multiple Systematic Reviews 2 (AMSTAR2) checklists were used to assess evidence quality and methodological quality, respectively. The outcomes of study were calculated using mean differences (MDs) and risk ratios (RRs) with 95 % confidence intervals (CIs). A meta-analysis was performed using RevMan 5.3 software.A total of 12 SRs/MAs were included. All 12 SRs/MAs had more than one critical weakness in AMSTAR 2 and were considered of critically low methodological quality. The quality of evidence was unsatisfactory according to the GRADE checklist. Meta-analyses showed that acupuncture combined with drug for the treatment of PD can significantly improve the total effectiveness rate compared with drug alone (RR = 1.25, 95 % CI 1.16-1.34, P 0.001). It was also found that acupuncture combined with drug significantly improved the UPDRS I-IV total summed scores (WMD=-6.18, 95 % CI -10.32 to -2.04, P 0.001) and Webster scores (WMD=-4.20, 95 % CI -7.59 to -0.81, P 0.001).Acupuncture might improve the UPDRS score, Webster score, and total effective rate in treatment of PD. It might be a safe and useful adjunctive treatment for patients with PD. However, we should interpret the findings of these reviews with caution, considering the overall limited methodological and reporting quality.

Since the outbreak of coronavirus disease in 2019, the controversy over the effectiveness, safety, and enforceability of masks used by the public has been prominent. This study aims to identify, describe, and organize the currently available high-quality design evidence concerning mask use during the spread of respiratory viruses and find evidence gaps. Databases including PubMed, Cochrane Library, Web of Science, EMBASE, WHO International Clinical Trials Registry Platform (ICTRP), clinical trial registry, gray literature database, and reference lists of articles were searched for relevant randomized controlled trials (RCTs) and systematic reviews (SRs) in April 2020. The quality of the studies was assessed using the risk of bias tool recommended by the Cochrane Handbook Version 5.1.0 and the Assessment of Multiple Systematic Reviews (AMSTAR 2) tool. A bubble plot was designed to display information in four dimensions. Finally, twenty-one RCTs and nine SRs met our inclusion criteria. Most studies were of “Low quality” and focused on healthcare workers. Six RCTs reported adverse effects, with one implying that the cloth masks reuse may increase the infection risk. When comparing masks with usual practice, over 70% RCTs and also SRs showed that masks were “beneficial” or “probably beneficial”; however, when comparing N95 respirators with medical masks, 75% of SRs showed “no effect”, whereas 50% of RCTs showed “beneficial effect”. Overall, the current evidence provided by high-quality designs may be insufficient to deal with a second impact of the pandemic. Masks may be effective in interrupting or reducing the spread of respiratory viruses; however, the effect of an N95 respirator or cloth masks versus medical masks is unclear. Additional high-quality studies determining the impact of prolonged mask use on vulnerable populations (such as children and pregnant women), the possible adverse effects (such as skin allergies and shortness of breath) and optimal settings and exposure circumstances for populations to use masks are needed.

To assess the efficacy of electro-acupuncture (EA) relative to sham electro-acupuncture (sham EA) in treating chronic severe functional constipation (CSFC).A comprehensive search for relevant studies published between January 1, 1951 and May 14, 2020 was conducted in PubMed, the Cochrane Library, Chinese Biomedical Literature Database, Web of Science, and EMbase. Two investigators independently selected studies, extracted data, and assessed the quality of the included studies. The software Endnote X9 was used for screening articles, and the Review Manager 5.3 for analyzing data.The meta-analyses involved 6 studies and 1457 individuals. The pooled results favored the EA group for the increase of complete spontaneous bowel movements (CSBMs) per week in the fourth week (MD = 0.80, P = 0.001) during treatment, and further improved in the eight weeks (MD = 1.25, P0.001). During the follow-up period, significant changes in CSBMs per week were seen in the experimental group (MD = 1.38, P = 0.008); the effect decreased in the twelfth week (MD = 0.87, P0.001). There was no significant difference in the Bristol stool scale score between the two groups in the fourth week (MD = 0.40, P = 0.08), but significant differences were observed in the eighth week (MD = 0.40, P = 0.03). A significant reduction in patient assessment of constipation quality of life (PAC-QOL) score were observed in the EA group during treatment (SMD = -0.83, P0.001). No serious adverse events were reported.EA had favorable effects on CSFC, and the longer the treatment duration was, the better was the effect, but the effect showed a certain period of validity. However, the results may be influenced by the clinical heterogeneity of acupuncture points, depth of needling, intensity, and frequency of EA.

