Dataset Information

On evidence cycles in network meta-analysis.

ABSTRACT: As an extension of pairwise meta-analysis of two treatments, network meta-analysis has recently attracted many researchers in evidence-based medicine because it simultaneously synthesizes both direct and indirect evidence from multiple treatments and thus facilitates better decision making. The Bayesian hierarchical model is a popular method to implement network meta-analysis, and it is generally considered more powerful than conventional pairwise meta-analysis, leading to more precise effect estimates with narrower credible intervals. However, the improvement of effect estimates produced by Bayesian network meta-analysis has never been studied theoretically. This article shows that such improvement depends highly on evidence cycles in the treatment network. When all treatment comparisons are assumed to have different heterogeneity variances, a network meta-analysis produces posterior distributions identical to separate pairwise meta-analyses for treatment comparisons that are not contained in any evidence cycles. However, this equivalence does not hold under the commonly-used assumption of a common heterogeneity variance for all comparisons. Simulations and a case study are used to illustrate the equivalence of the Bayesian network and pairwise meta-analyses in certain networks.

SUBMITTER: Lin L

PROVIDER: S-EPMC7394478 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

On evidence cycles in network meta-analysis.

Lin Lifeng L Chu Haitao H Hodges James S JS

Statistics and its interface 20200101 4

As an extension of pairwise meta-analysis of two treatments, network meta-analysis has recently attracted many researchers in evidence-based medicine because it simultaneously synthesizes both direct and indirect evidence from multiple treatments and thus facilitates better decision making. The Bayesian hierarchical model is a popular method to implement network meta-analysis, and it is generally considered more powerful than conventional pairwise meta-analysis, leading to more precise effect es ...[more]

PMID: 32742550

Similar Datasets

Project description:BackgroundVarious luteal phase supports (LPSs) have been proven to increase the pregnancy rate in fresh cycles of in vitro fertilization or intracytoplasmic sperm injection; however, there is still significant debate regarding the optimal use of LPS.MethodsA systematic review with the use of a network meta-analysis was performed via electronic searching of Ovid MEDLINE, the Cochrane Library, Embase, Web of Science, ClinicalTrials.gov and Google Scholar (up to January 2021) to compare the effectiveness and safety of various LPSs, as well as to evaluate the effects of different initiations of LPSs on pregnancy outcomes. The primary outcomes included live birth and ongoing pregnancy, with the results presented as odds ratios (ORs) with 95% confidence intervals (CIs).ResultsEighty-nine randomized controlled trials with 29,625 women comparing 14 interventions or placebo/no LPS treatments were included in the meta-analyses. No significant differences were found in terms of the pregnancy outcomes when LPS was started within 48 h after oocyte retrieval versus a delayed initiation between 48 h and 96 h after oocyte retrieval. The addition of gonadotropin-releasing hormone (GnRH) agonists to progesterone vaginal pessaries showed a significant benefit in terms of live birth (OR 1.39, 95% CI 1.08 to 1.78). Only human chorionic gonadotropin (HCG) was found to be more efficacious than the placebo/no LPS treatment in terms of live birth (OR 15.43, 95% CI 2.03 to 117.12, low evidence). Any active LPSs (except for rectal or subcutaneous progesterone) was significantly more efficacious than the placebo/no LPS treatment in terms of ongoing pregnancy, with ORs ranging between 1.77 (95% CI 1.08 to 2.90) for the vaginal progesterone pessary and 2.14 (1.23 to 3.70) for the intramuscular progesterone treatment. Among the comparisons of efficacy and tolerability between the active treatments, the differences were small and very uncertain.ConclusionDelays in progesterone supplementation until 96 h after oocyte retrieval does not affect pregnancy outcomes. The safety of GnRH agonists during the luteal phase needs to be evaluated in future studies before the applications of these agonists in clinical practice. With comparable efficacy and acceptability, there may be several viable clinical options for LPS.

Project description:Preventing psychosis in patients at clinical high risk may be a promising avenue for pre-emptively ameliorating outcomes of the most severe psychiatric disorder. However, information on how each preventive intervention fares against other currently available treatment options remains unavailable. The aim of the current study was to quantify the consistency and magnitude of effects of specific preventive interventions for psychosis, comparing different treatments in a network meta-analysis. PsycINFO, Web of Science, Cochrane Central Register of Controlled Trials, and unpublished/grey literature were searched up to July 18, 2017, to identify randomized controlled trials conducted in individuals at clinical high risk for psychosis, comparing different types of intervention and reporting transition to psychosis. Two reviewers independently extracted data. Data were synthesized using network meta-analyses. The primary outcome was transition to psychosis at different time points and the secondary outcome was treatment acceptability (dropout due to any cause). Effect sizes were reported as odds ratios and 95% confidence intervals (CIs). Sixteen studies (2,035 patients, 57% male, mean age 20.1 years) reported on risk of transition. The treatments tested were needs-based interventions (NBI); omega-3?+?NBI; ziprasidone?+?NBI; olanzapine?+?NBI; aripiprazole?+?NBI; integrated psychological interventions; family therapy?+?NBI; D-serine?+?NBI; cognitive behavioural therapy, French & Morrison protocol (CBT-F)?+?NBI; CBT-F?+?risperidone?+?NBI; and cognitive behavioural therapy, van der Gaag protocol (CBT-V)?+?CBT-F?+?NBI. The network meta-analysis showed no evidence of significantly superior efficacy of any one intervention over the others at 6 and 12 months (insufficient data were available after 12 months). Similarly, there was no evidence for intervention differences in acceptability at either time point. Tests for inconsistency were non-significant and sensitivity analyses controlling for different clustering of interventions and biases did not materially affect the interpretation of the results. In summary, this study indicates that, to date, there is no evidence that any specific intervention is particularly effective over the others in preventing transition to psychosis. Further experimental research is needed.

