Can we rely on the best trial? A comparison of individual trials and systematic reviews

Novel functional insights into ischemic stroke biology provided by the first genome-wide association study of stroke in indigenous Africans

BACKGROUND

African ancestry populations have the highest burden of stroke worldwide, yet the genetic basis of stroke in these populations is obscure. The Stroke Investigative Research and Educational Network (SIREN) is a multicenter study involving 16 sites in West Africa. We conducted the first-ever genome-wide association study (GWAS) of stroke in indigenous Africans.

METHODS

Cases were consecutively recruited consenting adults (aged > 18 years) with neuroimaging-confirmed ischemic stroke. Stroke-free controls were ascertained using a locally validated Questionnaire for Verifying Stroke-Free Status. DNA genotyping with the H3Africa array was performed, and following initial quality control, GWAS datasets were imputed into the NIH Trans-Omics for Precision Medicine (TOPMed) release2 from BioData Catalyst. Furthermore, we performed fine-mapping, trans-ethnic meta-analysis, and in silico functional characterization to identify likely causal variants with a functional interpretation.

RESULTS

We observed genome-wide significant (P-value < 5.0E-8) SNPs associations near AADACL2 and miRNA (MIR5186) genes in chromosome 3 after adjusting for hypertension, diabetes, dyslipidemia, and cardiac status in the base model as covariates. SNPs near the miRNA (MIR4458) gene in chromosome 5 were also associated with stroke (P-value < 1.0E-6). The putative genes near AADACL2, MIR5186, and MIR4458 genes were protective and novel. SNPs associations with stroke in chromosome 2 were more than 77 kb from the closest gene LINC01854 and SNPs in chromosome 7 were more than 116 kb to the closest gene LINC01446 (P-value < 1.0E-6). In addition, we observed SNPs in genes STXBP5-AS1 (chromosome 6), GALTN9 (chromosome 12), FANCA (chromosome 16), and DLGAP1 (chromosome 18) (P-value < 1.0E-6). Both genomic regions near genes AADACL2 and MIR4458 remained significant following fine mapping.

CONCLUSIONS

Our findings identify potential roles of regulatory miRNA, intergenic non-coding DNA, and intronic non-coding RNA in the biology of ischemic stroke. These findings reveal new molecular targets that promise to help close the current gaps in accurate African ancestry-based genetic stroke's risk prediction and development of new targeted interventions to prevent or treat stroke.

Opportunities to improve reporting of rapid response in health technology assessment

Introduction

Mini health technology assessment (HTA) reports have been used to support policy makers and health systems by providing a timely summary of scientific evidence. The objective of this meta-epidemiologic study was to evaluate the quality of reporting of mini-HTA reports published in Brazil.

Methods

An electronic search for all mini-HTA reports published between 2014 and March 2019 was conducted in the SISREBRATS and CONITEC databases. The study selection and data extraction were performed by two independent assessors. The following data were extracted: bibliographic data; research question; characteristics of the population, health technologies and outcomes assessed; eligibility criteria; information about searches and study selection; risk of bias assessment; quality of evidence assessment; synthesis of results; and recommendation about the technology evaluated. A descriptive analysis was used to summarize the information retrieved from all the included mini-HTA reports.

Results

We included 103 mini-HTA reports, the great majority of which (92.3 percent) focused on the coverage of the technologies in the healthcare system, with more than 60 percent being about drugs. Only five mini-HTA reports (4.8 percent) gave reasons for the choice of outcomes, and fifteen (14.5 percent) discriminated between primary and secondary outcomes. All mini-HTAs reported the databases searched and 99 percent of them reported using Medline. Sixty percent of the mini-HTA reported assessing the risk of bias, and 52 percent reported assessing the quality of evidence.

Conclusion

The quality of reporting of the mini-HTA reports performed in Brazil is insufficient and needs to be improved to guarantee transparency and replicability.

Non-invasive ventilation versus invasive weaning in critically ill adults: a systematic review and meta-analysis

BACKGROUND

Extubation to non-invasive ventilation (NIV) has been investigated as a strategy to wean critically ill adults from invasive ventilation and reduce ventilator-related complications.

METHODS

We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, proceedings of four conferences and bibliographies (to June 2020) for randomised and quasi-randomised trials that compared extubation with immediate application of NIV to continued invasive weaning in intubated adults and reported mortality (primary outcome) or other outcomes. Two reviewers independently screened citations, assessed trial quality and abstracted data.

RESULTS

We identified 28 trials, of moderate-to-good quality, involving 2066 patients, 44.6% with chronic obstructive pulmonary disease (COPD). Non-invasive weaning significantly reduced mortality (risk ratio (RR) 0.57, 95% CI 0.44 to 0.74; high quality), weaning failures (RR 0.59, 95% CI 0.43 to 0.81; high quality), pneumonia (RR 0.30, 95% CI 0.22 to 0.41; high quality), intensive care unit (ICU) (mean difference (MD) -4.62 days, 95% CI -5.91 to -3.34) and hospital stay (MD -6.29 days, 95% CI -8.90 to -3.68). Non-invasive weaning also significantly reduced the total duration of ventilation, duration of invasive ventilation and duration of ventilation related to weaning (MD -0.57, 95% CI -1.08 to -0.07) and tracheostomy rate. Mortality, pneumonia, reintubation and ICU stay were significantly lower in trials enrolling COPD (vs mixed) populations.

CONCLUSION

Non-invasive weaning significantly reduced mortality, pneumonia and the duration of ventilation related to weaning, particularly in patients with COPD. Beneficial effects are less clear (or more careful patient selection is required) in non-COPD patients.

PROSPERO REGISTRATION NUMBER

CRD42020201402.

Vasopressor and inotrope treatment for septic shock: An umbrella review of reviews

PURPOSE

To review the characteristics, findings and quality of systematic reviews (SRs) on the effect of any vasopressor/inotrope on outcomes in adult patients with sepsis compared with either no treatment, another vasopressor or inotrope or fluids.

MATERIALS AND METHODS

We systematically searched Cochrane Central Register of Controlled Trials, PubMed and Embase (January 1993-March 2021). Descriptive statistics were used.

RESULTS

Among the 28 SRs identified, mortality was the primary outcome in most (26/28) and mortality was usually (23/28) studied using randomised controlled trials (RCTs). Fifteen SRs focused exclusively on patients with sepsis or septic shock. Sepsis and septic shock were always grouped for the analysis. Publication bias was consistently low when studied. The most consistent findings were a survival advantage with norepinephrine versus dopamine, which disappeared in analyses restricted to 28-day mortality, and more arrhythmias with dopamine. However, these analyses were dominated by a single study. Only 2 SRs were judged to be of moderate-high quality. Lack of blinding and attrition bias may have affected the outcomes.

CONCLUSIONS

The quality of SRs on the effect of vasopressors/inotropes on the outcomes of adult patients with sepsis can be improved, but high-quality, multicenter, RCTs should be preferred to additional SRs on this topic.

Developing a fully automated evidence synthesis tool for identifying, assessing and collating the evidence

Evidence synthesis is a key element of evidence-based medicine. However, it is currently hampered by being labour intensive meaning that many trials are not incorporated into robust evidence syntheses and that many are out of date. To overcome this, a variety of techniques are being explored, including using automation technology. Here, we describe a fully automated evidence synthesis system for intervention studies, one that identifies all the relevant evidence, assesses the evidence for reliability and collates it to estimate the relative effectiveness of an intervention. Techniques used include machine learning, natural language processing and rule-based systems. Results are visualised using modern visualisation techniques. We believe this to be the first, publicly available, automated evidence synthesis system: an evidence mapping tool that synthesises evidence on the fly.

Protocol registration issues of systematic review and meta-analysis studies: a survey of global researchers

Background

Although protocol registration of systematic reviews/meta-analysis (SR/MA) is still not mandatory, it is highly recommended that authors publish their SR/MA protocols prior to submitting their manuscripts for publication as recommended by the Cochrane guidelines for conducting SR/MAs. our aim was to assess the awareness, obstacles, and opinions of SR/MA authors about the protocol registration process.

Methods

A cross-sectional survey study included the authors who published SR/MAs during the period from 2010 to 2016, and they were contacted for participation in our survey study. They were identified through the literature search of SR/MAs in Scopus database. An online questionnaire was sent to each participant via e-mail after receiving their approval to join the study. We have sent 6650 emails and received 275 responses.

Results

A total of 270 authors responses were complete and included in the final analysis. Our results has shown that PROSPERO was the most common database used for protocol registration (71.3%). The registration-to-acceptance time interval in PROSPERO was less than 1 month (99.1%). Almost half of the authors (44.2%) did not register their protocols prior to publishing their SR/MAs and according to their opinion that the other authors lack knowledge of protocol importance and mandance to be registered, was the most commonly reported reason (44.9%). A significant percenatge of respondents (37.4%) believed that people would steal their ideas from protocol databases, while only 5.3% reported that their SR/MA had been stolen. However, the majority (72.9%) of participants have agreed that protocol registries play a role in preventing unnecessary duplication of reviews. Finally, 37.4% of participants agree that SR/MA protocol registration should be mandatory.

Conclusion

About half of the participants believes that the main reason for not registering protocols, is that the other authors lack knowledge concerning obligation and importance to register the SR/MA protocols in advance. Therefore, tools should be available to mandate protocol registration of any SRs beforehand and increasing awareness about the benefits of protocol registration among researchers.

Update on evidence in craniomaxillofacial surgery

PURPOSE OF REVIEW

Evidence-based medicine underpins clinical practice. Ideally, our clinical decision-making stems from systematic reviews of randomized controlled trials. However, in practice, this is not often the case, and we must instead rely on the best available evidence.

RECENT FINDINGS

We review the history of evidence-based research, the development of the levels of evidence, and the relationship of evidence and bias present in craniomaxillofacial surgery. We also discuss the recent trends in CMF publications and identify areas for improvement.

SUMMARY

Because of inherent challenges, the quality of evidence in craniomaxillofacial surgery lags behind other surgical and medical specialties. However, over recent years this has improved significantly, with better reporting of data and a higher rate of randomized controlled trials.

Natriuretic peptide-guided treatment for heart failure: a systematic review and meta-analysis

BACKGROUND

GUIDE-IT, the largest trial to date, published in August 2017, evaluating the effectiveness of natriuretic peptide (NP)-guided treatment of heart failure (HF), was stopped early for futility on a composite outcome. However, the reported effect sizes on individual outcomes of all-cause mortality and HF admissions are potentially clinically relevant.

OBJECTIVE

This systematic review and meta-analysis aims to combine all available trial level evidence to determine if NP-guided treatment of HF reduces all-cause mortality and HF admissions in patients with HF.

STUDY SELECTION

Eight databases, no language restrictions, up to November 2017 were searched for all randomised controlled trials comparing NP-guided treatment versus clinical assessment alone in adult patients with HF. No language restrictions were applied. Publications were independently double screened and extracted. Fixed-effect meta-analyses were conducted.

FINDINGS

89 papers were included, reporting 19 trials (4554 participants), average ages 62-80 years. Pooled risk ratio estimates for all-cause mortality (16 trials, 4063 participants) were 0.87, 95% CI 0.77 to 0.99 and 0.80, 95% CI 0.72 to 0.89 for HF admissions (11 trials, 2822 participants). Sensitivity analyses, restricted to low risk of bias, produced similar estimates, but were no longer statistically significant.

CONCLUSIONS

Considering all the evidence to date, the pooled effects suggest that NP-guided treatment is beneficial in reducing HF admissions and all-cause mortality. However, there is still insufficient high-quality evidence to make definitive recommendations on the use of NP-guided treatment in clinical practice.

TRIAL REGISTRATION NUMBER

Systematic Review Cochrane Database Number: CD008966.

Rapid reviews may produce different results to systematic reviews: a meta-epidemiological study

OBJECTIVE

To simulate possible changes in systematic review results if rapid review methods were used.

STUDY DESIGN AND SETTING

We recalculated meta-analyses for binary primary outcomes in Cochrane systematic reviews, simulating rapid review methods. We simulated searching only PubMed, excluding older articles (5, 7, 10, 15, and 20 years before the search date), excluding smaller trials (<50, <100, and <200 participants), and using the largest trial only. We examined percentage changes in pooled odds ratios (ORs) (classed as no important change [<5%], small [<20%], moderate [<30%], or large [≥30%]), statistical significance, and biases observed using rapid methods.

RESULTS

Two thousand five hundred and twelve systematic reviews (16,088 studies) were included. Rapid methods resulted in the loss of all data in 3.7-44.7% of meta-analyses. Searching only PubMed had the smallest risk of changed ORs (19% [477/2,512] were small changes or greater; 10% [260/2,512] were moderate or greater). Changes in ORs varied substantially with each rapid review method; 8.4-21.3% were small, 1.9-8.8% were moderate, and 4.7-34.1% were large. Changes in statistical significance occurred in 6.5-38.6% of meta-analyses. Changes from significant to nonsignificant were most common (2.1-13.7% meta-analyses). We found no evidence of bias with any rapid review method.

CONCLUSION

Searching PubMed only might be considered where a ∼10% risk of the primary outcome OR changing by >20% could be tolerated. This could be the case in scoping reviews, resource limitation, or where syntheses are needed urgently. Other situations, such as clinical guidelines and regulatory decisions, favor more comprehensive systematic review methods.

Rapid reviews may produce different results to systematic reviews: a meta-epidemiological study

Objective

To simulate possible changes in systematic review results if rapid review methods were used.

Study Design and Setting

We recalculated meta-analyses for binary primary outcomes in Cochrane systematic reviews, simulating rapid review methods. We simulated searching only PubMed, excluding older articles (5, 7, 10, 15, and 20 years before the search date), excluding smaller trials (<50, <100, and <200 participants), and using the largest trial only. We examined percentage changes in pooled odds ratios (ORs) (classed as no important change [<5%], small [<20%], moderate [<30%], or large [≥30%]), statistical significance, and biases observed using rapid methods.

Results

Two thousand five hundred and twelve systematic reviews (16,088 studies) were included. Rapid methods resulted in the loss of all data in 3.7–44.7% of meta-analyses. Searching only PubMed had the smallest risk of changed ORs (19% [477/2,512] were small changes or greater; 10% [260/2,512] were moderate or greater). Changes in ORs varied substantially with each rapid review method; 8.4–21.3% were small, 1.9–8.8% were moderate, and 4.7–34.1% were large. Changes in statistical significance occurred in 6.5–38.6% of meta-analyses. Changes from significant to nonsignificant were most common (2.1–13.7% meta-analyses). We found no evidence of bias with any rapid review method.

Conclusion

Searching PubMed only might be considered where a ∼10% risk of the primary outcome OR changing by >20% could be tolerated. This could be the case in scoping reviews, resource limitation, or where syntheses are needed urgently. Other situations, such as clinical guidelines and regulatory decisions, favor more comprehensive systematic review methods.

Assessing the robustness of direct meta-analysis in the presence of heterogeneity

Aim: To assess robustness of findings in recent systematic reviews of atypical antipsychotics in schizophrenia patients in the presence of heterogeneity. Methods: Relative efficacy was measured in seven direct comparisons of mean difference (MD) in average positive and negative syndrome scale total score and comparisons between conventional meta-analysis results and four alternate meta-analytic strategies using the difference in MD (ΔMD). Results: MDs in positive and negative syndrome scale total score were smaller in the conventional meta-analyses than those for three of the four analytic strategies. Such differences were small (all ΔMD <4). No considerable differences in effect size were observed in the limit meta-analysis comparison (|ΔMD| <1). Conclusion: The analyses validated the systematic review results and demonstrate the value of confirmatory sensitivity analysis.

Use of methodological tools for assessing the quality of studies in periodontology and implant dentistry: a systematic review

OBJECTIVE

To evaluate the methodological approaches used to assess the quality of studies included in systematic reviews (SRs) in periodontology and implant dentistry.

MATERIALS & METHODS

Two electronic databases (PubMed and Cochrane Database of Systematic Reviews) were searched independently to identify SRs examining interventions published through 2 September 2013. The reference lists of included SRs and records of 10 specialty dental journals were searched manually. Methodological approaches were assessed using seven criteria based on the Cochrane Handbook for Systematic Reviews of Interventions. Temporal trends in methodological quality were also explored.

RESULTS

Of the 159 SRs with meta-analyses included in the analysis, 44 (28%) reported the use of domain-based tools, 15 (9%) reported the use of checklists and 7 (4%) reported the use of scales. Forty-two (26%) SRs reported use of more than one tool. Criteria were met heterogeneously; authors of 15 (9%) publications incorporated the quality of evidence of primary studies into SRs, whereas 69% of SRs reported methodological approaches in the Materials/Methods section. Reporting of four criteria was significantly better in recent (2010-2013) than in previous publications.

CONCLUSION

The analysis identified several methodological limitations of approaches used to assess evidence in studies included in SRs in periodontology and implant dentistry.

A pragmatic strategy for the review of clinical evidence

BACKGROUND

Systematic reviews (SR) of clinical evidence are rightfully considered the basis for developing recommendations to support decisions in current practice. To avoid bias, SRs are expected to be systematic in their research strategy and are exhaustive. The drawback of the latter criteria relies in the substantial work needed to conduct and keep SRs updated. The objective of this paper is to compare a research strategy based on the review of a selected number of core journals, which we consider a 'pragmatic review' (PR), with that derived by an SR in estimating the efficacy of treatments.

METHODS

Five clinical areas were considered for the comparison between the two strategies: chronic obstructive pulmonary disease, dermatology, heart failure, renal diseases and stroke. We extracted a systematic sample from all the Cochrane SRs pertaining to each area and were published before April 2010. Two groups of journals were considered in the PR: six general journals that commonly published research for the five clinical areas, and five specialist journals with the highest impact factor in each area. To assess the agreement in the findings of SRs and PRs, we considered both the direction of the estimates and P-values.

RESULTS

A sample of 27 SRs included 171 overall analyses and 259 subgroup analyses related to primary outcomes. The PR captured one or more clinical trials in 24 of the 27 SRs (89%), and 118 of the 171 overall analyses (69%) were replicated. The PR supported the recommendations to use (or not) the study treatment in 11 of the 13 SRs (85%), which ended with a clinical recommendation.

CONCLUSIONS

We verified in a sample of SRs that the conclusion of a research strategy based on a pre-defined set of general and specialist medical journals is able to replicate almost all the clinical recommendations of a formal SR.

Glucocorticoids for acute viral bronchiolitis in infants and young children

BACKGROUND

Previous systematic reviews have not shown clear benefit of glucocorticoids for acute viral bronchiolitis, but their use remains considerable. Recent large trials add substantially to current evidence and suggest novel glucocorticoid-including treatment approaches.

OBJECTIVES

To review the efficacy and safety of systemic and inhaled glucocorticoids in children with acute viral bronchiolitis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2012, Issue 12), MEDLINE (1950 to January week 2, 2013), EMBASE (1980 to January 2013), LILACS (1982 to January 2013), Scopus® (1823 to January 2013) and IRAN MedEx (1998 to November 2009).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing short-term systemic or inhaled glucocorticoids versus placebo or another intervention in children under 24 months with acute bronchiolitis (first episode with wheezing). Our primary outcomes were: admissions by days 1 and 7 for outpatient studies; and length of stay (LOS) for inpatient studies. Secondary outcomes included clinical severity parameters, healthcare use, pulmonary function, symptoms, quality of life and harms.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data on study and participant characteristics, interventions and outcomes. We assessed risk of bias and graded strength of evidence. We meta-analysed inpatient and outpatient results separately using random-effects models. We pre-specified subgroup analyses, including the combined use of bronchodilators used in a protocol.

MAIN RESULTS

We included 17 trials (2596 participants); three had low overall risk of bias. Baseline severity, glucocorticoid schemes, comparators and outcomes were heterogeneous. Glucocorticoids did not significantly reduce outpatient admissions by days 1 and 7 when compared to placebo (pooled risk ratios (RRs) 0.92; 95% confidence interval (CI) 0.78 to 1.08 and 0.86; 95% CI 0.7 to 1.06, respectively). There was no benefit in LOS for inpatients (mean difference -0.18 days; 95% CI -0.39 to 0.04). Unadjusted results from a large factorial low risk of bias RCT found combined high-dose systemic dexamethasone and inhaled epinephrine reduced admissions by day 7 (baseline risk of admission 26%; RR 0.65; 95% CI 0.44 to 0.95; number needed to treat 11; 95% CI 7 to 76), with no differences in short-term adverse effects. No other comparisons showed relevant differences in primary outcomes.

AUTHORS' CONCLUSIONS

Current evidence does not support a clinically relevant effect of systemic or inhaled glucocorticoids on admissions or length of hospitalisation. Combined dexamethasone and epinephrine may reduce outpatient admissions, but results are exploratory and safety data limited. Future research should further assess the efficacy, harms and applicability of combined therapy.

Influence of trial sample size on treatment effect estimates: meta-epidemiological study

OBJECTIVE

To assess the influence of trial sample size on treatment effect estimates within meta-analyses.

DESIGN

Meta-epidemiological study.

DATA SOURCES

93 meta-analyses (735 randomised controlled trials) assessing therapeutic interventions with binary outcomes, published in the 10 leading journals of each medical subject category of the Journal Citation Reports or in the Cochrane Database of Systematic Reviews.

DATA EXTRACTION

Sample size, outcome data, and risk of bias extracted from each trial.

DATA SYNTHESIS

Trials within each meta-analysis were sorted by their sample size: using quarters within each meta-analysis (from quarter 1 with 25% of the smallest trials, to quarter 4 with 25% of the largest trials), and using size groups across meta-analyses (ranging from <50 to ≥ 1000 patients). Treatment effects were compared within each meta-analysis between quarters or between size groups by average ratios of odds ratios (where a ratio of odds ratios less than 1 indicates larger effects in smaller trials).

RESULTS

Treatment effect estimates were significantly larger in smaller trials, regardless of sample size. Compared with quarter 4 (which included the largest trials), treatment effects were, on average, 32% larger in trials in quarter 1 (which included the smallest trials; ratio of odds ratios 0.68, 95% confidence interval 0.57 to 0.82), 17% larger in trials in quarter 2 (0.83, 0.75 to 0.91), and 12% larger in trials in quarter 3 (0.88, 0.82 to 0.95). Similar results were obtained when comparing treatment effect estimates between different size groups. Compared with trials of 1000 patients or more, treatment effects were, on average, 48% larger in trials with fewer than 50 patients (0.52, 0.41 to 0.66) and 10% larger in trials with 500-999 patients (0.90, 0.82 to 1.00).

CONCLUSIONS

Treatment effect estimates differed within meta-analyses solely based on trial sample size, with stronger effect estimates seen in small to moderately sized trials than in the largest trials.

Intraocular pressure-lowering effects of commonly used fixed-combination drugs with timolol: a systematic review and meta-analysis

Background

The first goal of medical therapy in glaucoma is to reduce intraocular pressure (IOP), and the fixed-combination medications are needed to achieve sufficiently low target IOP. The aim of this systematic review and meta-analysis is to evaluate IOP-lowering effect of the commonly used fixed-combination drugs containing 0.5% timolol.

Methods

Pertinent publications were identified through systematic searches. Over 85% of the patients had to be diagnosed with primary open-angle glaucoma (POAG) or ocular hypertension (OHT). Forty-one randomized clinical trials were included in the meta-analysis. The main efficacy measures were the absolute and relative values of mean diurnal IOP reduction, and the highest and lowest IOP reductions on the diurnal IOP curve. The pooled 1- to 3-month IOP-lowering effects after a medicine-free washout period was calculated by performing meta-analysis using the random effects model, and relative treatment effects among different fixed combinations were assessed using a mixed-effects meta-regression model.

Results

The relative reductions for mean diurnal IOP were 34.9% for travoprost/timolol, 34.3% for bimatoprost/timolol, 33.9% for latanoprost/timolol, 32.7% for brinzolamide/timolol, 29.9% for dorzolamide/timolol, and 28.1% for brimonidine/timolol. For the highest IOP decrease, relative reductions ranged from 31.3% for dorzolamide/timolol to 35.5% for travoprost/timolol; for the lowest IOP decrease, those varied from 25.9% for dorzolamide/timolol to 33.1% for bimatoprost/timolol. Both latanoprost/timolol and travoprost/timolol were more effective in lowering mean diurnal IOP than brimonidine/timolol (WMD: 5.9 and 7.0) and dorzolamide/timolol (WMD: 3.8 and 3.3).

Conclusions

All six commonly used fixed-combination drugs containing timolol can effectively lower IOP in patients with POAG and OHT, and both latanoprost/timolol and travoprost/timolol might achieve better IOP-lowering effects among the six fixed-combination agents.

Reaching consensus on the physiotherapeutic management of patients following upper abdominal surgery: a pragmatic approach to interpret equivocal evidence

BACKGROUND

Postoperative pulmonary complications remain the most significant cause of morbidity following open upper abdominal surgery despite advances in perioperative care. However, due to the poor quality primary research uncertainty surrounding the value of prophylactic physiotherapy intervention in the management of patients following abdominal surgery persists. The Delphi process has been proposed as a pragmatic methodology to guide clinical practice when evidence is equivocal.

METHODS

The objective was to develop a clinical management algorithm for the post operative management of abdominal surgery patients. Eleven draft algorithm statements extracted from the extant literature by the primary research team were verified and rated by scientist clinicians (n=5) in an electronic three round Delphi process. Algorithm statements which reached a priori defined consensus-semi-interquartile range (SIQR)<0.5-were collated into the algorithm.

RESULTS

The five panelists allocated to the abdominal surgery Delphi panel were from Australia, Canada, Sweden, and South Africa. The 11 draft algorithm statements were edited and 5 additional statements were formulated. The panel reached consensus on the rating of all statements. Four statements were rated essential.

CONCLUSION

An expert Delphi panel interpreted the equivocal evidence for the physiotherapeutic management of patients following upper abdominal surgery. Through a process of consensus a clinical management algorithm was formulated. This algorithm can now be used by clinicians to guide clinical practice in this population.

Robust meta-analytic conclusions mandate the provision of prediction intervals in meta-analysis summaries

OBJECTIVES

Results of meta-analyses typically conclude that future large studies may be mandated. However, the predictive ability of these estimates is deficient. We explored meta-analytic prediction intervals as means for providing a clear and appropriate future treatment summary reflecting current estimates.

STUDY DESIGN

A meta-epidemiological study of binary outcome critical care meta-analyses published between 2002 and 2010. Computation of 95% DerSimonian-Laird and Bayesian random-effects meta-analytic confidence intervals (CI) and 95% credible intervals (CrI), respectively, and frequentist (PI) and Bayesian (PrI) prediction intervals for odds ratio (OR) and risk ratio (RR) were undertaken. Bayesian calculations included the probability that the OR and RR point estimates ≥1.

RESULTS

Seventy-two meta-analyses from 70 articles were identified, containing between three and 80 studies each, with median nine studies. For both frequentist and Bayesian settings, 49-69% of the meta-analyses excluded the null. All significant CrI had high probabilities of efficacy/harm. The number of PI vs. PrI excluding 1 was 25% vs. 3% (OR), 26% vs. 3% (RR) of the total meta-analyses. Unsurprisingly, PI/PrI width was greater than CI/CrI width and increased with increasing heterogeneity and combination of fewer studies.

CONCLUSION

Robust meta-analytic conclusions and determination of studies warranting new large trials may be more appropriately signaled by consideration of initial interval estimates with prediction intervals. Substantial heterogeneity results in exceedingly wide PIs. More caution should be exercised regarding the conclusions of a meta-analysis.

Steroids and bronchodilators for acute bronchiolitis in the first two years of life: systematic review and meta-analysis

OBJECTIVE

To evaluate and compare the efficacy and safety of bronchodilators and steroids, alone or combined, for the acute management of bronchiolitis in children aged less than 2 years.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, Embase, Central, Scopus, PubMed, LILACS, IranMedEx, conference proceedings, and trial registers. Inclusion criteria Randomised controlled trials of children aged 24 months or less with a first episode of bronchiolitis with wheezing comparing any bronchodilator or steroid, alone or combined, with placebo or another intervention (other bronchodilator, other steroid, standard care).

REVIEW METHODS

Two reviewers assessed studies for inclusion and risk of bias and extracted data. Primary outcomes were selected by clinicians a priori based on clinical relevance: rate of admission for outpatients (day 1 and up to day 7) and length of stay for inpatients. Direct meta-analyses were carried out using random effects models. A mixed treatment comparison using a Bayesian network model was used to compare all interventions simultaneously.

RESULTS

48 trials (4897 patients, 13 comparisons) were included. Risk of bias was low in 17% (n = 8), unclear in 52% (n = 25), and high in 31% (n = 15). Only adrenaline (epinephrine) reduced admissions on day 1 (compared with placebo: pooled risk ratio 0.67, 95% confidence interval 0.50 to 0.89; number needed to treat 15, 95% confidence interval 10 to 45 for a baseline risk of 20%; 920 patients). Unadjusted results from a single large trial with low risk of bias showed that combined dexamethasone and adrenaline reduced admissions on day 7 (risk ratio 0.65, 0.44 to 0.95; number needed to treat 11, 7 to 76 for a baseline risk of 26%; 400 patients). A mixed treatment comparison supported adrenaline alone or combined with steroids as the preferred treatments for outpatients (probability of being the best treatment based on admissions at day 1 were 45% and 39%, respectively). The incidence of reported harms did not differ. None of the interventions examined showed clear efficacy for length of stay among inpatients.

CONCLUSIONS

Evidence shows the effectiveness and superiority of adrenaline for outcomes of most clinical relevance among outpatients with acute bronchiolitis, and evidence from a single precise trial for combined adrenaline and dexamethasone.

Glucocorticoids for acute viral bronchiolitis in infants and young children

BACKGROUND

Previous systematic reviews have not shown clear benefit of glucocorticoids for acute viral bronchiolitis, but their use remains considerable. Recent large trials add substantially to current evidence and suggest novel glucocorticoid-including treatment approaches.

OBJECTIVES

To review the efficacy and safety of systemic and inhaled glucocorticoids in children with acute viral bronchiolitis.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2009, issue 4); MEDLINE (1950 to November 2009); EMBASE (1980 to Week 47 2009); LILACS (1982 to November 2009); Scopus® (1823 to November 2009); and IRAN MedEx (1998 to November 2009).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing short-term systemic or inhaled glucocorticoids versus placebo or another intervention in children < 24 months with acute bronchiolitis (first episode with wheezing). Our primary outcomes were: admissions by days 1 and 7 for outpatient studies; and length of stay (LOS) for inpatient studies. Secondary outcomes included clinical severity parameters, healthcare use, pulmonary function, symptoms, quality of life and harms.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data on study and participant characteristics, interventions and outcomes. We assessed risk of bias and graded strength of evidence. Inpatient and outpatient results were meta-analysed separately using random-effects models. We pre-specified subgroup analyses, including the combined use of protocolised bronchodilators.

MAIN RESULTS

We included 17 trials (2596 participants); only two had low overall risk of bias. Baseline severity, glucocorticoid schemes, comparators and outcomes were heterogeneous. Glucocorticoids did not significantly reduce outpatient admissions by days 1 and 7 when compared to placebo (pooled risk ratios (RRs) 0.92; 95% CI 0.78 to 1.08; and 0.86; 95% CI 0.7 to 1.06, respectively). There was no benefit in LOS for inpatients (mean difference -0.18 days; 95% CI -0.39 to 0.04). Unadjusted results from a large factorial low risk of bias RCT found combined high-dose systemic dexamethasone and inhaled epinephrine reduced admissions by day 7 (baseline risk of admission 26%; RR 0.65, 95% CI 0.44 to 0.95; number needed to treat 11, 95% CI 7 to 76), with no differences in short-term adverse effects. No other comparisons showed relevant differences in primary outcomes.

AUTHORS' CONCLUSIONS

Current evidence does not support a clinically relevant effect of systemic or inhaled glucocorticoids on admissions or length of hospitalization. Combined dexamethasone and epinephrine may reduce outpatient admissions, but results are exploratory and safety data limited. Future research should further assess the efficacy, harms and applicability of combined therapy.