ObjectiveTo determine, in critically ill patients, the relative impact of proton pump inhibitors (PPIs), histamine-2 receptor antagonists (H2RAs), sucralfate, or no gastrointestinal bleeding prophylaxis (or stress ulcer prophylaxis) on outcomes important to patients.DesignSystematic review and network meta-analysis.Data sourcesMedline, PubMed, Embase, Cochrane Central Register of Controlled Trials, trial registers, and grey literature up to March 2019.Eligibility criteria for selecting studies and methodsWe included randomised controlled trials that compared gastrointestinal bleeding prophylaxis with PPIs, H2RAs, or sucralfate versus one another or placebo or no prophylaxis in adult critically ill patients. Two reviewers independently screened studies for eligibility, extracted data, and assessed risk of bias. A parallel guideline committee (BMJ Rapid Recommendation) provided critical oversight of the systematic review, including identifying outcomes important to patients. We performed random-effects pairwise and network meta-analyses and used GRADE to assess certainty of evidence for each outcome. When results differed between low risk and high risk of bias studies, we used the former as best estimates.ResultsSeventy two trials including 12 660 patients proved eligible. For patients at highest risk (>8%) or high risk (4-8%) of bleeding, both PPIs and H2RAs probably reduce clinically important gastrointestinal bleeding compared with placebo or no prophylaxis (odds ratio for PPIs 0.61 (95% confidence interval 0.42 to 0.89), 3.3% fewer for highest risk and 2.3% fewer for high risk patients, moderate certainty; odds ratio for H2RAs 0.46 (0.27 to 0.79), 4.6% fewer for highest risk and 3.1% fewer for high risk patients, moderate certainty). Both may increase the risk of pneumonia compared with no prophylaxis (odds ratio for PPIs 1.39 (0.98 to 2.10), 5.0% more, low certainty; odds ratio for H2RAs 1.26 (0.89 to 1.85), 3.4% more, low certainty). It is likely that neither affect mortality (PPIs 1.06 (0.90 to 1.28), 1.3% more, moderate certainty; H2RAs 0.96 (0.79 to 1.19), 0.9% fewer, moderate certainty). Otherwise, results provided no support for any affect on mortality, Clostridium difficile infection, length of intensive care stay, length of hospital stay, or duration of mechanical ventilation (varying certainty of evidence).ConclusionsFor higher risk critically ill patients, PPIs and H2RAs likely result in important reductions in gastrointestinal bleeding compared with no prophylaxis; for patients at low risk, the reduction in bleeding may be unimportant. Both PPIs and H2RAs may result in important increases in pneumonia. Variable quality evidence suggested no important effects of interventions on mortality or other in-hospital morbidity outcomes.Systematic review registrationPROSPERO CRD42019126656.

Background: Gastric cancer is the third leading cause of cancer death in the world. The benefit of adjuvant chemotherapy has been demonstrated by published individual patient data meta-analysis and Cochrane systematic review. However, there is no consensus on which is the optimal adjuvant chemotherapy regimens. Present network meta-analysis aims to compare the differences of effect between all available adjuvant chemotherapy regimens in improving overall survival and disease-free survival, and to rate the certainty of evidence from present network meta-analysis. Methods: We will conduct this systematic review and network meta-analysis using Bayesian method and according to Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) statement. We will search PubMed, EMBASE.com, the Cochrane Central Register of Controlled Trials (CENTRAL), Chinese National Knowledge Infrastructure (CNKI), and Chinese Biological Medical Database (CBM), and ClinicalTrials.gov (http://clinicaltrials.gov/) to identify randomized controlled trials (RCTs) comparing adjuvant chemotherapy to surgery alone. We will assess the risk of bias of individual RCTs using a modified version of Cochrane tool. We will also use the advance of GRADE to rate the certainty of network meta-analysis. Data analysis will be performed with R-3.4.1 and WinBUGS software. Results: The results of this study will be published in a peer-reviewed journal. Discussion: To the best of our knowledge, this systematic review and network meta-analysis will firstly use both direct and indirect evidence to compare the differences of all available adjuvant chemotherapy regimens for resected gastric cancer patients. This is a protocol of systematic review and meta-analysis, so the ethical approval and patient consent are not required.