Project description:BackgroundConducting systematic reviews is time-consuming but crucial to construct evidence-based patient decision aids, clinical practice guidelines and decision analyses. New methods might enable developers to produce a knowledge base more rapidly. However, trading off scientific rigour for speed when creating a knowledge base is controversial, and the consequences are insufficiently known. We developed and applied faster methods including systematic reviews and network meta-analyses, assessed their feasibility and compared them to a gold standard approach. We also assessed the feasibility of using decision analysis to perform this comparison.MethodsLong-term treatment in bipolar disorder was our testing field. We developed two new methods: an empirically based, rapid network meta-analysis (NMA) and an expert NMA, and conducted a patient survey. We applied these methods to collect effect estimates for evidence-based treatments on outcomes important to patients. The relative importance of outcomes was obtained from patients using a stated preference method. We used multi-criteria decision analysis to compare a gold standard NMA with the rapid NMA in terms of the ability of the gold standard NMA to change the ranking and expected values of treatments for individual patients.ResultsUsing rapid methods, it was feasible to identify evidence addressing outcomes important to patients. We found that replacing effect estimates from our rapid NMA with estimates from the gold standard NMA resulted in relatively small changes in the ranking and expected value of treatments. The rapid method sufficed to estimate the effects of nine out of ten options. To produce a ranking of treatments accurate for more than 95% of patients, it was necessary to supplement systematic with rapid methods and to use relative importance weights in the analysis. Integrating estimates of the outcome "treatment burden" had a larger impact on rankings than replacing rapid with gold standard methods. Using patients' importance weights only modestly affected results.ConclusionsThe transfer of knowledge to practice could benefit from faster systematic reviewing methods. The results in this preliminary assessment suggest that an improved rapid NMA approach might replace gold standard NMAs. Decision analysis could be used to compare evidence summarisation methods.

Project description:Background:The refractory/relapsed multiple myeloma (RRMM) remains a big clinical challenge, due to its biological and clinical complexity. Leading hematologists have performed many randomized controlled trials (RCTs) worldwide, and their findings were summarized in a recently published network meta-analysis (NMA) but with certain limitations. Materials and methods:We performed an updated NMA of RCTs related to RRMM treatment, focusing on efficacy measures including the nonresponse rate (NRR), time to progression (TTP), progression-free survival (PFS), and overall survival (OS). The PubMed database was searched. We extended the literature search strategy of a previous NMA to June 30, 2017 and included additional primary RCTs. The surface under the cumulative ranking curve (SUCRA) was calculated to rank the regimens. A weighted-average method was used to rank the regimens by summarizing SUCRAs across different outcome measures. Results:Finally, a total of 24 RCTs were included in this updated NMA. According to the result, the combination of daratumumab, lenalidomide, and dexamethasone showed better efficacy than other regimens in terms of NRR, TTP, and PFS (NRR: odds ratio [OR] =0.046, 95% credible interval [CrI] =[0.024, 0.085]; TTP: hazard ratio [HR] =0.14, 95% CrI =[0.092, 0.2]; PFS: HR =0.12, 95% CrI =[0.077, 0.18], compared with dexamethasone singlet). The combination of ixazomib, lenalidomide, and dexamethasone showed better efficacy than other regimens in terms of OS (HR =0.30, 95% CrI =[0.17, 0.54], compared with dexamethasone). The combination of daratumumab, lenalidomide, and dexamethasone ranked first in terms of overall efficacy (weighted average of SUCRAs =0.920). Conclusion:The combination of daratumumab, lenalidomide, and dexamethasone may currently be the most effective regimen in the population of RRMM patients. Triplet regimens containing daratumumab, ixazomib, carfilzomib, or elotumumab plus lenalidomide and dexamethasone can be recommended as first-line therapies for RRMM patients.

Dataset Information

On evidence cycles in network meta-analysis.

Publications

On evidence cycles in network meta-analysis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure