Study registration
This systematic review and network meta-analysis has been registered in the International Prospective Registry of Systematic Reviews (PROSPERO, CRD42023482572). The protocol followed the guidelines of the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocol statement [15]. The PRISMA-P checklist is provided in Supplementary Table 1. Any modifications to this protocol will be reported in our full reviews if needed.
Eligibility criteria
Types of studies
We will include RCTs, whether placebo-controlled or head-to-head trials, without restrictions on language or publication date. Non-randomized trials, observational studies, reviews, meta-analysis commentary articles, and studies with unavailable full text will be excluded.
Types of participants
We will include adults (aged ≥18 years) diagnosed with sepsis or septic shock[1,16,17] and exclude studies exclusively involving the elderly.
Types of interventions
We will include studies investigating the efficacy and safety of CTMs for treating sepsis or septic shock. The control groups received one of the following treatments: CTMs combined with western medicine (WM), a placebo combined with WM, or only WM. The experimental groups were treated with different types of CTMs combined with WM. WM includes antibiotics, fluid resuscitation, vasopressors, mechanical ventilation, and other necessary therapies [5,6,18–20]. CTMs are defined as medicines aimed at reinforcing the body and preventing diseases. We specified that CTMs should be administered orally or intravenously, with no restriction on dosage, frequency, or course of intervention.
Types of outcome measures
Primary outcomes
We chose the △SOFA score at day 7 after interventions and 28-day mortality as the primary outcomes. The △SOFA score is calculated by subtracting the SOFA score at enrollment from the corresponding value at day 7 after interventions.
Secondary outcomes
1. Delta serum lactate levels (△Lac) at day 7 after interventions.
2. Delta mean arterial pressure (△MAP) at day 7 after interventions.
3. Total dose and duration of vasoactive drugs.
Safety outcome
Adverse drug reactions or adverse drug events (ADRs/ADEs).
Search strategy
There were no restrictions on language or publication date. The Pubmed, Embase (via Ovid), Cochrane Central Register of Controlled Trials (via Ovid), Chinese Biomedical Literature Database (CBM), China National Knowledge Infrastructure (CNKI), Wanfang, and VIP database will be searched by two investigators (Rui Yang and Cheng Hu). We will search the following MeSH terms, keywords, abstracts or titles: “sepsis”, “septic shock”, “traditional Chinese medicine”, or “Chinese herbal medicine”. The detailed search strategies are provided in Supplementary Table 2.
Selection process
Zotero 6.0.23 software will be used to collect citations and remove duplicate articles. Two investigators (Rui Yang and Cheng Hu) will independently screen based on title and abstract first. The full text of all potentially relevant studies will be collected for subsequent assessment. In the presence of duplicate data, only studies with a larger sample size and longer follow-up time will be included. Any disagreements will be resolved by the third investigator (Lihui Deng). The process of study selection is shown in Supplementary figure 1.
Data collection process
Two investigators (Rui Yang and Cheng Hu) will independently extract the following data: study information (study design, first author name, publication year, study country), characteristics of participants (inclusion/exclusion criteria, size, age, sex), intervention and control (type of drug, administration, dose, frequency, and duration), outcomes (before and after the interventions). All the data will undergo cross-checking after extraction, and any disagreement will be resolved by the third investigator (Lihui Deng). In addition, we will send emails to researchers to obtain any missing data.
Assessment of risk of bias
The risk of bias for the included studies will be assessed by two investigators (Rui Yang and Cheng Hu) independently using the Cochrane Risk of Bias V.2.0. tool [21]. The assessments will be conducted across 5 domains: (1) bias arising from the randomization process, (2) bias due to deviations from intended interventions, (3) bias due to missing outcome data, (4) bias in the measurement of the outcome and (5) bias in the selection of reported result. Each domain will be classified as high, moderate (some concerns), or low risk of bias, and studies will be given an overall classification of high, moderate (some concerns) or low risk of bias. Any disagreements will be resolved with the third investigator (Lihui Deng).
Data synthesis and analysis
If quantitative analysis is feasible, R version 4.2.2 and STATA 15.0 software will be used for statistical analysis. In case quantitative analysis cannot be conducted, the results will be described narratively. For binary outcomes, the pooled effects will be calculated as risk ratio (RR) with 95% confidence intervals (CIs). For continuous outcomes, if the scales of outcomes are uniform, mean difference (MD) with 95% CIs will be used, otherwise, standardized mean difference (SMD) with 95% CIs will be applied. Median and interquartile ranges (IQRs) will be transformed to mean and standard deviation (SD) [22].
We will construct a Bayesian network meta-analysis for each outcome to compare the individual CTMs used for sepsis or septic shock patients using the “BUGSnet” (Bayesian inference Using Gibbs Sampling to conduct a Network meta-analysis) package[23] in R. Both fixed-effects and random-effects model will be fitted, and we will use the more suitable model. Model fit will be assessed using deviance information criterion (DIC) [24]. After selecting the appropriate model, we will evaluate model convergence using the trace and density plots, as well as Gelman-Rubin’s potential scale reduction factor [25]. The network plot will be created to visualize direct and indirect comparisons between different treatments. League tables will be generated to estimate relative effects of different treatments. Surface under the cumulative ranking curve (SUCRA) values will be utilized to rank each treatment [26]. A larger SUCRA value indicates a better rank of treatment.
Both global and local approaches will be used to assess inconsistency between direct and indirect evidence. We will use the Chi-square test to assess the global inconsistency. If closed loops exist, the node-splitting approach[27] will be used to examine the local inconsistency. Also, we will use a comparison-adjusted funnel plot to identify small study effects and assess potential publication bias in the outcomes with 10 or more RCTs. Heterogeneity will be assessed using the I 2. A sensitivity analysis will be performed to test the robustness of results by eliminating each study. If feasible, subgroup analysis will be performed for the primary outcomes based on the severity of the disease and the diagnostic criteria.
Certainty of Evidence Assessment
The quality of evidence for each outcome will be assessed using the CINeMA (Confidence in Network Meta-Analysis) web application [28,29]. The CINeMA includes 6 domains: (1) within-study bias, (2) across-studies bias, (3) indirectness, (4) imprecision, (5) heterogeneity and (6) incoherence. The certainty of evidence will be classified as high, moderate, low, or very low.