Network meta-analysis of multicomponent interventions

Interventions to prevent the onset of frailty in adults aged 60 and older (PRAE-Frail): a systematic review and network meta-analysis

PURPOSE

Frailty in older adults is associated with multiple adverse health outcomes, while evidence on its successful prevention has been scarce. Therefore, we analyzed the effectiveness of different interventions for the prevention of frailty onset.

METHODS

In this systematic review, eight databases were searched for randomized controlled trials of interventions in non-frail (i.e., robust or pre-frail) adults aged ≥ 60 years that assessed frailty incidence at follow-up. Additive component network meta-analysis (CNMA) was conducted to isolate the effect of different intervention types on the main outcome of frailty incidence, reporting relative risk (RR) with 95% confidence intervals (CI). The effect on gait speed was analyzed as an additional outcome using a classic network meta-analysis and the standardized mean difference (SMD) with 95% CI.

RESULTS

We screened 24,263 records and identified 11 eligible trials. Nine trials (842 participants, all categorized according to the physical phenotype) in pre-frail (seven RCTs) and robust/pre-frail (two RCTs) older adults were included in the CNMA. Physical exercise significantly reduced frailty incidence at follow-up (RR 0.26, 95% CI 0.08; 0.83), while this was not found for nutritional interventions (RR 1.16, 95% CI 0.33; 4.10). Interventions based on physical exercise also improved gait speed (SMD 1.55, 95% CI 1.16; 1.95). In addition, 22 eligible trial protocols without published results were identified.

CONCLUSION

Interventions based on physical exercise appear to be effective in preventing the onset of frailty in older adults. Although the available data are still limited, results from ongoing trials may add to the body of evidence in the foreseeable future.

Combining an Anterolateral Complex Procedure With Anterior Cruciate Ligament Reconstruction Reduces the Graft Reinjury Rate and Improves Clinical Outcomes: A Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND

Anterior cruciate ligament (ACL) reconstruction (ACLR) is a well-established surgical procedure, but it may not always restore complete rotational knee stability. Interest is increasing in anterolateral complex (ALC) procedures, lateral extra-articular tenodesis (LET) and anterolateral ligament reconstruction (ALLR), in association with ACLR to overcome this problem. The better ALC procedure, LET or ALLR, remains controversial to date.

PURPOSE

To analyze the patient-reported outcome measures and ACL reinjury rate after ACLR with an ALC procedure compared with after isolated ACLR, as well as to analyze the clinical results and graft failure rate of the LET group versus the ALLR group.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 2.

METHODS

A PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) flowchart was used to conduct a comprehensive search of 5 databases: Scopus, MEDLINE, Embase, PubMed, and the Cochrane Database of Systematic Reviews. Only randomized controlled trials were included. Eligible articles were classified according to the levels of evidence of the Oxford Centre for Evidence-Based Medicine. A methodological quality assessment of randomized controlled trials was performed using the Risk of Bias 2 tool. The present systematic review and meta-analysis was registered on PROSPERO.

RESULTS

A total of 14 clinical trials were included in the final analysis, with 1830 patients. Isolated ACLR or a combined procedure with LET or ALLR was performed, with several characteristics described, including the surgical technique, additional torn knee structures and their management, graft failure, complications, clinical outcomes, clinical and instrumental examinations to assess knee stability, and postoperative protocols. Regarding clinical outcomes, pivot-shift tests and reduced graft failure, a significant difference was found in the superiority of the combined ACLR associated with the ALC procedure compared with an isolated ACLR (P < .05). No statistically significant difference was found between the 2 ALC procedures.

CONCLUSION

This systematic review and meta-analysis reported on the importance of combined ACLR and ALC procedures in patients with a high-grade rotational laxity, as both procedures, LET or ALLR, without superiority of one over the other, are associated with improved pivot-shift tests, patient-reported outcome measures, and reduced graft failure rates.

Lipid lowering for prevention of venous thromboembolism: a network meta-analysis

BACKGROUND AND AIMS

Studies have suggested that statins may be associated with reduced risk of venous thromboembolism (VTE). The aim of the current study was to assess the evidence regarding the comparative effect of all lipid-lowering therapies (LLT) in primary VTE prevention.

METHODS

After a systematic search of PubMed, CENTRAL, and Web of Science up until 2 November 2022, randomized controlled trials (RCT) of statins (high- or low-/moderate-intensity), ezetimibe, or proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) were selected. An additive component network meta-analysis to compare VTE risk during long-term follow-up across different combinations of LLT was performed.

RESULTS

Forty-five RCTs (n = 254 933 patients) were identified, reporting a total of 2084 VTE events. Compared with placebo, the combination of PCSK9i with high-intensity statin was associated with the largest reduction in VTE risk (risk ratio [RR] 0.59; 95% confidence interval [CI] 0.43-0.80), while there was a trend towards reduction for high-intensity (0.84; 0.70-1.02) and low-/moderate-intensity (0.89; 0.79-1.00) statin monotherapy. Ezetimibe monotherapy did not affect the VTE risk (1.04; 0.83-1.30). There was a gradual increase in the summary effect of VTE reduction with increasing intensity of the LLT. When compared with low-/moderate-intensity statin monotherapy, the combination of PCSK9i and high-intensity statin was significantly more likely to reduce VTE risk (0.66; 0.49-0.89).

CONCLUSIONS

The present meta-analysis of RCTs suggests that LLT may have a potential for VTE prevention, particularly in high-intensity dosing and in combination therapy.

Non-pharmacological interventions for improving language and communication in people with primary progressive aphasia

BACKGROUND

Primary progressive aphasia (PPA) accounts for approximately 43% of frontotemporal dementias and is mainly characterised by a progressive impairment of speech and communication abilities. Three clinical variants have been identified: (a) non-fluent/agrammatic, (b) semantic, and (c) logopenic/phonological PPA variants. There is currently no curative treatment for PPA, and the disease progresses inexorably over time, with devastating effects on speech and communication ability, functional status, and quality of life. Several non-pharmacological interventions that may improve symptoms (e.g. different forms of language training and non-invasive brain stimulation) have been investigated in people with PPA.

OBJECTIVES

To assess the effects of non-pharmacological interventions for people with PPA on word retrieval (our primary outcome), global language functions, cognition, quality of life, and adverse events.

SEARCH METHODS

We searched the Cochrane Dementia and Cognitive Improvement Group's trial register, MEDLINE (Ovid SP), Embase (Ovid SP), four other databases and two other trial registers. The latest searches were run on 26 January 2024.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) evaluating the effects of non-pharmacological interventions in people with PPA.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

There were insufficient data available to conduct the network meta-analyses that we had originally planned (due to trial data being insufficiently reported or not reported at all, as well as the heterogeneous content of the included interventions). Therefore, we provide a descriptive summary of the included studies and results. We included 10 studies, with a total of 132 participants, evaluating non-pharmacological interventions. These were: transcranial direct current stimulation (tDCS) or repetitive transcranial magnetic stimulation (rTMS) as stand-alone treatments (used by two and one studies, respectively); tDCS combined with semantic and phonological word-retrieval training (five studies); tDCS combined with semantic word-retrieval training (one study); and tDCS combined with phonological word-retrieval training (one study). Results for our primary outcome of word retrieval were mixed. For the two studies that investigated the effects of tDCS as stand-alone treatment compared to placebo ("sham") tDCS, we rated the results as having very low-certainty evidence. One study found a significant beneficial effect on word retrieval after active tDCS; one study did not report any significant effects in favour of the active tDCS group. Five studies investigated tDCS administered to the dorsolateral prefrontal cortex, inferior frontal cortex, left frontotemporal region, or the temporoparietal cortex, combined with semantic and phonological word-retrieval training. The most consistent finding was enhancement of word-retrieval ability for trained items immediately after the intervention, when behavioural training was combined with active tDCS compared to behavioural training plus sham tDCS. We found mixed effects for untrained items and maintenance of treatment effects during follow-up assessments. We rated the certainty of the evidence as very low in all studies. One study investigated tDCS combined with semantic word-retrieval training. Training was provided across 15 sessions with a frequency of three to five sessions per week, depending on the personal preferences of the participants. tDCS targeted the left frontotemporal region. The study included three participants: two received 1 mA stimulation and one received 2 mA stimulation. The study showed mixed results. We rated it as very low-certainty evidence. One study investigated tDCS combined with phonological word-retrieval training. Training was again provided across 15 sessions over a period of three weeks. tDCS targeted the left inferior frontal gyrus. This study showed a significantly more pronounced improvement for trained and untrained words in favour of the group that had received active tDCS, but we rated the certainty of the evidence as very low. One study compared active rTMS applied to an individually determined target site to active rTMS applied to a control site (vertex) for effects on participants' word retrieval. This study demonstrated better word retrieval for active rTMS administered to individually determined target brain regions than in the control intervention, but we rated the results as having a very low certainty of evidence. Four studies assessed overall language ability, three studies assessed cognition, five studies assessed potential adverse effects of brain stimulation, and one study investigated quality of life.

AUTHORS' CONCLUSIONS

There is currently no high-certainty evidence to inform clinical decision-making regarding non-pharmacological treatment selection for people with PPA. Preliminary evidence suggests that the combination of active tDCS with specific language therapy may improve impaired word retrieval for specifically trained items beyond the effects of behavioural treatment alone. However, more research is needed, including high-quality RCTs with detailed descriptions of participants and methods, and consideration of outcomes such as quality of life, depressive symptoms, and overall cognitive functioning. Moreover, studies assessing optimal treatments (i.e. behavioural interventions, brain stimulation interventions, and their combinations) for individual patients and PPA subtypes are needed. We were not able to conduct the planned (network) meta-analyses due to missing data that could not be obtained from most of the authors, a general lack of RCTs in the field, and heterogeneous interventions in eligible trials. Journals should implement a mandatory data-sharing requirement to assure transparency and accessibility of data from clinical trials.

Assessing the relative effectiveness of various ultrasound-guided ablation techniques for treating benign thyroid nodules: A systematic review and network meta-analysis

BACKGROUND

Benign thyroid nodules (BTNs) represent a prevalent clinical challenge globally, with various ultrasound-guided ablation techniques developed for their management. Despite the availability of these methods, a comprehensive evaluation to identify the most effective technique remains absent. This study endeavors to bridge this knowledge gap through a network meta-analysis (NMA), aiming to enhance the understanding of the comparative effectiveness of different ultrasound-guided ablation methods in treating BTNs.

METHODS

We comprehensively searched PubMed, Embase, Cochrane, Web of Science, Ovid, SCOPUS, and ProQuest for studies involving 16 ablation methods, control groups, and head-to-head trials. NMA was utilized to evaluate methods based on the percentage change in nodule volume, symptom score, and cosmetic score. This study is registered in INPLASY (registration number 202260061).

RESULTS

Among 35 eligible studies involving 5655 patients, NMA indicated that RFA2 (radiofrequency ablation, 2 sessions) exhibited the best outcomes at 6 months for percentage change in BTN volume (SUCRA value 74.6), closely followed by RFA (SUCRA value 73.7). At 12 months, RFA was identified as the most effective (SUCRA value 81.3). Subgroup analysis showed RFA2 as the most effective for solid nodule volume reduction at 6 months (SUCRA value 75.6), and polidocanol ablation for cystic nodules (SUCRA value 66.5).

CONCLUSION

Various ablation methods are effective in treating BTNs, with RFA showing notable advantages. RFA with 2 sessions is particularly optimal for solid BTNs, while polidocanol ablation stands out for cystic nodules.

When does the placebo effect have an impact on network meta-analysis results?

The placebo effect is the 'effect of the simulation of treatment that occurs due to a participant's belief or expectation that a treatment is effective'. Although the effect might be of little importance for some conditions, it can have a great role in others, mostly when the evaluated symptoms are subjective. Several characteristics that include informed consent, number of arms in a study, the occurrence of adverse events and quality of blinding may influence response to placebo and possibly bias the results of randomised controlled trials. Such a bias is inherited in systematic reviews of evidence and their quantitative components, pairwise meta-analysis (when two treatments are compared) and network meta-analysis (when more than two treatments are compared). In this paper, we aim to provide red flags as to when a placebo effect is likely to bias pairwise and network meta-analysis treatment effects. The classic paradigm has been that placebo-controlled randomised trials are focused on estimating the treatment effect. However, the magnitude of placebo effect itself may also in some instances be of interest and has also lately received attention. We use component network meta-analysis to estimate placebo effects. We apply these methods to a published network meta-analysis, examining the relative effectiveness of four psychotherapies and four control treatments for depression in 123 studies.

Evidence Synthesis for Complex Interventions Using Meta-Regression Models

A goal of evidence synthesis for trials of complex interventions is to inform the design or implementation of novel versions of complex interventions by predicting expected outcomes with each intervention version. Conventional aggregate data meta-analyses of studies comparing complex interventions have limited ability to provide such information. We argue that evidence synthesis for trials of complex interventions should forgo aspirations of estimating causal effects and instead model the response surface of study results to 1) summarize the available evidence and 2) predict the average outcomes of future studies or in new settings. We illustrate this modeling approach using data from a systematic review of diabetes quality improvement (QI) interventions involving at least 1 of 12 QI strategy components. We specify a series of meta-regression models to assess the association of specific components with the posttreatment outcome mean and compare the results to conventional meta-analysis approaches. Compared with conventional approaches, modeling the response surface of study results can better reflect the associations between intervention components and study characteristics with the posttreatment outcome mean. Modeling study results using a response surface approach offers a useful and feasible goal for evidence synthesis of complex interventions that rely on aggregate data.

School-based interventions TO Prevent Dating and Relationship Violence and Gender-Based Violence: STOP-DRV-GBV systematic review

Background

Schools have a duty of care to prevent violence between students but a significant amount of dating and relationship violence and gender-based violence occurs in schools. These are important public health issues with important longitudinal consequences for young people.

Objectives

To understand functioning and effectiveness of school-based interventions for the prevention of dating and relationship violence and gender-based violence.

Review methods

We undertook a mixed-methods systematic review to synthesise different types of evidence relating to school-based interventions for the prevention of dating and relationship violence and gender-based violence to understand if, how and in what ways these interventions are effective. We searched 21 databases and 2 trial registers and undertook forwards and backwards citation chasing, author contact and other supplementary search methods. Searches identified all literature published to June 2021. All screening was undertaken in duplicate and independently, and we quality appraised all included studies.

Results

We included 247 reports (68 outcome evaluations, 137 process evaluations). Synthesis of intervention components produced an intervention typology: single-component, curricular, multicomponent, and multilevel programmes. Synthesis of intervention theories suggested that interventions aiming to increase students' sense of school belonging and sense of safety in the school building could encourage increased learning of prosocial skills and increased prosocial peer norms, and so potentially reducing dating and relationship violence and gender-based violence. Synthesis of factors affecting delivery highlighted school organisation and leaders who believed in the importance of addressing dating and relationship violence/gender-based violence, along with time and resources to deliver the interventions. The ease with which the intervention could be delivered and modified was also important. Meta-analysis found stronger evidence for intervention effectiveness in reducing dating and relationship violence than for gender-based violence, with significant long-term impacts on dating and relationship violence victimisation and perpetration, and some evidence that interventions in high-income countries could be effective for reducing victimisation and perpetration of gender-based violence in the long-term. Impacts on knowledge and attitudes were primarily short-term. Network meta-analysis did not suggest superiority of any intervention type. Moderation evidence suggested interventions reduced dating and relationship violence perpetration in boys more than girls, but reduced gender-based violence perpetration more in girls. Metaregression by intervention component did not explain heterogeneity in effectiveness, but qualitative comparative analysis suggested that reducing perpetration was important to reducing victimisation, and that perpetration could be reduced via focus on interpersonal skills, guided practice and (for gender-based violence) implementation of social structural components.

Limitations

Despite an exhaustive search, trials may have been missed and risk of publication bias was high for several analyses.

Conclusions

This is the most comprehensive systematic review of school-based interventions for dating and relationship violence and gender-based violence to date. It is clear that the prevention of dating and relationship violence and gender-based violence in schools will require longer-term investment to show benefit.

Future work

Future research is needed to understand why intervention effectiveness appears stronger for dating and relationship violence than gender-based violence.

Study registration

The study is registered as PROSPERO CRD42020190463.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Public Health Research programme (NIHR award ref: NIHR130144) and is published in full in Public Health Research; Vol. 12, No. 3. See the NIHR Funding and Awards website for further award information.

Twenty years of network meta-analysis: Continuing controversies and recent developments

Network meta-analysis (NMA) is an extension of pairwise meta-analysis (PMA) which combines evidence from trials on multiple treatments in connected networks. NMA delivers internally consistent estimates of relative treatment efficacy, needed for rational decision making. Over its first 20 years NMA's use has grown exponentially, with applications in both health technology assessment (HTA), primarily re-imbursement decisions and clinical guideline development, and clinical research publications. This has been a period of transition in meta-analysis, first from its roots in educational and social psychology, where large heterogeneous datasets could be explored to find effect modifiers, to smaller pairwise meta-analyses in clinical medicine on average with less than six studies. This has been followed by narrowly-focused estimation of the effects of specific treatments at specific doses in specific populations in sparse networks, where direct comparisons are unavailable or informed by only one or two studies. NMA is a powerful and well-established technique but, in spite of the exponential increase in applications, doubts about the reliability and validity of NMA persist. Here we outline the continuing controversies, and review some recent developments. We suggest that heterogeneity should be minimized, as it poses a threat to the reliability of NMA which has not been fully appreciated, perhaps because it has not been seen as a problem in PMA. More research is needed on the extent of heterogeneity and inconsistency in datasets used for decision making, on formal methods for making recommendations based on NMA, and on the further development of multi-level network meta-regression.

Effectiveness of sound and darkness interventions for critically ill patients' sleep quality: A systematic review and component network meta-analysis

BACKGROUND

Noise and lighting are prime factors of poor sleep quality in critically ill patients, which impair recovery and increase the risk of delirium or complications.

AIM

To identify and rank the effectiveness of sound and darkness interventions on the sleep quality of critically ill patients.

STUDY DESIGN

This systematic review and component network meta-analysis was based on the Preferred Reporting Items for Systematic Reviews incorporating the Network Meta-Analyses (PRISMA-NMA) Statement. The Embase, MEDLINE, Cochrane CENTRAL, CINAHL, Airiti Library, and Google Scholar databases were searched from inception to August 10, 2021, for randomized controlled trials (RCTs) on sound and darkness interventions targeting critically ill patients' sleep quality. We applied standard and component NMA to determine the effects of interventions. The certainty of evidence was evaluated using the Cochrane risk-of-bias tool (V.2.0) and the online Confidence in Network Meta-Analysis (CINeMA) application.

RESULTS

Twenty-four RCTs with 1507 participants who used combined interventions constituting seven competing interventions were included in the standard NMA. The combination of earplugs, eye masks, and music; eye masks alone; earplugs combined with eye masks; and music alone had beneficial intervention effects. The combination of earplugs, eye masks, and music was the best intervention, and these components had no interaction effect. An eye mask had the best relative effect, followed by music, quiet time, and earplugs.

CONCLUSIONS

This study provides clinical evidence of the effectiveness of using eye masks, music, and earplugs to improve sleep quality in critically ill patients. We also recommend future research using bedtime music, nocturnal eye masks, and quiet time, which had the best relative effects on sleep quality.

RELEVANCE TO CLINICAL PRACTICE

This study provides recommendations for interventions that nurses can use to improve critically ill patients' sleep quality.

The efficacy and adverse events of arsenic trioxide for the patients with myelodysplastic syndrome: a systematic review and component network meta-analysis

BACKGROUND

Arsenic trioxide (ATO) might be effective for myelodysplastic syndrome (MDS) by apoptosis induction and demethylation. But ATO has not been widely recommended for small sample and conflicting conclusion of existing trials. This review aimed to systematically evaluate the efficacy of regimens containing ATO for the MDS and explore optimal combination.

METHOD

Randomized clinical trials (RCTs) about ATO regimens were retrieved from China National Knowledge Infrastructure, Embase and PubMed. With odds ratio (OR) as the effect size, network meta-analysis (NMA) and component network meta-analysis (CNMA) were conducted by R and 'netmeta' package, after study selection, quality assessment and data extraction.

RESULT

Thirty-night RCTs were included with a total of 2125 patients, including 1235 treated by ATO containing regimen. With support therapy alone as reference, no inconsistency and heterogeneity were observed. Although NMA did not demonstrate better efficacy of ATO alone, the result of CNMA indicated that ATO was effective in the improvement of overall remission (ORR) [OR = 2.09(1.61, 2.71)] and complete remission (CR) [OR  = 1.66(1.25, 2.21)]. Five ATO-containing regimens reported could effectively improve ORR, some of them benefit in CR or hematological improvement (HI) as well. ATO + Traditional Chinese Medicine (TCM), ATO + Thalidomide (T)+TCM, ATO + Chemotherapy (Chem)+T + TCM were regarded as the optimal combination, which improved both ORR, CR and HI in theory. ATO did not increase the risk of common adverse events compared to supportive therapy [(OR = 0.90(0.67, 1.21)].

CONCLUSION

ATO may be an effective and well-tolerant option for patients with myelodysplastic syndrome.

Effect of exercise intervention on depression in children and adolescents: A systematic review and network meta-analysis

OBJECTIVES

To evaluate the effect of different exercise interventions on depressive symptoms in children and adolescents.

METHODS

Randomized controlled trials (RCT) published until May 2023 were screened in four databases. The Cochrane collaboration tool was used to assess the risk of bias for quality evaluation. Stata 16.0 software was used for both a pairwise meta-analysis and a series of frequentist network meta-analyses (NMA).

RESULTS

A total of 35 RCTs and 5393 participants were included. Aerobic exercise had the most significant effect on depressive symptoms (66.2 %), followed by group training (62.5 %), resistance exercise (59.0 %), and aerobic combined with resistance exercise (57.9 %). Furthermore, children and adolescents younger than 15 years showed significant improvement in depressive symptoms (SMD = -0.41, 95 % CI (-0.63, -0.19), P < 0.01). The study also found a significant improvement in depression among healthy, obesity, and depressed populations (SMD = -0.25, 95 % CI (-0.41, -0.08), P < 0.01); SMD = -0.15, 95 % CI (-0.31, -0.00), P < 0.01; SMD = -0.75, 95 % CI (-1.32, -0.19), P < 0.01). Additionally, 30 min of exercise had a significant effect (SMD = -0.14, 95 % CI (-0,81, -0.01), P < 0.01), and 40-50 min of exercise had the best effect (SMD = -0.17, 95 % CI (-0,33, -0.02), P < 0.01). Lastly, exercise frequency of three times per week was significant in children and adolescents (SMD = -0.42, 95 % CI (-0,66, -0.18), P < 0.01).

CONCLUSION

Exercise significantly improves depressive symptoms in children and adolescents, with aerobic exercise having the most significant effect. A 12-week, three-times-a-week, 40-50-min exercise intervention was found to be more effective in younger children and adolescents.

Data visualisation approaches for component network meta-analysis: visualising the data structure

BACKGROUND

Health and social care interventions are often complex and can be decomposed into multiple components. Multicomponent interventions are often evaluated in randomised controlled trials. Across trials, interventions often have components in common which are given alongside other components which differ across trials. Multicomponent interventions can be synthesised using component NMA (CNMA). CNMA is limited by the structure of the available evidence, but it is not always straightforward to visualise such complex evidence networks. The aim of this paper is to develop tools to visualise the structure of complex evidence networks to support CNMA.

METHODS

We performed a citation review of two key CNMA methods papers to identify existing published CNMA analyses and reviewed how they graphically represent intervention complexity and comparisons across trials. Building on identified shortcomings of existing visualisation approaches, we propose three approaches to standardise visualising the data structure and/or availability of data: CNMA-UpSet plot, CNMA heat map, CNMA-circle plot. We use a motivating example to illustrate these plots.

RESULTS

We identified 34 articles reporting CNMAs. A network diagram was the most common plot type used to visualise the data structure for CNMA (26/34 papers), but was unable to express the complex data structures and large number of components and potential combinations of components associated with CNMA. Therefore, we focused visualisation development around representing the data structure of a CNMA more completely. The CNMA-UpSet plot presents arm-level data and is suitable for networks with large numbers of components or combinations of components. Heat maps can be utilised to inform decisions about which pairwise interactions to consider for inclusion in a CNMA model. The CNMA-circle plot visualises the combinations of components which differ between trial arms and offers flexibility in presenting additional information such as the number of patients experiencing the outcome of interest in each arm.

CONCLUSIONS

As CNMA becomes more widely used for the evaluation of multicomponent interventions, the novel CNMA-specific visualisations presented in this paper, which improve on the limitations of existing visualisations, will be important to aid understanding of the complex data structure and facilitate interpretation of the CNMA results.

Adherence enhancing interventions for pharmacological and oxygen therapy in patients with COPD: protocol for a systematic review and component network meta-analyses

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is characterised by hyperinflation and expiratory airflow limitation due to long-term exposure to irritants. The variety and complexity of COPD treatment and the possible added comorbidities may make the patients find it difficult to cope with the required medications. That is why supporting patients' adherence is critical because not taking medications correctly increases the risk of complications and creates an additional financial burden. A range of interventions aiming to improve patient adherence were used, and most of them are complex since they involve a mix of elements. Furthermore, despite the variety of available tools, assessing adherence is challenging because clinicians usually do not get a concrete judgement if their patients followed their treatment plan reliably. We aim to evaluate the effectiveness of adherence-enhancing interventions for COPD patients, explore which intervention (component) works for which patients and check the factors influencing the implementation and participant responses.

METHODS

We will perform a comprehensive literature search (Medline, Embase, Cochrane Library, trial registries) without restrictions on language and publication status, and we will include all controlled studies investigating the effect of adherence-enhancing intervention on patients with COPD. We plan to involve COPD patients in the systematic review development through two patient interviews (one before and one after the systematic review). Two reviewers will perform the screening, data extraction and risk of bias (ROB) assessment. For ROB, we will use ROB 2.0 to assess randomised controlled trials, and ROBINS-I to assess non-randomised studies. We will perform pair-wise random-effects meta-analyses and component network meta-analyses to identify the most effective components and combinations of components. We will use the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach to assess the quality of evidence. To determine the degree of complexity, we will use the iCAT_SR checklist, and then, following a logical model, we will group the interventions according to prespecified criteria.

DISCUSSION

This systematic review aims to point out the most effective and implementable adherence-enhancing interventions by using methods for synthesising evidence on complex interventions and involving COPD patients all along with the review process.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022353977.

Effect modification in network meta-analyses for relapsed/refractory multiple myeloma: systematic review and meta-analysis

OBJECTIVES

To systematically review and meta-analyse the evidence for effect modification by refractory status and number of treatment lines in relapsed/refractory multiple myeloma (RRMM); and to assess whether effect modification is likely to invalidate network meta-analyses (NMA) that assume negligible modification.

DESIGN

Systematic review, meta-analysis and simulation.

DATA SOURCES

We systematically searched the literature (e.g., OVID Medline) to identify eligible publications in February 2020 and regularly updated the search until January 2022. We also contacted project stakeholders (including industry) ELIGIBILITY CRITERIA: Phase 2 and 3 randomised controlled trials reporting stratified estimates for comparisons with at least one of a prespecified set of treatments relevant for use in Norwegian RRMM patients.

OUTCOMES

We used meta-analysis to estimate relative HRs (RHRs) for overall survival (OS) and progression-free survival (PFS) with respect to refractory status and number of treatment lines. We used the estimated RHRs in simulations to estimate the percentage of NMA results expected to differ significantly in the presence versus absence of effect modification.

RESULTS

Among the 42 included publications, stratified estimates were published by and extracted from up to 18 (43%) publications and on as many as 8364 patients. Within-study evidence for effect modification is very weak (p>0.05 for 47 of 49 sets of stratified estimates). The largest RHR estimated was 1.32 (95% CI 1.18 to 1.49) for the modifying effect of refractory status on HR for PFS. Simulations suggest that, in the worst case, this would result in only 4.48% (95% CI 4.42% to 4.54%) of NMA estimates differing statistically significantly in the presence versus absence of effect modification.

CONCLUSIONS

Based on the available evidence, effect modification appears to be sufficiently small that it can be neglected in adequately performed NMAs. NMAs can probably be relied on to provide estimates of HRs for OS and PFS in RRMM, subject to caveats discussed herein.

Effects of Physical Activity Interventions on Strength, Balance and Falls in Middle-Aged Adults: A Systematic Review and Meta-Analysis

BACKGROUND

Weak lower body strength and balance impairments are fundamental risk factors for mobility impairments and falls that can be improved by physical activity (PA). Previous meta-analyses have focused on these risk factors in adults aged ≥ 65 years. Yet, the potential of PA for improving these risk factors in middle-aged populations has not been systematically investigated. This systematic review and meta-analysis aim to examine the effect of general and structured PA on lower limb strength, postural balance and falls in middle-aged adults.

METHODS

A computerized systematic literature search was conducted in the electronic databases MEDLINE, CINAHL, Web of Science and Cochrane Library. PA intervention types were classified according to the ProFaNE taxonomy. Randomized controlled trials exploring the effects of PA on strength (e.g., leg press one-repetition-maximum), balance (e.g., single limb stance) and falls (e.g., fall rates) in adults aged 40-60 years were systematically searched and included in a network analysis. Moderator analyses were performed for specific subgroups (age, sex, low PA). The methodological quality of the included studies was assessed using the Physiotherapy Evidence Database (PEDro) Scale.

RESULTS

Out of 7170 articles screened, 66 studies (median PEDro score 5) with 3387 participants were included. Strong, significant effects on muscle strength were found for strength (SMD = 1.02), strength-aerobic (SMD = 1.41), strength-endurance (SMD = 0.92) and water-based (SMD = 1.08) training (52 studies, I² = 79.3%). Strength training (SMD = 1.16), strength-aerobic (SMD = 0.98) and 3D training (SMD = 1.31) improved postural balance (30 studies, I² = 88.1%). Moderator analyses revealed significant effects of specific intervention types on certain subgroups and subdomains of strength and balance. No studies were found measuring falls.

CONCLUSIONS

Structured PA interventions in middle-aged adults improve strength and balance outcomes related to functional impairments and falls. Strength training increases both strength and balance and can be recommended to prevent age-related functional decline. However, the interpretability of the results is limited due to considerable heterogeneity and the overall low methodological quality of the included studies. Long-term trials are needed to determine the preventive potential of PA on strength, balance and falls. This meta-analysis may inform guidelines for tailored training during middle age to promote healthy aging. Prospero registration: CRD42020218643.

Model selection for component network meta-analysis in connected and disconnected networks: a simulation study

BACKGROUND

Network meta-analysis (NMA) allows estimating and ranking the effects of several interventions for a clinical condition. Component network meta-analysis (CNMA) is an extension of NMA which considers the individual components of multicomponent interventions. CNMA allows to "reconnect" a disconnected network with common components in subnetworks. An additive CNMA assumes that component effects are additive. This assumption can be relaxed by including interaction terms in the CNMA.

METHODS

We evaluate a forward model selection strategy for component network meta-analysis to relax the additivity assumption that can be used in connected or disconnected networks. In addition, we describe a procedure to create disconnected networks in order to evaluate the properties of the model selection in connected and disconnected networks. We apply the methods to simulated data and a Cochrane review on interventions for postoperative nausea and vomiting in adults after general anaesthesia. Model performance is compared using average mean squared errors and coverage probabilities.

RESULTS

CNMA models provide good performance for connected networks and can be an alternative to standard NMA if additivity holds. For disconnected networks, we recommend to use additive CNMA only if strong clinical arguments for additivity exist.

CONCLUSIONS

CNMA methods are feasible for connected networks but questionable for disconnected networks.

Acupuncture therapies for cancer-related fatigue: A Bayesian network meta-analysis and systematic review

Background

Cancer-related fatigue (CRF) is one of the most commonly reported symptoms impacting cancer survivors. This study evaluated and compared the effectiveness and safety of acupuncture treatments for CRF.

Methods

We searched PubMed, Embase, Web of Science, Cochrane Library, China Biology Medicine China National Knowledge Infrastructure, China Science and Technology Journal Database, and WanFang Database from inception to November 2022 to identify eligible randomized controlled trials (RCTs) comparing acupuncture treatments with sham interventions, waitlist (WL), or usual care (UC) for CRF treatment. The outcomes included the Cancer Fatigue Scale (CFS) and Pittsburgh Sleep Quality Index (PSQI), and pair-wise and Bayesian network meta-analyses were performed using STATA v17.0.

Results

In total, 34 randomized controlled trials featuring 2632 participants were included. In the network meta-analysis, the primary analysis using CFS illustrated that point application (PA) + UC (standardized mean difference [SMD] = −1.33, 95% CI = −2.02, −0.63) had the highest probability of improving CFS, followed by manual acupuncture (MA) + PA (SMD = −1.21, 95% CI = −2.05, −0.38) and MA + UC (SMD = −0.80, 95% CI = −1.50, −0.09). Moreover, the adverse events of these interventions were acceptable.

Conclusion

This study demonstrated that acupuncture was effective and safe on CRF treatment. However, further studies are still warranted by incorporating more large-scale and high-quality RCTs.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO, identifier CRD42022339769.

Taxonomy of Interventions to Reduce Acute Care Transfers From Long-term Care Homes: A Systematic Scoping Review

OBJECTIVE

To develop a taxonomy of interventions aimed at reducing emergency department (ED) transfers and/or hospitalizations from long-term care (LTC) homes.

DESIGN

A systematic scoping review.

SETTING AND PARTICIPANTS

Permanent LTC home residents.

METHODS

Experimental and comparative observational studies were searched in MEDLINE, CINAHL, Embase Classic + Embase, the Cochrane Library, PsycINFO, Social Work Abstracts, AMED, Global Health, Health and Psychosocial Instruments, Joanna Briggs Institute EBP Database, Ovid Healthstar, and Web of Science Core Collection from inception until March 2020. Forward/backward citation tracking and gray literature searches strengthened comprehensiveness. The Mixed Methods Appraisal Tool was used to assess study quality. Intervention categories and components were identified using an inductive-deductive thematic analysis. Categories were informed by 3 intervention dimensions: (1) "when/at what point(s)" on the continuum of care they occur, (2) "for whom" (ie, intervention target resident populations), and (3) "how" these interventions effect change. Components were informed by the logistical elements of the interventions having the potential to influence outcomes. All interventions were mapped to the developed taxonomy based on their categories, components, and outcomes. Distributions of components by category and study year were graphically presented.

RESULTS

Ninety studies (25 randomized, 23 high quality) were included. Six intervention categories were identified: advance care planning; palliative and end-of-life care; onsite care for acute, subacute, or uncontrolled chronic conditions; transitional care; enhanced usual care (most prevalent, 31% of 90 interventions); and comprehensive care. Four components were identified: increasing human resource capacity (most prevalent, 93%), training or reorganization of existing staff, technology, and standardized tools. The use of technology increased over time. Potentially avoidable ED transfers and/or hospitalizations were measured infrequently as primary outcomes.

CONCLUSIONS AND IMPLICATIONS

This proposed taxonomy can guide future intervention designs. It can also facilitate systematic reviews and precise effect size estimations for homogenous interventions when outcomes are comparable.

Impact of pharmacological interventions on intrapulmonary shunt during one-lung ventilation in adult thoracic surgery: a systematic review and component network meta-analysis

BACKGROUND

Intrapulmonary shunt is a major determinant of oxygenation in thoracic surgery under one-lung ventilation. We reviewed the effects of available treatments on shunt, Pao₂/FiO₂ and haemodynamics through systematic review and network meta-analysis.

METHODS

Online databases were searched for RCTs comparing pharmacological interventions and intrapulmonary shunt in thoracic surgery under one-lung ventilation up to March 30, 2022. Random-effects (component) network meta-analysis compared 24 treatments and 19 treatment components. The Confidence in Network Meta-Analysis (CINeMA) framework assessed evidence certainty. The primary outcome was intrapulmonary shunt fraction during one-lung ventilation.

RESULTS

A total of 55 RCTs were eligible for systematic review (2788 participants). The addition of N₂O (mean difference [MD]=-15%; 95% confidence interval [CI], -25 to -5; P=0.003) or almitrine (MD=-13%; 95% CI, -20 to -6; P<0.001) to propofol anaesthesia were efficient at decreasing shunt. Combined epidural anaesthesia (MD=3%; 95% CI, 1-5; P=0.005), sevoflurane (MD=5%; 95% CI, 2-8; P<0.001), isoflurane (MD=6%; 95% CI, 4-9; P<0.001), and desflurane (MD=9%; 95% CI, 4-14; P=0.001) increased shunt vs propofol. Almitrine (MD=147 mm Hg; 95% CI, 58-236; P=0.001), dopexamine (MD=88 mm Hg; 95% CI, 4-171; P=0.039), and iloprost (MD=81 mm Hg; 95% CI, 4-158; P=0.038) improved Pao₂/FiO₂. Certainty of evidence ranged from very low to moderate.

CONCLUSIONS

Adding N₂O or almitrine to propofol anaesthesia reduced intrapulmonary shunt during one-lung ventilation. Halogenated anaesthetics increased shunt in comparison with propofol. The effects of N₂O, iloprost, and dexmedetomidine should be investigated in future research. N₂O results constitute a research hypothesis currently not backed by any direct evidence. The clinical availability of almitrine is limited.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO CRD42022310313.

Interventions for preventing back pain among office workers - a systematic review and network meta-analysis

OBJECTIVE

Back pain is common in the working population. This systematic review with network meta-analysis (NMA) aimed to compare the effects of interventions for preventing back pain among office workers.

METHODS

We searched eight databases and additional sources up to March 2021. We included randomized controlled trials (RCT) and cluster RCT focusing on office workers, comparing work-related interventions aimed at preventing back pain (defined as pain in any part of the spine) to a control condition and assessing back pain and/or work absence. Further outcomes considered were adverse events and participants' satisfaction. We performed both frequentist and component NMA. Risk of bias (RoB) was evaluated using RoB 2 and certainty of the evidence (CoE) was assessed using GRADE.

RESULTS

We screened 9809 records and included 24 studies with a total of 7080 participants. RoB was assessed as "some concerns" or "high" for all studies and outcomes. Included studies investigated multicomponent interventions, ergonomics, physical activity, education, behavioral interventions and no/minimal interventions. Effects were mostly not statistically significant and based on low/very low CoE. Physical activity probably reduces days of work absence slightly [mean difference (MD) -1.10, 95% confidence interval (CI) -2.07- -0.13], and combining physical activity and ergonomics may reduce back pain intensity (standardized MD -0.41, 95% CI -0.80- -0.02) when compared to no/minimal intervention. A large proportion of participants were satisfied with the interventions, adverse events were rarely assessed.

CONCLUSIONS

We observed mostly minor effects of interventions on back pain and work absence among office workers. The practical relevance of these effects is questionable.

Cost-effectiveness of 5 fraction and partial breast radiotherapy for early breast cancer in the UK: model-based multi-trial analysis

PURPOSE

We estimated the cost-effectiveness of 4 radiotherapy modalities to treat early breast cancer in the UK. In a subgroup of patients eligible for all modalities, we compared whole-breast (WB) and partial breast (PB) radiotherapy delivered in either 15 (WB15F, PB15F) or 5 fractions (WB5F, PB5F). In a subgroup ineligible for PB radiotherapy, we compared WB15F to WB5F.

METHODS

We developed a Markov cohort model to simulate lifetime healthcare costs and quality-adjusted life years (QALYs) for each modality. This was informed by the clinical analysis of two non-inferiority trials (FAST Forward and IMPORT LOW) and supplemented with external literature. The primary analysis assumed that radiotherapy modality influences health only through its impact on locoregional recurrence and radiotherapy-related adverse events.

RESULTS

In the primary analysis, PB5F had the least cost and greatest expected QALYs. WB5F had the least cost and the greatest expected QALYs in those only eligible for WB radiotherapy. Applying a cost-effectiveness threshold of £15,000/QALY, there was a 62% chance that PB5F was the cost-effective alternative in the PB eligible group, and there was a 100% chance that WB5F was cost-effective in the subgroup ineligible for PB radiotherapy.

CONCLUSIONS

Hypofractionation to 5 fractions and partial breast radiotherapy modalities offer potentially important benefits to the UK health system.

Graphical tools for visualizing the results of network meta-analysis of multicomponent interventions

Network meta-analysis (NMA) is an established method for assessing the comparative efficacy and safety of competing interventions. It is often the case that we deal with interventions that consist of multiple, possibly interacting, components. Examples of interventions' components include characteristics of the intervention, mode (face-to-face, remotely etc.), location (hospital, home etc.), provider (physician, nurse etc.), time of communication (synchronous, asynchronous etc.) and other context related components. Networks of multicomponent interventions are typically sparse and classical NMA inference is not straightforward and prone to confounding. Ideally, we would like to disentangle the effect of each component to find out what works (or does not work). To this aim, we propose novel ways of visualizing the NMA results, describe their use, and illustrate their application in real-life examples. We developed an R package viscomp to produce all the suggested figures.

Combination of antiplatelet and anticoagulant therapy, component network meta-analysis of randomized controlled trials

Background

Despite numerous randomized clinical trials (RCT), data regarding the efficacy of antiplatelet and anticoagulant combinations are still conflicting. We aimed to analyze treatment options tested in various fields of cardiovascular prevention, regarding their efficacy and bleeding risk.

Methods

Systematic searches of electronic databases were conducted until June 2022. A component network meta-analysis was performed in R. Risk estimates across trials were pooled using random-effects model selecting risk ratio (RR) with 95% confidence intervals (95% CIs) as summary statistics. The primary endpoint of interest was the rate of major cardiac adverse events (MACE). Major bleeding events were assessed as main safety endpoint. Secondary outcomes included cardiovascular- and overall mortality, myocardial infarction (MI), stent thrombosis, and stroke.

Results

Fifteen studies randomizing 73,536 patients were identified. The MACE risk reflected heterogeneity among the anticoagulants with dabigatran and apixaban significantly reducing the risk of MACE (RR 0.56; 95% CI 0.39-0.80 and RR 0.75; 95% CI 0.58-0.98, respectively). Vitamin K antagonist (VKA), rivaroxaban, or edoxaban did not reduced of MACE while it was associated with a significant increase of bleeding risk (RR 1.66; 3.66, and 5.47, respectively). The direct anticoagulant (DOAC) dose reduction resulted in tendencies of fewer bleeding but higher MACE risk, while combination with aspirin was followed with increased risk for bleeding, however, remained non-significant in these cases.

Conclusion

Our meta-analysis supports that the ischemic-bleeding balance is different among direct-acting oral anticoagulants (DOACs) while this is not significantly affected by the dose reduction approaches. Long-term aspirin treatment as part of the anticoagulant and dual antiplatelet regimen provides no ischemic benefit but may increase bleeding risk.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/], identifier [259703].

Management of Chronic Subdural Hematoma: A Systematic Review and Component Network Meta-analysis of 455 Studies With 103 645 Cases

BACKGROUND

Chronic subdural hematoma (CSDH) is a common neurosurgical condition with a high risk of recurrence after treatment.

OBJECTIVE

To assess and compare the risk of recurrence, morbidity, and mortality across various treatments for CSDH.

METHODS

A systematic review and meta-analysis was performed. PubMed/MEDLINE, EMBASE, SCOPUS, and Web of Science were searched from January 01, 2000, to July 07, 2021. The primary outcome was recurrence, and secondary outcomes were morbidity and mortality. Component network meta-analyses (CNMAs) were performed for surgical and medical treatments, assessing recurrence and morbidity. Incremental risk ratios (iRRs) with 95% CIs were estimated for each component.

RESULTS

In total, 12 526 citations were identified, and 455 studies with 103 645 cases were included. Recurrence occurred in 11 491/93 525 (10.8%, 95% CI 10.2-11.5, 418 studies) cases after surgery. The use of a postoperative drain (iRR 0.53, 95% CI 0.44-0.63) and middle meningeal artery embolization (iRR 0.19, 95% CI 0.05-0.83) reduced recurrence in the surgical CNMA. In the pharmacological CNMA, corticosteroids (iRR 0.47, 95% CI 0.36-0.61) and surgical intervention (iRR 0.11, 95% CI 0.07-0.15) were associated with lower risk. Corticosteroids were associated with increased morbidity (iRR 1.34, 95% CI 1.05-1.70). The risk of morbidity was equivalent across surgical treatments.

CONCLUSION

Recurrence after evacuation occurs in approximately 10% of cSDHs, and the various surgical interventions are approximately equivalent. Corticosteroids are associated with reduced recurrence but also increased morbidity. Drains reduce the risk of recurrence, but the position of drain (subdural vs subgaleal) did not influence recurrence. Middle meningeal artery embolization is a promising treatment warranting further evaluation in randomized trials.

Identifying relative efficacy of components of prehabilitation in adult surgical patients: protocol for a systematic review and component network meta-analysis

INTRODUCTION

Prehabilitation is a high-priority intervention for patients, the public, clinicians and health systems. However, existing knowledge syntheses are generally low quality and do not provide insights regarding the relative efficacy of different prehabilitation components (eg, exercise, nutrition, psychosocial or cognitive interventions). The objective of the planned review is to evaluate the relative efficacy of different prehabilitation components to inform current care, implementation and future research.

METHODS AND ANALYSIS

We will perform a systematic review and component network meta-analysis (CNMA). We will use a peer-reviewed search strategy to identify all randomised trials of prehabilitation in adult surgical patients from Ovid Medline, Embase, the CINAHL, PsycINFO, Web of Science and the Cochrane Central Register of Controlled Trials, along with grey literature. All stages of the review and data extraction process will be performed in duplicate, following recommended best practices. To compare the relative efficacy of different prehabilitation components (prespecified as exercise, nutrition, psychosocial or cognitive interventions), we will use CNMA, an extension of network meta-analysis that allows estimation of the contributions to efficacy of each component of a multicomponent intervention through direct and indirect comparisons. We will use additive CNMA models for critical outcomes (postoperative complications, patient-reported recovery, physical recovery and length of stay); standard care will be the common reference condition. Pre-specified sensitivity and subgroup analyses will be conducted.

ETHICS AND DISSEMINATION

This review of published data does not require ethical review. Results will be disseminated via scientific conferences, peer-reviewed publications, social and traditional media and via our research network to target partners and organisations.

Network Meta-analysis on Disconnected Evidence Networks When Only Aggregate Data Are Available: Modified Methods to Include Disconnected Trials and Single-Arm Studies while Minimizing Bias

BACKGROUND

Network meta-analysis (NMA) requires a connected network of randomized controlled trials (RCTs) and cannot include single-arm studies. Regulators or academics often have only aggregate data. Two aggregate data methods for analyzing disconnected networks are random effects on baseline and aggregate-level matching (ALM). ALM has been used only for single-arm studies, and both methods may bias effect estimates.

METHODS

We modified random effects on baseline to separate RCTs connected to and disconnected from the reference and any single-arm studies, minimizing the introduction of bias. We term our modified method reference prediction. We similarly modified ALM and extended it to include RCTs disconnected from the reference. We tested these methods using constructed data and a simulation study.

RESULTS

In simulations, bias for connected treatments for ALM ranged from -0.0158 to 0.051 and for reference prediction from -0.0107 to 0.083. These were low compared with the true mean effect of 0.5. Coverage ranged from 0.92 to 1.00. In disconnected treatments, bias of ALM ranged from -0.16 to 0.392 and of reference prediction from -0.102 to 0.40, whereas coverage of ALM ranged from 0.30 to 0.82 and of reference prediction from 0.64 to 0.94. Under fixed study effects for disconnected evidence, bias was similar, but coverage was 0.81 to 1.00 for reference prediction and 0.18 to 0.76 for ALM. Trends of similar bias but greater coverage for reference prediction with random study effects were repeated in constructed data.

CONCLUSIONS

Both methods with random study effects seem to minimize bias in treatment connected to the reference. They can estimate treatment effects for disconnected treatments but may be biased. Reference prediction has greater coverage and may be recommended overall.

HIGHLIGHTS

Two methods were modified for network meta-analysis on disconnected networks and for including single-arm observational or interventional studies in network meta-analysis using only aggregate data and for minimizing the bias of effect estimates for treatments only in trials connected to the reference.Reference prediction was developed as a modification of random effects on baseline that keeps analyses of trials connected to the reference separately from those disconnected from the reference and from single-arm studies. The method was further modified to account for correlation in trials with more than 2 arms and, under random study effects, to estimate variance in heterogeneity separately in connected and disconnected evidence.Aggregate-level matching was extended to include trials disconnected from the reference, rather than only single-arm studies. The method was further modified to separately estimate treatment effects and heterogeneity variance in the connected and disconnected evidence and to account for the correlation between arms in trials with more than 2 arms.Performance was assessed using a constructed data example and simulation study.The methods were found to have similar, and sometimes low, bias when estimating the relative effects for disconnected treatments, but reference prediction with random study effects had the greatest coverage.The use of reference prediction with random study effects for disconnected networks is recommended if no individual patient data or alternative real-world evidence is available.

Bayesian unanchored additive models for component network meta-analysis

Component network meta-analysis (CNMA) models are an extension of standard network meta-analysis (NMA) models which account for the use of multicomponent treatments in the network. This article contributes innovatively to several statistical aspects of CNMA. First, by introducing a unified notation, we establish that currently available methods differ in the way they assume additivity, an important distinction that has been overlooked so far in the literature. In particular, one model uses a more restrictive form of additivity than the other which we term an anchored and unanchored model, respectively. We show that an anchored model can provide a poor fit to the data if it is misspecified. Second, given that Bayesian models are often preferred by practitioners, we develop two novel unanchored Bayesian CNMA models presented under the unified notation. An extensive simulation study examining bias, coverage probabilities, and treatment rankings confirms the favorable performance of the novel models. This is the first simulation study to compare the statistical properties of CNMA models in the literature. Finally, the use of our novel models is demonstrated on a real dataset, and the results of CNMA models on the dataset are compared.

Psychological interventions for inflammatory bowel disease: a systematic review and component network meta-analysis protocol

INTRODUCTION

Patients with inflammatory bowel diseases (IBD) often report psychological problems, unemployment, disability, sick leave and compromised quality of life. The effect of psychological interventions on health-related outcomes in IBD is controversial as previous reviews faced the obstacle of high heterogeneity among provided multimodular interventions. The heterogeneity can be addressed with network meta-analysis (NMA) and (multi)component NMA (CNMA). We aim to investigate whether psychological interventions can improve quality of life, clinical and social outcomes in IBD using NMA and CNMA. This is the study protocol.

METHODS AND ANALYSIS

We will consider randomised, quasi-randomised and non-randomised controlled trials, including cluster randomised and cross-over trials with 2 months of minimum follow-up. The conditions to be studied comprise Crohn's disease and ulcerative colitis in children, adolescents and adults. We will include any psychological intervention aiming to change the health status of the study participant.We will search Medline, Embase, Web of Science, CENTRAL, LILACS, Psyndex, PsycINFO, Google Scholar and trial registries from inception (the search will be updated before the review completion). Two authors will independently screen all references based on titles and abstracts. For data extraction, standard forms are developed and tested before extraction. All information will be assessed independently by at least two reviewers, and disagreements solved by consensus discussion or a third rater if necessary.The data synthesis will include a pairwise meta-analysis supported by meta-regression. We will conduct NMA (all treatments will constitute single nodes of the network) and CNMA (we will define all treatments as sums of core components, eg, cognitive +behaviour, or cognitive +behaviour + relaxation, and additionally consider interactions) using the R Package netmeta.

ETHICS AND DISSEMINATION

No ethical approval is required. Reports will include the final report to the funder, conference presentation, peer-reviewed publication and a patient report.

PROSPERO REGISTRATION NUMBER

CRD42021250446.

Comparing efficacy and safety in catheter ablation strategies for atrial fibrillation: a network meta-analysis

BACKGROUND

There is no consensus on the most efficient catheter ablation (CA) strategy for patients with atrial fibrillation (AF). The objective of this study was to compare the efficacy and safety of different CA strategies for AF ablation through network meta-analysis (NMA).

METHODS

A systematic search of PubMed, Web of Science, and CENTRAL was performed up to October 5th, 2020. Randomized controlled trials (RCT) comparing different CA approaches were included. Efficacy was defined as arrhythmia recurrence after CA and safety as any reported complication related to the procedure during a minimum follow-up time of 6 months.

RESULTS

In total, 67 RCTs (n = 9871) comparing 19 different CA strategies were included. The risk of recurrence was significantly decreased compared to pulmonary vein isolation (PVI) alone for PVI with renal denervation (RR: 0.60, CI: 0.38-0.94), PVI with ganglia-plexi ablation (RR: 0.62, CI: 0.41-0.94), PVI with additional ablation lines (RR: 0.8, CI: 0.68-0.95) and PVI in combination with bi-atrial modification (RR: 0.32, CI: 0.11-0.88). Strategies including PVI appeared superior to non-PVI strategies such as electrogram-based approaches. No significant differences in safety were observed.

CONCLUSIONS

This NMA showed that PVI in combination with additional CA strategies, such as autonomic modulation and additional lines, seem to increase the efficacy of PVI alone. These strategies can be considered in treating patients with AF, since, additionally, no differences in safety were observed. This study provides decision-makers with comprehensive and comparative evidence about the efficacy and safety of different CA strategies.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registry number: CRD42020169494 .

Network meta-analysis and random walks

Network meta-analysis (NMA) is a central tool for evidence synthesis in clinical research. The results of an NMA depend critically on the quality of evidence being pooled. In assessing the validity of an NMA, it is therefore important to know the proportion contributions of each direct treatment comparison to each network treatment effect. The construction of proportion contributions is based on the observation that each row of the hat matrix represents a so-called "evidence flow network" for each treatment comparison. However, the existing algorithm used to calculate these values is associated with ambiguity according to the selection of paths. In this article, we present a novel analogy between NMA and random walks. We use this analogy to derive closed-form expressions for the proportion contributions. A random walk on a graph is a stochastic process that describes a succession of random "hops" between vertices which are connected by an edge. The weight of an edge relates to the probability that the walker moves along that edge. We use the graph representation of NMA to construct the transition matrix for a random walk on the network of evidence. We show that the net number of times a walker crosses each edge of the network is related to the evidence flow network. By then defining a random walk on the directed evidence flow network, we derive analytically the matrix of proportion contributions. The random-walk approach has none of the associated ambiguity of the existing algorithm.

Acupuncture in addition to usual care for patients with irritable bowel syndrome: a component network meta-analysis

OBJECTIVE

The efficacy of acupuncture alone in the treatment of irritable bowel syndrome (IBS) is controversial, but the benefit of acupuncture added to usual care has rarely been studied. We aimed to examine the benefit of acupuncture added to usual care through network meta-analysis (NMA).

METHODS

PubMed, Embase, and the Cochrane Register of Controlled Trials (CENTRAL) were searched from their inception to 1 July 2021, without any language restriction. Randomized controlled trials (RCTs) testing the effect of acupuncture alone or acupuncture combined with usual care for IBS were included. The primary outcome was improvement of global IBS symptoms. Standard NMA was performed to compare differential combinations of acupuncture (including manual acupuncture (MA) and electroacupuncture (EA)), and component network meta-analysis (CNMA) was subsequently performed to determine whether acupuncture provided additional benefits to usual care. The effect size of an intervention was measured using relative ratio (RR).

RESULTS

We included 25 RCTs (n = 3041 participants) after screening 582 retrieved articles. Five RCTs were classified as low risk of bias. The results of standard NMA showed that MA combined with usual care ranked the most effective (sham acupuncture as common comparator; RR = 1.96 (95% confidence interval (CI) 1.23 to 3.12)). The results of CNMA showed that MA was the most effective component (RR = 1.38 (95% CI, 1.12 to 1.70)) when added to usual care.

CONCLUSION

Acupuncture provided additional benefits to usual care, and it might be considered as adjunctive therapy for patients who respond inadequately to usual care.

Low FODMAP Diet and Probiotics in Irritable Bowel Syndrome: A Systematic Review With Network Meta-analysis

Background: Probiotic and low fermentable oligosaccharide, disaccharide, monosaccharide, and polyol (FODMAP) diet are two commonly used management approaches for patients with irritable bowel syndrome (IBS). We aimed to evaluate the most effective combinations and components among different probiotics or low FODMAP diet through component network meta-analysis (NMA).

Methods: We searched Embase, Ovid Medline, and Web of Science from inception to 21 January 2021. Randomized controlled trials (RCTs) examining the efficacy of probiotics and low FODMAP diet for IBS were included, with placebo, sham diet, or conventional treatments as controls. Binary outcomes were compared among treatments using the relative ratio (RR). A minimally contextualized framework recommended by the GRADE group was used to evaluate the certainty of evidence. The primary efficacy outcome was the relief of global IBS symptoms, and the secondary efficacy outcome was the reduction in IBS symptom scores or abdominal pain scores.

Key Results: We included 76 RCTs (n = 8058) after screening 1940 articles. Eight RCTs were classified as low risk of bias. Standard network meta-analysis (NMA) showed that Lactobacillus (RR 1.74, 95% CI 1.22–2.48) and Bifidobacterium (RR 1.76, 95% CI 1.01–3.07) were the most effective for the primary efficacy outcome (high certainty evidence); component NMA showed that Bacillus (RR 5.67, 95% CI 1.88 to 17.08, p = 0.002) and Lactobacillus (RR 1.42, 95% CI 1.07 to 1.91, p = 0.017) were among the most effective components. The results of standard NMA and CNMA analysis of the improvement of overall IBS symptom scores or abdominal pain scores were consistent with this finding.

Conclusion:Lactobacillus was the most effective component for the relief of IBS symptoms; Bifidobacterium and Bacillus were possibly effective and need further verification.

Systematic Review Registration: website, identifier registration number.

Bayesian models for aggregate and individual patient data component network meta-analysis

Network meta-analysis can synthesize evidence from studies comparing multiple treatments for the same disease. Sometimes the treatments of a network are complex interventions, comprising several independent components in different combinations. A component network meta-analysis (CNMA) can be used to analyze such data and can in principle disentangle the individual effect of each component. However, components may interact with each other, either synergistically or antagonistically. Deciding which interactions, if any, to include in a CNMA model may be difficult, especially for large networks with many components. In this article, we present two Bayesian CNMA models that can be used to identify prominent interactions between components. Our models utilize Bayesian variable selection methods, namely the stochastic search variable selection and the Bayesian LASSO, and can benefit from the inclusion of prior information about important interactions. Moreover, we extend these models to combine data from studies providing aggregate information and studies providing individual patient data (IPD). We illustrate our models in practice using three real datasets, from studies in panic disorder, depression, and multiple myeloma. Finally, we describe methods for developing web-applications that can utilize results from an IPD-CNMA, to allow for personalized estimates of relative treatment effects given a patient's characteristics.

Mortality in cardiogenic shock patients receiving mechanical circulatory support: a network meta-analysis

Objective

Mechanical circulatory support (MCS) devices are widely used for cardiogenic shock (CS). This network meta-analysis aims to evaluate which MCS strategy offers advantages.

Methods

A systemic search of PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials was performed. Studies included double-blind, randomized controlled, and observational trials, with 30-day follow-ups. Paired independent researchers conducted the screening, data extraction, quality assessment, and consistency and heterogeneity assessment.

Results

We included 39 studies (1 report). No significant difference in 30-day mortality was noted between venoarterial extracorporeal membrane oxygenation (VA-ECMO) and VA-ECMO plus Impella, Impella, and medical therapy. According to the surface under the cumulative ranking curve, the optimal ranking of the interventions was surgical venting plus VA-ECMO, medical therapy, VA-ECMO plus Impella, intra-aortic balloon pump (IABP), Impella, Tandem Heart, VA-ECMO, and Impella plus IABP. Regarding in-hospital mortality and 30-day mortality, the forest plot showed low heterogeneity. The results of the node-splitting approach showed that direct and indirect comparisons had a relatively high consistency.

Conclusions

IABP more effectively reduce the incidence of 30-day mortality compared with VA-ECMO and Impella for the treatment of CS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02493-0.

A Systematic Review and Network Meta-Analysis of Pharmacological Treatment of Heart Failure With Reduced Ejection Fraction

OBJECTIVES

This study sought to estimate and compare the aggregate treatment benefit of pharmacological therapy for heart failure (HF) with reduced ejection fraction.

BACKGROUND

The estimated treatment effects of various combinations of contemporary HF medical therapies are not well characterized.

METHODS

We performed a systematic network meta-analysis, using MEDLINE/EMBASE and the Cochrane Central Register of Controlled Trials for randomized controlled trials published between January 1987 and January 2020. We included angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta-blockers (BB), mineralocorticoid receptor antagonists (MRAs), digoxin, hydralazine-isosorbide dinitrate, ivabradine, angiotensin receptor-neprilysin inhibitors (ARNi), sodium glucose cotransporter-2 inhibitors (SGLT2i), vericiguat, and omecamtiv-mecarbil. The primary outcome was all-cause death. We estimated the life-years gained in 2 HF populations (BIOSTAT-CHF [BIOlogy Study to TAilored Treatment in Chronic Heart Failure] and ASIAN-HF [Asian Sudden Cardiac Death in Heart Failure Registry]).

RESULTS

We identified 75 relevant trials representing 95,444 participants. A combination of ARNi, BB, MRA, and SGLT2i was most effective in reducing all-cause death (HR: 0.39; 95% CI: 0.31-0.49); followed by ARNi, BB, MRA, and vericiguat (HR: 0.41; 95% CI: 0.32-0.53); and ARNi, BB, and MRA (HR: 0.44; 95% CI: 0.36-0.54). Results were similar for the composite outcome of cardiovascular death or first hospitalization for HF (HR: 0.36; 95% CI: 0.29-0.46 for ARNi, BB, MRA, and SGLT2i; HR: 0.44; 95% CI: 0.35-0.56 for ARNi, BB, MRA, and omecamtiv-mecarbil; and HR: 0.43; 95% CI: 0.34-0.55 for ARNi, BB, MRA, and vericiguat). The estimated additional number of life-years gained for a 70-year-old patient on ARNi, BB, MRA, and SGLT2i was 5.0 years (2.5-7.5 years) compared with no treatment in secondary analyses.

CONCLUSIONS

In patients with HF with reduced ejection fraction, the estimated aggregate benefit is greatest for a combination of ARNi, BB, MRA, and SGLT2i.

Software to Conduct a Meta-Analysis and Network Meta-Analysis

Statistical software for meta-analysis (MA) and network meta-analysis (NMA) have become indispensable for researchers. The aim of this chapter is to introduce key features of MA and NMA software to compare the effectiveness of interventions. Commonly used or routinely maintained statistical software are reviewed, including commercial and open-sourced programs such as Stata, R and Excel plug-ins. It does not provide a comprehensive overview of all features available in the software covered. Rather, it focuses on the essential features required to carry out an MA or NMA . This chapter begins with a review of key considerations when implementing an MA or NMA , then presents a summary of the software. Key features of each software option are discussed.

Comparative efficacy and safety of glucose-lowering drugs in children and adolescents with type 2 diabetes: A systematic review and network meta-analysis

OBJECTIVE

Type 2 diabetes is more common in adults, but is becoming the major concern in children and adolescent recently. This study aimed to provide additional pharmaceutical management for children and adolescents with type 2 diabetes by assessing the efficacy and safety of several glucose-lowering drugs.

METHODS

Searches were performed in PubMed, Medline, Ovid, Cochrane Controlled Register of Trials (CENTRAL), and ClinicalTrials.gov that reported the efficacy and safety of drugs for children and adolescents with type 2 diabetes. Pooled effects were calculated by frequentist fixed effects network meta-analyses and additive network meta-analyses.

RESULTS

A total of 12 trials assessing eight glucose-lowering drugs were included, which compose of seven trials with monotherapy and five trials with combination therapies. Network meta-analysis results showed compared to placebo, saxagliptin+metformin (mean difference (MD) -1.91% [-2.85%, -0.97%]), liraglutide+metformin (MD -1.45% [-1.65%, -1.26%]), and liraglutide (MD -0.90% [-1.35%, -0.45%]) were the top 3 drugs that significantly reduced hemoglobin A1c (HbA1c). Sitagliptin+metformin, dapagliflozin, exenatide-2mcg, linagliptin-5mg, metformin, exenatide-5/10mcg, glimepiride, and sitagliptin also showed significant reduction in HbA1c. There were no significant differences between treatments in the incidence of adverse events, except that liraglutide+metformin had significant adverse effect such as abdominal pain. In addition, dapagliflozin, sitagliptin+metformin, and saxagliptin+metformin showed better efficacy compared with FDA-approved drugs.

CONCLUSIONS

The top 10 treatments of type 2 diabetes in children and adolescents aged 10-17 years were saxagliptin+metformin, liraglutide+metformin, liraglutide, dapagliflozin, exenatide-2 mcg, sitagliptin+metformin, linagliptin-5 mg, linagliptin-1 mg, metformin, and exenatide-5/10 mcg.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=284897, identifier CRD42021284897.

Network meta-analysis for comparative effectiveness of treatments for chronic low back pain disorders: systematic review protocol

INTRODUCTION

Chronic low back pain disorders (CLBDs) present a substantial societal burden; however, optimal treatment remains debated. To date, pairwise and network meta-analyses have evaluated individual treatment modes, yet a comparison of a wide range of common treatments is required to evaluate their relative effectiveness. Using network meta-analysis, we aim to evaluate the effectiveness of treatments (acupuncture, education or advice, electrophysical agents, exercise, manual therapies/manipulation, massage, the McKenzie method, pharmacotherapy, psychological therapies, surgery, epidural injections, percutaneous treatments, traction, physical therapy, multidisciplinary pain management, placebo, 'usual care' and/or no treatment) on pain intensity, disability and/or mental health in patients with CLBDs.

METHODS AND ANALYSIS

Six electronic databases and reference lists of 285 prior systematic reviews were searched. Eligible studies will be randomised controlled/clinical trials (including cross-over and cluster designs) that examine individual treatments or treatment combinations in adult patients with CLBDs. Studies must be published in English, German or Chinese as a full-journal publication in a peer-reviewed journal. A narrative approach will be used to synthesise and report qualitative and quantitative data, and, where feasible, network meta-analyses will be performed. Reporting of the review will be informed by Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidance, including the network meta-analysis extension (PRISMA-NMA). The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach for network meta-analysis will be implemented for assessing the quality of the findings.

ETHICS AND DISSEMINATION

Ethical approval is not required for this systematic review of the published data. Findings will be disseminated via peer-reviewed publication.

PROSPERO REGISTRATION NUMBER

PROSPERO registration number CRD42020182039.

Interventions to reduce the incidence of surgical site infection in colorectal resections: systematic review with multicomponent network meta-analysis (INTRISSI): study protocol

OBJECTIVE

To assess the relative contribution of intravenous antibiotic prophylaxis, mechanical bowel preparation, oral antibiotic prophylaxis, and combinations thereof towards the reduction of surgical site infection (SSI) incidence in elective colorectal resections.

METHODS AND ANALYSIS

A systematic search of randomised controlled trials comparing interventions to reduce SSI incidence will be conducted with predefined search terms in the following databases: MEDLINE, LILACS, Cochrane Central Register of Controlled Trials (CENTRAL) and the Cochrane Database of Systematic Reviews (CDSR). Additionally, several online databases will be searched for ongoing trials, and conference proceedings and reference lists of retrieved articles will be hand searched. The title-abstract screening will be partly performed by means of a semiautomated supervised machine learning approach, which will be trained on a subset of the identified titles and abstracts identified through traditional screening methods.The primary analysis will be a multicomponent network meta-analysis, as we expect to identify studies that investigate combinations of interventions (eg, mechanical bowel preparation combined with oral antibiotics) as well as studies that focus on individual components (mechanical bowel preparation or oral antibiotics). By means of a multicomponent network meta-analysis, we aim at estimating the effects of the separate components along the effects of the observed combinations. To account for between-trial heterogeneity, a random-effect approach will be combined with inverse variance weighting for estimation of the treatment effects. Associated 95% CIs will be calculated as well as the ranking for each component in the network using P scores. Results will be visualised by network graphics and forest plots of the overall pairwise effect estimates. Comparison-adjusted funnel plots will be used to assess publication bias.

ETHICS AND DISSEMINATION

Ethical approval by the Ethical Committee of the Medical Faculty of the Martin-Luther-University Halle-Wittenberg (ID of approval: 2021-148). Results shall be disseminated directly to decision-makers (eg, surgeons, gastroenterologists, wound care specialists) by means of publication in peer-reviewed journals, presentation at conferences and through the media (eg, radio, TV, etc).

PROSPERO REGISTRATION NUMBER

CRD42021267322.

Relative effectiveness of non-surgical interventions for pain management in knee osteoarthritis: a protocol for a component network meta-analysis of randomised controlled trials

INTRODUCTION

Knee osteoarthritis is a chronic degenerative disease associated with significant chronic pain, disability and impaired quality of life and is the most common form of osteoarthritis. There is no cure for knee osteoarthritis, and the main therapeutic goals are pain management and improving quality of life. The objective of this study is to evaluate the relative efficacy and acceptability of available interventions using network meta-analysis (NMA) to provide a comprehensive evidence base to inform future treatment guidelines.

METHODS AND ANALYSIS

A comprehensive literature search of major electronic databases (MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials) and clinical trial registries will identify randomised control trials (RCTs) of interventions listed in NICE guidelines for the treatment of knee osteoarthritis in adults. We will perform an NMA to estimate relative intervention effects across the whole treatment network. If any studies use multicomponent intervention packages, we will employ a component NMA model to estimate the contribution of individual components. The quality of evidence will be assessed using the Confidence in Network Meta-Analysis approach, which is based on the traditional GRADE framework adapted for NMA. Risk of bias (RoB) will be assessed using the revised Cochrane RoB 2.0 tool for RCTs.

ETHICS AND DISSEMINATION

This study does not require ethical approval. Findings will be submitted to a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42020184192.

Glucose-lowering Drugs and Hospitalization for Heart Failure: A Systematic Review and Additive-effects Network Meta-analysis With More Than 500 000 Patient-years

BACKGROUND

Sodium glucose co-transporter 2 inhibitors (SGLT2is) prevent hospitalization resulting from heart failure (HHF). However, patients with type 2 diabetes mellitus use multiple antihyperglycemic drugs to achieve glycosylated hemoglobin (HbA1c) targets. In these drug combinations, the risk of HHF is unpredictable and so is the parallel effect of glucose-lowering.

PURPOSE

To examine the impact of antihyperglycemic drugs and their association on HHF.

DATA SOURCES

Forty randomized controlled trials (RCTs) reporting HHF.

STUDY SELECTION

Published RCTs were the data source.

DATA EXTRACTION

Incidence rates of HHF.

DATA SYNTHESIS

Random additive-effects network meta-analysis showed that metformin (P = 0.55), sulfonylureas (P = 0.51), glucagon-like peptide-1 receptor-agonist (P = 0.16), and dipeptidyl peptidase 4 inhibitors (DPP4is; P = 0.54) were neutral on the risk of HHF. SGLT2is and SGLT2is + DPP4is reduced the risk of HHF with a hazard ratio (HR) of 0.68 (95% CI, 0.60-0.76; P < 0.0001) and 0.70 (95% CI, 0.60-0.81; P < 0.0001), respectively. Increased risk of HHF was associated with thiazolidinediones (TZDs) as monotherapy or in combination with DPP4is (HR: 1.45; 95% CI, 1.18-1.78; P = 0.0004) and 1.49 (95% CI, 1.18-1.88; P = 0.0008), respectively. Regardless of the therapy, a 1% reduction in HbA1c reduced the risk of HHF by 31.3% (95% CI, 9-48; P = 0.009).

LIMITATIONS

There are no data to verify drug combinations available for clinical use and to discriminate the effect of drugs within each of the therapeutic classes.

CONCLUSIONS

The risk of HHF is reduced by SGLT2is as monotherapy or in combination with DPP4is and increased by TZDs as monotherapy or in combination. Glucose-lowering provides an additive effect of reducing HHF.

Modeling Multicomponent Interventions in Network Meta-Analysis

There is a rapid increase in trials assessing healthcare interventions consisting of a combination of drugs (polytherapies) or multiple components. In the latter type of interventions (also known as complex interventions), the aspect of complexity is of paramount importance. For example, nonpharmacological interventions, such as psychological interventions or self-management interventions, usually share common components that relate to the nature of intervention, who delivers it, or where and how. In a network of trials, there is often the need to identify the most effective (or safest) component and/or combination of components. Four key meta-analytical approaches have been presented in the literature to handle complex interventions. These include (a) the single-effect model, (b) the full interaction model, (c) the additive main effects model, and (d) the two-way interaction model. In this chapter, we present and discuss the advantages and limitations of these approaches. We illustrate these methods using a network that assesses the relative effects of self-management interventions on waist size in patients with type 2 diabetes.

Concepts and emerging issues of network meta-analysis

Most diseases have more than two interventions or treatment methods, and the application of network meta-analysis (NMA) studies to compare and evaluate the superiority of each intervention or treatment method is increasing. Understanding the concepts and processes of systematic reviews and meta-analyses is essential to understanding NMA. As with systematic reviews and meta-analyses, NMA involves specifying the topic, searching for and selecting all related studies, and extracting data from the selected studies. To evaluate the effects of each treatment, NMA compares and analyzes three or more interventions or treatment methods using both direct and indirect evidence. There is a possibility of several biases when performing NMA. Therefore, key assumptions like similarity, transitivity, and consistency should be satisfied when performing NMA. Among these key assumptions, consistency can be evaluated and quantified by statistical tests. This review aims to introduce the concepts of NMA, analysis methods, and interpretation and presentation of the results of NMA. It also briefly introduces the emerging issues in NMA, including methods for evaluation of consistency.

Progress and challenges of network meta-analysis

In the past years, network meta-analysis (NMA) has been widely used among clinicians, guideline makers, and health technology assessment agencies and has played an important role in clinical decision-making and guideline development. To inform further development of NMAs, we conducted a bibliometric analysis to assess the current status of published NMA methodological studies, summarized the methodological progress of seven types of NMAs, and discussed the current challenges of NMAs.

Dismantling internet-based cognitive behavioral therapy for tinnitus. The contribution of applied relaxation: A randomized controlled trial

BACKGROUND

Internet-based cognitive behavioral therapy (ICBT) for tinnitus is an evidence-based intervention. The components of ICBT for tinnitus have, however, not been dismantled and thus the effectiveness of the different therapeutic components is unknown. It is, furthermore, not known if heterogeneous tinnitus subgroups respond differently to ICBT.

AIMS

This dismantling study aimed to explore the contribution of applied relaxation within ICBT for reducing tinnitus distress and comorbidities associated with tinnitus. A secondary aim was to assess whether outcomes varied for three tinnitus subgroups, namely those with significant tinnitus severity, those with low tinnitus severity, and those with significant depression.

METHODS

A parallel randomized controlled trial design (n = 126) was used to compare audiologist-guided applied relaxation with the full ICBT intervention. Recruitment was online and via the intervention platform. Assessments were completed at four-time points including a 2-month follow-up period. The primary outcome was tinnitus severity as measured by the Tinnitus Functional Index. Secondary outcomes were included for anxiety, depression, insomnia, negative tinnitus cognitions, health-related quality of life, hearing disability, and hyperacusis. Treatment engagement variables including the number of logins, number of modules opened, and the number of messages sent. Both an intention-to-treat analysis and completer's only analysis were undertaken.

RESULTS

Engagement was low which compromised results as the full intervention was undertaken by few participants. Both the ICBT and applied relaxation resulted in large reduction of tinnitus severity (within-group effect sizes d = 0.87 and 0.68, respectively for completers only analysis), which were maintained, or further improved at follow-up. These reductions in tinnitus distress were greater for the ICBT group, with a small effect size differences (between-group d = 0.15 in favor of ICBT for completers only analysis). Tinnitus distress decreased the most at post-intervention for those with significant depression at baseline. Both ICBT and applied relaxation contributed to significant reductions on most secondary outcome measures, with no group differences, except for a greater reduction of hyperacusis in the ICBT group.

CONCLUSION

Due to poor compliance partly attributed to the COVID-19 pandemic results were compromised. Further studies employing strategies to improve compliance and engagement are required. The intervention's effectiveness increased with initial level of tinnitus distress; those with the highest scores at intake experienced the most substantial changes on the outcome measures. This may suggest tailoring of interventions according to tinnitus severity. Larger samples are needed to confirm this.

Work-related interventions for preventing back pain-protocol for a systematic review and network meta-analysis

BACKGROUND

Back pain is a widespread health problem that accounts for substantial disability and high costs. The workplace is considered to critically affect the occurrence and persistence of back pain and therefore offers an important opportunity for preventive interventions. Various work-related intervention strategies including both single- and multicomponent interventions have been developed and evaluated so far. To determine their effectiveness, a method of analysis is needed that particularly meets the challenges of the multidimensionality and diversity of these interventions. This planned systematic review and network meta-analysis aims to compare the effects of different work-related interventions for preventing non-specific back pain in people within a formal employment-related context.

METHODS

We will search the following databases: CENTRAL, MEDLINE, Web of Science, CINAHL, PsycINFO, PEDro, SPORTDiscus, and Academic Search Premier from their inception onwards, as well as additional sources. Randomized controlled trials (RCTs) and cluster-RCTs will be considered if they (1) include people within a formal employment-related context, (2) include people without back pain or mixed samples (i.e., people with and without back pain), (3) compare one or more work-related preventive intervention(s) to a control condition, and (4) assess non-specific back pain (incidence or/and pain intensity), ability to work (numbers of participants or/and numbers of days absent from work), intervention-related adverse events or/and self-reported satisfaction with the intervention. Random-effects pairwise meta-analyses and frequentist network meta-analyses will be conducted where appropriate. We will calculate summary effect sizes for each comparison of interventions and rank interventions according to their P scores. If feasible, we will conduct additional component network meta-analyses. We plan to conduct subgroup analyses for job exposure, intervention duration, baseline back pain, different localizations of back pain, and gender. Risk of bias will be assessed using RoB 2 and the certainty of the evidence will be rated using the GRADE approach.

DISCUSSION

This systematic review aims to identify work-related intervention strategies as well as components within work-related interventions that are effective for preventing back pain. We expect the results to provide guidance for selecting the most promising interventions and foster the purposeful use of resources. Additionally, they may inform the development and implementation of work-related interventions as well as the design of future research in this field.

TRIAL REGISTRATION

PROSPERO CRD42021232469.

Steroid, ascorbic acid, and thiamine in adults with sepsis and septic shock: a systematic review and component network meta-analysis

To assess the effect from individual component in combinations of steroid, ascorbic acid, and thiamine on outcomes in adults with sepsis and septic shock with component network meta-analysis (NMA). We searched PubMed, EMBASE, and the Cochrane Library Central Register of Controlled Trials from 1980 to March 2021 for randomized controlled trials (RCT) that studied the use of glucocorticoid, fludrocortisone, ascorbic acid, and thiamine in patients with sepsis and septic shock. Citations screening, study selection, data extraction, and risk of bias assessment were independently performed by two authors. The primary outcome was short-term mortality. Secondary outcomes were longer-term mortality, time to resolution of shock and duration of mechanical ventilation. Thirty-three RCTs including 9898 patients presented on short-term mortality. In additive component NMA, patients on ascorbic acid alone (RR 0.74, 95% CI 0.57-0.97) or the combination of glucocorticoid and fludrocortisone (RR 0.89, 95% CI 0.80-0.99) had lower short-term mortality, but only the latter was associated with improved long-term mortality (RR 0.89, 95% CI 0.82-0.98). The use of glucocorticoid or the combination of glucocorticoid, ascorbic acid and thiamine hastened resolution of shock. Component NMA showed glucocorticoid (MD - 0.96, 95% CI - 1.61 to - 0.30) but not ascorbic acid or thiamine shortened the time to resolution of shock. Glucocorticoid shortened the duration of mechanical ventilation (MD - 1.48, 95% CI - 2.43 to - 0.52). In adults with sepsis and septic shock, the combination of glucocorticoid and fludrocortisone improved short-term and longer-term mortality. Glucocorticoid shortened the time to resolution of shock and duration of mechanical ventilation. There was no strong evidence supporting the routine use of thiamine and ascorbic acid, but they were associated with minimal adverse effects.