Assessment of metal and organic pollutants in combination with stable isotope analysis in tunas from the Gulf of Cadiz (east Atlantic)

Bioaccumulation patterns of heavy metals (Pb, Cd, Cr, Ni, Fe and Cu) and organic (priority and emerging) pollutants, in combination with stable isotope analysis (SIA), were assessed in muscle and liver of three tuna species from the Gulf of Cadiz (Atlantic bluefin tuna, Thunnus thynnus; Atlantic bonito, Sarda sarda, and skipjack tuna, Katsuwonus pelamis). SIA and contaminant (heavy metal and organic) profiles separately discriminated between species. There was no significant overlap between the trophic niches estimated from isotopic data, suggesting that there are diet differences which may determine differential bioaccumulation patterns. The levels of heavy metals and persistent organic pollutants in muscle of all the individuals analyzed were below the allowable limits established by the current legislation. Concentrations of most contaminants were higher in liver than in muscle, underlining the powerful detoxifying capacity of the liver in tunas. In addition to diet, other factors such as size and age (exposure time to environmental chemicals) explain differences in pollutant accumulation patterns in tissues between species, each with varying degrees of involvement depending on the pollutant class. Our results show that combining contaminant profile data with trophic features based on SIA may help understand pollutant bioaccumulation patterns in upper levels of marine food webs.

Early parenting interventions to prevent internalising problems in children and adolescents: a global systematic review and network meta-analysis

QUESTION

We compared the effectiveness of different types of parenting interventions based on an a priori taxonomy, and the impact of waitlists versus treatment as usual (TAU), in reducing child internalising problems.

STUDY SELECTION AND ANALYSIS

We conducted a systematic review and network meta-analysis of published and unpublished randomised controlled trials (RCTs) until 1 October 2022 that investigated parenting interventions with children younger than 4 years.

EXCLUSION CRITERIA

studies with children born preterm, with intellectual disabilities, or families receiving support for current abuse, neglect, and substance misuse. We assessed the certainty of evidence using the Confidence in Network Meta-Analysis framework. We used random-effects network meta-analysis to estimate standardised mean differences (SMDs) with 95% credible intervals (CrIs).

FINDINGS

Of 20 520 citations identified, 59 RCTs (18 349 participants) were eligible for the network meta-analysis. Parenting interventions focusing on the dyadic relationship (SMD: -0.26, 95% CrI: -0.43 to -0.08) and those with mixed focus (-0.09, -0.17 to -0.02) were more effective in reducing internalising problems than TAU at the first time point available. All interventions were more effective than waitlist, which increased the risk of internalising problems compared with TAU (0.36, 0.19 to 0.52). All effects attenuated at later follow-ups. Most studies were rated as with 'high risk' or 'some concerns' using the Risk of Bias Assessment Tool V.2. There was no strong evidence of effect modification by theoretically informed components or modifiers.

CONCLUSIONS

We found preliminary evidence that relationship-focused and mixed parenting interventions were effective in reducing child internalising problems, and the waitlist comparator increased internalising problems with implications for waiting times between referral and support. Considering the high risk of bias of most studies included, the findings from this meta-analysis should be interpreted with caution. PROSPERO registration number CRD42020172251.

Improvement of Advanced Sample Preparation Systems for the Determination of Trace Ni in Seawater by Electro-Membranes

Due to its important environmental role, the analysis of trace metals in natural waters is attracting increasing attention; consequently, faster and more accurate analytical methods are now needed to reach even lower limits of detection. In this work, we propose the use of electro-membrane extraction (EME) to improve analytical methods based on hollow fiber liquid phase micro-extraction (HFLPME). Specifically, an EME-based method for the determination of trace Ni in seawater has been developed, using an HFLPME system with di-2-ethylhexyl phosphoric acid (DEHPA) in kerosene as a chemical carrier, followed by instrumental determination by graphite furnace atomic absorption spectroscopy (GFAAS). Under optimum conditions, Ni was pre-concentrated 180 ± 17 times after 15 min, using sample pH = 5.5, the concentration of DEHPA 0.9 M in the liquid membranes, and 1.9 M HNO₃ in the acceptor solution, as well as an electric potential of 25 V with the sample being stirred at 500 rpm. When compared with other HFLPME systems for pre-concentration of trace Ni in seawater in the absence of electric potential, the enrichment factor was improved 2.2 times, while the time of extraction was reduced an 89%. The limit of detection of the new method was 23.3 ng L^-1, and both its applicability and accuracy were successfully evaluated by analyzing Ni concentration in a seawater-certified reference material (BCR-403), showing the reliability of EME for sample preparation in the determination of trace metals in marine water samples.

Overviews of Reviews: Concept and Development

BACKGROUND

In the last years, overviews of systematic reviews, or umbrella reviews, have seen a dramatic increase in their use. An overview aims to provide a summary of the included reviews and will often examine research questions beyond those addressed in the systematic reviews being synthesised. The purpose of this article is to provide some recommendations on how overviews should be conducted and reported.

METHOD

A literature review was performed to identify relevant papers on both methodological and applied overviews.

RESULTS

The current literature recommends carrying out overviews by following similar steps to those of systematic reviews: (a) Defining the overview research question; (b) inclusion and exclusion criteria; (c) literature search; (d) data extraction; (e) assessment of risk of bias and reporting quality; (f) overview results; and (g) reporting the overview. Of special interest is how to address dependencies between the systematic reviews.

CONCLUSIONS

Overviews allow evidence to be efficiently combined from multiple systematic reviews. This offers the possibility of translating and summarizing large amounts of information. As in primary studies and systematic reviews, conducting and reporting of overviews must meet appropriate quality standards.

Smoking cessation medicines and e-cigarettes: a systematic review, network meta-analysis and cost-effectiveness analysis

BACKGROUND

Cigarette smoking is one of the leading causes of early death. Varenicline [Champix (UK), Pfizer Europe MA EEIG, Brussels, Belgium; or Chantix (USA), Pfizer Inc., Mission, KS, USA], bupropion (Zyban; GlaxoSmithKline, Brentford, UK) and nicotine replacement therapy are licensed aids for quitting smoking in the UK. Although not licensed, e-cigarettes may also be used in English smoking cessation services. Concerns have been raised about the safety of these medicines and e-cigarettes.

OBJECTIVES

To determine the clinical effectiveness, safety and cost-effectiveness of smoking cessation medicines and e-cigarettes.

DESIGN

Systematic reviews, network meta-analyses and cost-effectiveness analysis informed by the network meta-analysis results.

SETTING

Primary care practices, hospitals, clinics, universities, workplaces, nursing or residential homes.

PARTICIPANTS

Smokers aged ≥ 18 years of all ethnicities using UK-licensed smoking cessation therapies and/or e-cigarettes.

INTERVENTIONS

Varenicline, bupropion and nicotine replacement therapy as monotherapies and in combination treatments at standard, low or high dose, combination nicotine replacement therapy and e-cigarette monotherapies.

MAIN OUTCOME MEASURES

Effectiveness - continuous or sustained abstinence. Safety - serious adverse events, major adverse cardiovascular events and major adverse neuropsychiatric events.

DATA SOURCES

Ten databases, reference lists of relevant research articles and previous reviews. Searches were performed from inception until 16 March 2017 and updated on 19 February 2019.

REVIEW METHODS

Three reviewers screened the search results. Data were extracted and risk of bias was assessed by one reviewer and checked by the other reviewers. Network meta-analyses were conducted for effectiveness and safety outcomes. Cost-effectiveness was evaluated using an amended version of the Benefits of Smoking Cessation on Outcomes model.

RESULTS

Most monotherapies and combination treatments were more effective than placebo at achieving sustained abstinence. Varenicline standard plus nicotine replacement therapy standard (odds ratio 5.75, 95% credible interval 2.27 to 14.90) was ranked first for sustained abstinence, followed by e-cigarette low (odds ratio 3.22, 95% credible interval 0.97 to 12.60), although these estimates have high uncertainty. We found effect modification for counselling and dependence, with a higher proportion of smokers who received counselling achieving sustained abstinence than those who did not receive counselling, and higher odds of sustained abstinence among participants with higher average dependence scores. We found that bupropion standard increased odds of serious adverse events compared with placebo (odds ratio 1.27, 95% credible interval 1.04 to 1.58). There were no differences between interventions in terms of major adverse cardiovascular events. There was evidence of increased odds of major adverse neuropsychiatric events for smokers randomised to varenicline standard compared with those randomised to bupropion standard (odds ratio 1.43, 95% credible interval 1.02 to 2.09). There was a high level of uncertainty about the most cost-effective intervention, although all were cost-effective compared with nicotine replacement therapy low at the £20,000 per quality-adjusted life-year threshold. E-cigarette low appeared to be most cost-effective in the base case, followed by varenicline standard plus nicotine replacement therapy standard. When the impact of major adverse neuropsychiatric events was excluded, varenicline standard plus nicotine replacement therapy standard was most cost-effective, followed by varenicline low plus nicotine replacement therapy standard. When limited to licensed interventions in the UK, nicotine replacement therapy standard was most cost-effective, followed by varenicline standard.

LIMITATIONS

Comparisons between active interventions were informed almost exclusively by indirect evidence. Findings were imprecise because of the small numbers of adverse events identified.

CONCLUSIONS

Combined therapies of medicines are among the most clinically effective, safe and cost-effective treatment options for smokers. Although the combined therapy of nicotine replacement therapy and varenicline at standard doses was the most effective treatment, this is currently unlicensed for use in the UK.

FUTURE WORK

Researchers should examine the use of these treatments alongside counselling and continue investigating the long-term effectiveness and safety of e-cigarettes for smoking cessation compared with active interventions such as nicotine replacement therapy.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016041302.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 59. See the NIHR Journals Library website for further project information.

Examining how meta-analytic methods perform in the presence of bias: A simulation study

Standard meta-analysis methods are vulnerable to bias from incomplete reporting of results (both publication and outcome reporting bias) and poor study quality. Several alternative methods have been proposed as being less vulnerable to such biases. To evaluate these claims independently we simulated study results under a broad range of conditions first with no bias, then introducing simulated publication bias, outcome reporting bias, and bias from poor study quality. We then implemented common and the proposed bias robust meta-analysis methods and compared the mean bias and mean squared error (MSE) for four estimates of effect and the coverage probability of seven confidence intervals. We found that no methods perform well in the presence of any substantial bias. A regression based extension to Egger's test gave an estimate of effect with lower mean bias than standard methods in the presence of publication bias or poor study quality, but had a substantially worse MSE except in very specific conditions. Coverage of all 95% confidence intervals was very poor with increasing numbers of studies in biased conditions, often falling below 50%. The Knapp-Hartung interval performed closest to nominal coverage with fewer than 10 studies in most conditions, and the Henmi-Copas interval generally performed best with more than 10 studies. There was no evidence that a multiplicative term for heterogeneity improved coverage. Multiple forms of bias remain problematic for all meta-analysis methods, with very poor performance under conceivable conditions.

School-based interventions to prevent anxiety, depression and conduct disorder in children and young people: a systematic review and network meta-analysis

Background

Schools in the UK increasingly have to respond to anxiety, depression and conduct disorder as key causes of morbidity in children and young people.

Objective

The objective was to assess the comparative effectiveness of educational setting-based interventions for the prevention of anxiety, depression and conduct disorder in children and young people.

Design

This study comprised a systematic review, a network meta-analysis and an economic evaluation.

Data sources

The databases MEDLINE, EMBASE™ (Elsevier, Amsterdam, the Netherlands), PsycInfo® (American Psychological Association, Washington, DC, USA) and Cochrane Central Register of Controlled Trials (CENTRAL) were searched to 4 April 2018, and the NHS Economic Evaluation Database (NHS EED) was searched on 22 May 2019 for economic evaluations. No language or date filters were applied.

Main outcomes

The main outcomes were post-intervention self-reported anxiety, depression or conduct disorder symptoms.

Review methods

Randomised/quasi-randomised trials of universal or targeted interventions for the prevention of anxiety, depression or conduct disorder in children and young people aged 4–18 years were included. Screening was conducted independently by two reviewers. Data extraction was conducted by one reviewer and checked by a second. Intervention- and component-level network meta-analyses were conducted in OpenBUGS. A review of the economic literature and a cost–consequence analysis were conducted.

Results

A total of 142 studies were included in the review, and 109 contributed to the network meta-analysis. Of the 109 studies, 57 were rated as having an unclear risk of bias for random sequence generation and allocation concealment. Heterogeneity was moderate. In universal secondary school settings, mindfulness/relaxation interventions [standardised mean difference (SMD) –0.65, 95% credible interval (CrI) –1.14 to –0.19] and cognitive–behavioural interventions (SMD –0.15, 95% CrI –0.34 to 0.04) may be effective for anxiety. Cognitive–behavioural interventions incorporating a psychoeducation component may be effective (SMD –0.30, 95% CrI –0.59 to –0.01) at preventing anxiety immediately post intervention. There was evidence that exercise was effective in preventing anxiety in targeted secondary school settings (SMD –0.47, 95% CrI –0.86 to –0.09). There was weak evidence that cognitive–behavioural interventions may prevent anxiety in universal (SMD –0.07, 95% CrI –0.23 to 0.05) and targeted (SMD –0.38, 95% CrI –0.84 to 0.07) primary school settings. There was weak evidence that cognitive–behavioural (SMD –0.04, 95% CrI –0.16 to 0.07) and cognitive–behavioural + interpersonal therapy (SMD –0.18, 95% CrI –0.46 to 0.08) may be effective in preventing depression in universal secondary school settings. Third-wave (SMD –0.35, 95% CrI –0.70 to 0.00) and cognitive–behavioural interventions (SMD –0.11, 95% CrI –0.28 to 0.05) incorporating a psychoeducation component may be effective at preventing depression immediately post intervention. There was no evidence of intervention effectiveness in targeted secondary, targeted primary or universal primary school settings post intervention. The results for university settings were unreliable because of inconsistency in the network meta-analysis. A narrative summary was reported for five conduct disorder prevention studies, all in primary school settings. None reported the primary outcome at the primary post-intervention time point. The economic evidence review reported heterogeneous findings from six studies. Taking the perspective of a single school budget and based on cognitive–behavioural therapy intervention costs in universal secondary school settings, the cost–consequence analysis estimated an intervention cost of £43 per student.

Limitations

The emphasis on disorder-specific prevention excluded broader mental health interventions and restricted the number of eligible conduct disorder prevention studies. Restricting the study to interventions delivered in the educational setting may have limited the number of eligible university-level interventions.

Conclusions

There was weak evidence of the effectiveness of school-based, disorder-specific prevention interventions, although effects were modest and the evidence not robust. Cognitive–behavioural therapy-based interventions may be more effective if they include a psychoeducation component.

Future work

Future trials for prevention of anxiety and depression should evaluate cognitive–behavioural interventions with and without a psychoeducation component, and include mindfulness/relaxation or exercise comparators, with sufficient follow-up. Cost implications must be adequately measured.

Study registration

This study is registered as PROSPERO CRD42016048184.

Funding

This project was funded by the National Institute for Health Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 9, No. 8. See the NIHR Journals Library website for further project information.

Cost-Effectiveness Analysis of Smoking Cessation Interventions in the United Kingdom Accounting for Major Neuropsychiatric Adverse Events

OBJECTIVES

Smoking is a leading cause of death worldwide. Cessation aids include varenicline, bupropion, nicotine replacement therapy (NRT), and e-cigarettes at various doses (low, standard and high) and used alone or in combination with each other. Previous cost-effectiveness analyses have not fully accounted for adverse effects nor compared all cessation aids. The objective was to determine the relative cost-effectiveness of cessation aids in the United Kingdom.

METHODS

An established Markov cohort model was adapted to incorporate health outcomes and costs due to depression and self-harm associated with cessation aids, alongside other health events. Relative efficacy in terms of abstinence and major adverse neuropsychiatric events was informed by a systematic review and network meta-analysis. Base case results are reported for UK-licensed interventions only. Two sensitivity analyses are reported, one including unlicensed interventions and another comparing all cessation aids but removing the impact of depression and self-harm. The sensitivity of conclusions to model inputs was assessed by calculating the expected value of partial perfect information.

RESULTS

When limited to UK-licensed interventions, varenicline standard-dose and NRT standard-dose were most cost-effective. Including unlicensed interventions, e-cigarette low-dose appeared most cost-effective followed by varenicline standard-dose + bupropion standard-dose combined. When the impact of depression and self-harm was excluded, varenicline standard-dose + NRT standard-dose was most cost-effective, followed by varenicline low-dose + NRT standard-dose.

CONCLUSION

Although found to be most cost-effective, combined therapy is currently unlicensed in the United Kingdom and the safety of e-cigarettes remains uncertain. The value-of-information analysis suggested researchers should continue to investigate the long-term effectiveness and safety outcomes of e-cigarettes in studies with active comparators.

Depressive symptoms and academic achievement in UK adolescents: a cross-lagged analysis with genetic covariates

BACKGROUND

The relationship between adolescent depressive symptoms and academic achievement remains poorly understood. The aim of this study was to help clarify the nature and directionality of this association.

METHODS

We used a sample of 13,599 British adolescents (main sample of N=3,809 participants). We fitted cross-lagged panel models using four repeated measures of self-reported depressive symptoms and four measures of academic achievement based on British national records between 11-18 years, separately for male and female adolescents and considering polygenic risk scores (PRS) for educational attainment and depression, alongside other child and parental covariates.

RESULTS

We found evidence of an overall negative association that was stronger in boys (R=-0.21, 95% CI -0.31 to -0.11) than in girls (-0.13, -0.31 to 0.05). Higher depressive symptoms were associated with lower academic achievement at a later stage up to the end of compulsory education (16 years), when the direction of the association reversed, although girls with lower achievement also appeared vulnerable to depressive symptoms at previous stages. The genetic variables derived for this study showed stronger associations for academic achievement, but the PRS for depression also showed a negative association with academic achievement in girls. Child intelligence quotient and peer victimization also showed relevant associations.

LIMITATIONS

Observational design, variation around measurement times, missing data.

CONCLUSIONS

Depressive symptoms and academic achievement should be considered jointly when designing school-based programmes for children and adolescents, alongside gender, child ability and school experience. Including genetic information in research can help to disentangle average from time-varying effects.

Treatment interventions to maintain abstinence from alcohol in primary care: systematic review and network meta-analysis

OBJECTIVE

To determine the most effective interventions in recently detoxified, alcohol dependent patients for implementation in primary care.

DESIGN

Systematic review and network meta-analysis.

DATA SOURCES

Medline, Embase, PsycINFO, Cochrane CENTRAL, ClinicalTrials.gov, and the World Health Organization's International Clinical Trials Registry Platform.

STUDY SELECTION

Randomised controlled trials comparing two or more interventions that could be used in primary care. The population was patients with alcohol dependency diagnosed by standardised clinical tools and who became detoxified within four weeks.

DATA EXTRACTION

Outcomes of interest were continuous abstinence from alcohol (effectiveness) and all cause dropouts (as a proxy for acceptability) at least 12 weeks after start of intervention.

RESULTS

64 trials (43 interventions) were included. The median probability of abstinence across placebo arms was 25%. Compared with placebo, the only intervention associated with increased probability of abstinence and moderate certainty evidence was acamprosate (odds ratio 1.86, 95% confidence interval 1.49 to 2.33, corresponding to an absolute probability of 38%). Of the 62 included trials that reported all cause dropouts, interventions associated with a reduced number of dropouts compared with placebo (probability 50%) and moderate certainty of evidence were acamprosate (0.73, 0.62 to 0.86; 42%), naltrexone (0.70, 0.50 to 0.98; 41%), and acamprosate-naltrexone (0.30, 0.13 to 0.67; 17%). Acamprosate was the only intervention associated with moderate confidence in the evidence of effectiveness and acceptability up to 12 months. It is uncertain whether other interventions can help maintain abstinence and reduce dropouts because of low confidence in the evidence.

CONCLUSIONS

Evidence is lacking for benefit from interventions that could be implemented in primary care settings for alcohol abstinence, other than for acamprosate. More evidence from high quality randomised controlled trials is needed, as are strategies using combined interventions (combinations of drug interventions or drug and psychosocial interventions) to improve treatment of alcohol dependency in primary care.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016049779.

Childhood adversity and self-poisoning: A hospital case control study in Sri Lanka

INTRODUCTION

Adverse childhood experiences (ACE) have been recognized as an important risk factor for suicidal behaviour among adults, but evidence from low and middle-income countries is lacking. This study explored associations between ACE and hospital admission due to non-fatal self-poisoning in Sri Lanka.

METHODS

This was a case-control study. Adults admitted to a tertiary care hospital for medical management of self-poisoning were included as cases, and age and sex matched controls were recruited from the outpatient department. ACE were measured using the World Health Organization's Childhood Adversity Scale. Logistic regression models adjusting for age, sex, ethnicity, and religion were used to quantify the association between ACE and self-poisoning.

RESULTS

The study included 235 cases and 451 controls. Cases were 2.5 times (95% CI 1.8, 3.6) more likely to report an ACE than controls and had higher ACE scores. Childhood physical abuse (OR 4.7, 95% CI 1.2, 19.0) and emotional abuse or neglect (OR 3.7, 95% CI 1.3, 10.1, and 3.7, 95% CI 2.3, 6.0 respectively), increased the risk of self-poisoning in adulthood, as did witnessing household violence (OR 2.2, 95% CI 1.4, 3.4), growing up in a household with a mentally ill or suicidal household member (OR 2.1, 95% CI 1.2, 3.4), and experiencing parental death/separation/divorce (OR 3.1, 95% CI 2.0, 4.9) as a child.

CONCLUSIONS

Reducing exposures to ACEs should be a priority for prevention of suicide and self-harm in Sri Lanka. Innovative methods to increase support for children facing adversity should be explored.

Protocol for a systematic review and network meta-analysis of randomised controlled trials examining the effectiveness of early parenting interventions in preventing internalising problems in children and adolescents

BACKGROUND

Internalising problems, such as depression and anxiety, are common and represent an important economical and societal burden. The effectiveness of parenting interventions in reducing the risk of internalising problems in children and adolescents has not yet been summarised. The aims of this review are to assess the effectiveness of parenting interventions in the primary, secondary and tertiary prevention of internalising problems in children and adolescents and to determine which intervention components and which intervention aspects are most effective for reducing the risk of internalising problems in children and adolescents.

METHODS

Electronic searches in OVID SP versions of MEDLINE, EMBASE and PsycINFO; Cochrane Central Register of Controlled Trials; EBSCO version of ERIC and ClinicalTrials.gov have been performed to identify randomised controlled trials or quasi-randomised controlled trials of parenting interventions. At least two independent researchers will assess studies for inclusion and extract data from each paper. The risk of bias assessment will be conducted independently by two reviewers using the Cochrane Collaboration's Risk of Bias Assessment Tool. Statistical heterogeneity is anticipated given potential variation in participant characteristics, intervention type and mode of delivery, and outcome measures. Random effects models, assuming a common between-study variability, will be used to account for statistical heterogeneity. Results will be analysed using a network meta-analysis (NMA). If appropriate, we will also conduct a component-level NMA, where the 'active ingredients' of interventions are modelled using a network meta-regression approach.

DISCUSSION

Preventing and reducing internalising problems could have major beneficial effects at the economic and societal level. Informing policy makers on the effectiveness of parenting interventions and on which intervention's component is driving the effect is important for the development of treatment strategies.

SYSTEMATIC REVIEW REGISTRATION

International Prospective Register for Systematic Reviews (PROSPERO) number CRD42020172251.

A Critical Study of the Effect of Polymeric Fibers on the Performance of Supported Liquid Membranes in Sample Microextraction for Metals Analysis

Popularity of hollow fiber-supported liquid membranes (HF-SLM) for liquid-phase microextraction (HF-LPME) has increased in the last decades. In particular, HF-SLM are applied for sample treatment in the determination and speciation of metals. Up to the date, optimization of preconcentration systems has been focused on chemical conditions. However, criteria about fiber selection are not reflected in published works. HFs differ in pore size, porosity, wall thickness, etc., which can affect efficiency and/or selectivity of chemical systems in extraction of metals. In this work, Ag+ transport using tri-isobutylphosphine sulfide (TIBPS) has been used as a model to evaluate differences in metal transport due to the properties of three different fibers. Accurel PP 50/280 fibers, with a higher effective surface and smaller wall thickness, showed the highest efficiency for metal transport. Accurel PP Q3/2 exhibited intermediate efficiency but easier handling and, finally, Accurel PP S6/2 fibers, with a higher wall thickness, offered poorer efficiency but the highest stability and capability for metal speciation. Summarizing, selection of the polymeric support of HF-SLM is a key factor in their applicability of LPME for metals in natural waters.

Selective solvent bar micro-extraction as a single-step approach for the measurement of Cu fractions in seawater

Hollow fibre-supported liquid membrane was used for Cu fractionation in marine waters, using di-2-pyridylketone benzoylhydrazone (dPKBH) as a carrier due to its capacity to transport dissolved inorganic Cu at natural seawater pH. Optimized conditions were dPKBH (0.5 mmol L^-1), HNO₃ (0.5 mol L^-1) as acceptor agent, extraction time of 120 min and stirring speed of 800 rpm. Additionally, the selectivity of the method for the extraction of the inorganic Cu fraction was validated by comparing the experimental results with theoretical data, and a mathematical model was obtained for estimation of Cu linked to dissolved organic matter. The method was applied for the measurement of Cu fractions in real seawater samples. Results were successfully compared with the reference material BCR 403 and recovery analysis in waters from the Gulf of Cádiz, showing that it could be used as a simple approach for the study of different Cu fractions in marine waters. Graphical abstract.

Trajectories of depressive symptoms and adult educational and employment outcomes

BACKGROUND

Depressive symptoms show different trajectories throughout childhood and adolescence that may have different consequences for adult outcomes.

AIMS

To examine trajectories of childhood depressive symptoms and their association with education and employment outcomes in early adulthood.

METHOD

We estimated latent trajectory classes from participants with repeated measures of self-reported depressive symptoms between 11 and 24 years of age and examined their association with two distal outcomes: university degree and those not in employment, education or training at age 24.

RESULTS

Our main analyses (n = 9399) yielded five heterogenous trajectories of depressive symptoms. The largest group found (70.5% of participants) had a stable trajectory of low depressive symptoms (stable-low). The other four groups had symptom profiles that reached full-threshold levels at different developmental stages and for different durations. We identified the following groups: childhood-limited (5.1% of participants) with full-threshold symptoms at ages 11-13; childhood-persistent (3.5%) with full-threshold symptoms at ages 13-24; adolescent onset (9.4%) with full-threshold symptoms at ages 17-19; and early-adult onset (11.6%) with full-threshold symptoms at ages 22-24. Relative to the majority 'stable-low' group, the other four groups all exhibited higher risks of one or both adult outcomes.

CONCLUSIONS

Accurate identification of depressive symptom trajectories requires data spanning the period from early adolescence to early adulthood. Consideration of changes in, as well as levels of, depressive symptoms could improve the targeting of preventative interventions in early-to-mid adolescence.

School-based interventions to prevent anxiety and depression in children and young people: a systematic review and network meta-analysis

BACKGROUND

Rates of anxiety and depression are increasing among children and young people. Recent policies have focused on primary prevention of mental disorders in children and young people, with schools at the forefront of implementation. There is limited information for the comparative effectiveness of the multiple interventions available.

METHODS

We did a systematic review and network meta-analysis, searching MEDLINE, Embase, PsycINFO, and Cochrane Central Register of Controlled trials for published and unpublished, passive and active-controlled randomised and quasi-randomised trials. We included educational setting-based, universal, or targeted interventions in which the primary aim was the prevention of anxiety and depression in children and young people aged 4-18 years. Primary outcomes were post-intervention self-report anxiety and depression, wellbeing, suicidal ideation, or self-harm. We assessed risk of bias following the Cochrane Handbook for Systematic Reviews of Interventions. We estimated standardised mean differences (SMD) using random effects network meta-analysis in a Bayesian framework. The study is registered with PROPSERO, number CRD42016048184.

FINDINGS

1512 full-text articles were independently screened for inclusion by two reviewers, from which 137 studies of 56 620 participants were included. 20 studies were assessed as being at low risk of bias for both random sequence generation and allocation concealment. There was weak evidence to suggest that cognitive behavioural interventions might reduce anxiety in primary and secondary settings. In universal secondary settings, mindfulness and relaxation-based interventions showed a reduction in anxiety symptoms relative to usual curriculum (SMD -0·65, 95% credible interval -1·14 to -0·19). There was a lack of evidence to support any one type of intervention being effective to prevent depression in universal or targeted primary or secondary settings. Comparison-adjusted funnel plots suggest the presence of small-study effects for the universal secondary anxiety analysis. Network meta-analysis was not feasible for wellbeing or suicidal ideation or self-harm outcomes, and results are reported narratively.

INTERPRETATION

Considering unclear risk of bias and probable small study effects for anxiety, we conclude there is little evidence that educational setting-based interventions focused solely on the prevention of depression or anxiety are effective. Future research could consider multilevel, systems-based interventions as an alternative to the downstream interventions considered here.

FUNDING

UK National Institute for Health Research.

The process and delivery of CBT for depression in adults: a systematic review and network meta-analysis

Cognitive-behavioural therapy (CBT) is an effective treatment for depressed adults. CBT interventions are complex, as they include multiple content components and can be delivered in different ways. We compared the effectiveness of different types of therapy, different components and combinations of components and aspects of delivery used in CBT interventions for adult depression. We conducted a systematic review of randomised controlled trials in adults with a primary diagnosis of depression, which included a CBT intervention. Outcomes were pooled using a component-level network meta-analysis. Our primary analysis classified interventions according to the type of therapy and delivery mode. We also fitted more advanced models to examine the effectiveness of each content component or combination of components. We included 91 studies and found strong evidence that CBT interventions yielded a larger short-term decrease in depression scores compared to treatment-as-usual, with a standardised difference in mean change of -1.11 (95% credible interval -1.62 to -0.60) for face-to-face CBT, -1.06 (-2.05 to -0.08) for hybrid CBT, and -0.59 (-1.20 to 0.02) for multimedia CBT, whereas wait list control showed a detrimental effect of 0.72 (0.09 to 1.35). We found no evidence of specific effects of any content components or combinations of components. Technology is increasingly used in the context of CBT interventions for depression. Multimedia and hybrid CBT might be as effective as face-to-face CBT, although results need to be interpreted cautiously. The effectiveness of specific combinations of content components and delivery formats remain unclear. Wait list controls should be avoided if possible.

Genetic and Environmental Risk Factors Associated With Trajectories of Depression Symptoms From Adolescence to Young Adulthood

Importance

Less favorable trajectories of depressive mood from adolescence to early adulthood are associated with current and later psychopathology, impaired educational attainment, and social dysfunction, yet the genetic and environmental risk factors associated with these trajectories are not fully established. Examining what risk factors are associated with different trajectories of depressive mood could help identify the nature of depression symptoms and improve preventive interventions for those at most risk.

Objective

To examine the differential associations of genetic and environmental risk factors with trajectories of depression symptoms among individuals observed from ages 10 to 24 years.

Design, Setting, and Participants

In a longitudinal cohort study established in 1990 and currently ongoing (the Avon Longitudinal Study of Parents and Children [ALSPAC]), growth mixture modeling was used to identify trajectories of depression symptoms in 9394 individuals in the United Kingdom. Associations of different risk factors with these trajectories were then examined. Analysis was conducted between August 2018 and January 2019.

Main Outcomes and Measures

Trajectories were composed from depression symptoms measured using the Short Mood and Feelings Questionnaire at 9 occasions from ages 10 to 24 years. Risk factors included sex, a polygenic risk score taken from a recent genome-wide association study of depression symptoms, maternal postnatal depression, partner cruelty to the offspring's mother when the child was aged 2 to 4 years, childhood anxiety at age 8 years, and being bullied at age 10 years.

Results

Data on all risk factors, confounders, and the outcome were available for 3525 individuals, including 1771 (50.2%) who were female. Trajectories were assessed between the mean (SD) age of 10.7 (0.3) years and mean (SD) age of 23.8 (0.5) years. Overall, 5 distinct trajectories of depression symptoms were identified: (1) stable low (2506 individuals [71.1%]), (2) adolescent limited (325 individuals [9.2%]), (3) childhood limited (203 individuals [5.8%]), (4) early-adult onset (393 individuals [11.1%]), and (5) childhood persistent (98 individuals [2.8%]). Of all the associations of risk factors with trajectories, sex (odds ratio [OR], 6.45; 95% CI, 2.89-14.38), the polygenic risk score for depression symptoms (OR, 1.47; 95% CI, 1.10-1.96), and childhood anxiety (OR, 1.30; 95% CI, 1.16-1.45) showed the strongest association with the childhood-persistent trajectory of depression symptoms compared with the stable-low trajectory. Maternal postnatal depression (OR, 2.39; 95% CI, 1.41-4.07) had the strongest association with the early-adult-onset trajectory, while partner cruelty to mother (OR, 2.30; 95% CI, 1.36-3.90) had the strongest association with the adolescent-limited trajectory. Bullying (OR, 8.08; 95% CI, 4.92-13.26) showed the strongest association with the childhood-limited trajectory.

Conclusions and Relevance

The least favorable trajectories of depression symptoms (childhood persistent and early-adult onset) were associated with both genetic and environmental risk factors, but the 2 trajectories of limited duration that had resolved by early adulthood (childhood limited and adolescent limited) were not associated with the polygenic risk score or maternal postnatal depression. Bullying was strongly associated with both the childhood-persistent and childhood-limited trajectories, suggesting that this risk factor may have a time-specific effect. These findings suggest that examining genetic and multiple time-specific environmental antecedents could help identify trajectories of varying onset and chronicity.

Multi-elemental ionic liquid-based solvent bar micro-extraction of priority and emerging trace metallic pollutants (Cd, Ag, Pd) in natural waters

Transition metals Cd, Pd and Ag are toxic even at very low concentration. Cd is considered a priority substance; while, Pd and Ag are emerging pollutants. Membrane technologies have been applied for their extraction; however, they require important amounts of reagents, time and energy. Additionally, effective reagents for metal extraction in saline natural waters are limited. In this case, hollow fiber liquid phase micro-extraction with a configuration of solvent bar (SBME) using the ionic liquid Cyphos® 101 as extractant is proposed. Optimized conditions for SBME of Cd, Ag and Pd were 50% Cyphos® 101 in the organic solution, extraction time 30 min and 800 rpm stirring rate. Leaching was in all cases lower than 0.1%. Metallic concentrations were measured by flame atomic absorption spectroscopy. The method was applied to the extraction of Ag, Cd and Pd in natural water samples. Except for waste water, Pd extraction was higher than 90% in all cases. Cd (≈100%) and Ag (93-95%) offered their best results for saline samples. Concluding, the proposed system is a low cost and green methodology that allows a simple and fast extraction of trace pollutants such as Ag, Cd and Pd in different natural waters, including highly saline samples.

Selection bias introduced by informative censoring in studies examining effects of vaccination in infancy

Background

Many studies have examined ‘non-specific’ vaccine effects on infant mortality: attention has been particularly drawn to diphtheria-tetanus-pertussis (DTP) vaccine, which has been proposed to be associated with an increased mortality risk. Both right and left censoring are common in such studies.

Methods

We conducted simulation studies examining right censoring (at measles vaccination) and left censoring (by excluding early follow-up) in a variety of scenarios in which confounding was and was not present. We estimated both unadjusted and adjusted hazard ratios (HRs), averaged across simulations.

Results

We identified scenarios in which right-censoring at measles vaccination was informative and so introduced bias in the direction of a detrimental effect of DTP vaccine. In some, but not all, situations, adjusting for confounding by health status removed the bias caused by censoring. However, such adjustment will not always remove bias due to informative censoring: inverse probability weighting was required in one scenario. Bias due to left censoring arose when both health status and DTP vaccination were associated with mortality during the censored early follow-up and was in the direction of attenuating a beneficial effect of DTP on mortality. Such bias was more severe when the effect of DTP changed over time.

Conclusions

Estimates of non-specific effects of vaccines may be biased by informative right or left censoring. Authors of studies estimating such effects should consider the potential for such bias and use appropriate statistical approaches to control for it. Such approaches require measurement of prognostic factors that predict censoring.

Choice of Prosthetic Implant Combinations in Total Hip Replacement: Cost-Effectiveness Analysis Using UK and Swedish Hip Joint Registries Data

BACKGROUND

Prosthetic implants used in total hip replacements (THR) have a range of bearing surface combinations (metal-on-polyethylene, ceramic-on-polyethylene, ceramic-on-ceramic, and metal-on-metal), head sizes (small [<36 mm in diameter] and large [≥36 mm in diameter]), and fixation techniques (cemented, uncemented, hybrid, and reverse hybrid). These can influence prosthesis survival, patients' quality of life, and healthcare costs.

OBJECTIVES

To compare the lifetime cost-effectiveness of implants for patients of different age and sex profiles.

METHODS

We developed a Markov model to compare the cost-effectiveness of various implants against small-head cemented metal-on-polyethylene implants. The probability that patients required 1 or more revision surgeries was estimated from analyses of more than 1 million patients in the UK and Swedish hip joint registries, for men and women younger than 55, 55 to 64, 65 to 74, 75 to 84, and 85 years and older. Implant and healthcare costs were estimated from local procurement prices, national tariffs, and the literature. Quality-adjusted life-years were calculated using published utility estimates for patients undergoing THR in the United Kingdom.

RESULTS

Small-head cemented metal-on-polyethylene implants were the most cost-effective for men and women older than 65 years. These findings were robust to sensitivity analyses. Small-head cemented ceramic-on-polyethylene implants were most cost-effective in men and women younger than 65 years, but these results were more uncertain.

CONCLUSIONS

The older the patient group, the more likely that the cheapest implants, small-head cemented metal-on-polyethylene implants, were cost-effective. We found no evidence that uncemented, hybrid, or reverse hybrid implants were the most cost-effective option for any patient group. Our findings can influence clinical practice and procurement decisions for healthcare payers worldwide.

Selective ionic liquid solvent bar micro-extraction for estimation of ultra-trace silver fractions in marine waters

Ag can be found in the ocean at the ultra-trace level, mainly as AgCl_n^(n-1)- and complexed by dissolved organic matter (Ag-DOM). However, methods for studying Ag speciation in marine waters are limited by the lack of extractants capable to separate organic and inorganic silver species in natural conditions of seawater samples. In this work, a two-phase solvent bar micro-extraction method using the ionic liquid trihexyltetradecylphosphonium chloride (Cyphos® 101) was applied for selective micro-extraction of AgCl_n^(n-1)- from organic silver in marine waters, working at seawater pH,. The application to real samples was performed under the following conditions: 2.5% Cyphos® 101 in kerosene solution with 10% dodecan-1-ol inside the fiber, and 30 min of sample extraction at a stirring rate of 800 rpm. The proposed SBME was successfully used for estimation of Ag fractions in waters from the Bay of Cádiz (South-west Spain) showing its applicability for a simple, fast and environmentally friendly speciation of silver in marine water samples. The method presented a linear response up to 500 ng L^-1 and a detection limit of 0.4 ng L^-1, using GF-AAS for instrumental determination.

Synthesising quantitative evidence in systematic reviews of complex health interventions

Public health and health service interventions are typically complex: they are multifaceted, with impacts at multiple levels and on multiple stakeholders. Systematic reviews evaluating the effects of complex health interventions can be challenging to conduct. This paper is part of a special series of papers considering these challenges particularly in the context of WHO guideline development. We outline established and innovative methods for synthesising quantitative evidence within a systematic review of a complex intervention, including considerations of the complexity of the system into which the intervention is introduced. We describe methods in three broad areas: non-quantitative approaches, including tabulation, narrative and graphical approaches; standard meta-analysis methods, including meta-regression to investigate study-level moderators of effect; and advanced synthesis methods, in which models allow exploration of intervention components, investigation of both moderators and mediators, examination of mechanisms, and exploration of complexities of the system. We offer guidance on the choice of approach that might be taken by people collating evidence in support of guideline development, and emphasise that the appropriate methods will depend on the purpose of the synthesis, the similarity of the studies included in the review, the level of detail available from the studies, the nature of the results reported in the studies, the expertise of the synthesis team and the resources available.

Solvent Bar Micro-Extraction of Heavy Metals from Natural Water Samples Using 3-Hydroxy-2-Naphthoate-Based Ionic Liquids

Developments in the liquid micro-extraction of trace metals from aqueous phases have proven to be limited when extended from pure water to more complex and demanding matrices such as sea water or wastewater treatment effluents. To establish a system that works under such matrices, we successfully tested three task-specific ionic liquids, namely trihexyltetradecyl- phosphonium-, methyltrioctylphosphonium- and methyltrioctylammonium 3-hydroxy-2-naphthoate in two-phase solvent bar micro-extraction (SBME) experiments. We describe the influence of pH, organic additives, time, stirring rate and volume of ionic liquid for multi-elemental micro-extraction of Cu, Ag, Cd and Pb from various synthetic and natural aqueous feed solutions. Highest extraction for all metals was achieved at pH 8.0. Minimal leaching of the ionic liquids into the aqueous phase was demonstrated, with values < 30 mg L⁻¹ DOC in all cases. Sample salinities of up to 60 g L⁻¹ NaCl had a positive effect on the extraction of Cd, possibly due to an efficient extraction mechanism of the present chlorido complexes. In metal-spiked natural feed solutions, the selected SBME setups showed unchanged stability under all conditions tested. We could efficiently (≥85%) extract Cu and Ag from drinking water and achieved high efficacies for Ag and Cd from natural sea water and hypersaline water, respectively. The method presented here proves to be a useful tool for an efficient SBME of heavy metals from natural waters without the need to pretreat or modify the sample.

The effects of changes to the built environment on the mental health and well-being of adults: Systematic review

There is increasing interest in the influence of place on health, and the need to distinguish between environmental and individual level factors. For environmental-level factors, current evidence tends to show associations through cross-sectional and uncontrolled longitudinal analyses rather than through more robust study designs that can provide stronger causal evidence. We restricted this systematic review to randomised (or cluster) randomised controlled trials and controlled before-and-after studies of changes to the built environment. Date of search was December 2016. We identified 14 studies. No evidence was found of an effect on mental health from 'urban regeneration' and 'improving green infrastructure' studies. Beneficial effects on quality-of-life outcomes from 'improving green infrastructure' were found in two studies. One 'improving green infrastructure' study reported an improvement in social isolation. Risk-of-bias assessment indicated robust data from only four studies. Overall, evidence for the impact of built environment interventions on mental health and quality-of-life is weak. Future research requires more robust study designs and interdisciplinary research involving public health, planning and urban design experts.

Differences in cognitive, motivational and contextual variables between under-achieving, normally-achieving, and over-achieving students: A mixed-effects analysis

BACKGROUND

There are few studies in Spain which analyze the influence of individual, motivational and contextual variables, which might be different between underachieving, normally achieving and overachieving students.

METHOD

A total of 1,398 Spanish high school students participated. Mixed-effects models were used to analyze data.

RESULTS

The results showed some evidence of: (a) Partial mediational effect of self-concept on the association between cognitive ability and academic achievement. (b) Higher levels of learning goals in the overachieving group than in the underachieving group, but no differences in achievement and reinforcement goals between groups. (c) Positive effect of learning strategies on attainment, both in the underachieving and the non-underachieving students. (d) Little effect of context variables on academic achievement, both in the underachieving and non-underachieving students.

CONCLUSIONS

underachieving students seem to employ all the learning strategies considered to a lesser extent than normally and overachieving students. They also have a lower level of learning goals. On the contrary, overachieving students score more highly than under and normally achieving students in almost all of the above factors.

Dealing with effect size multiplicity in systematic reviews and meta-analyses

Systematic reviews often encounter primary studies that report multiple effect sizes based on data from the same participants. These have the potential to introduce statistical dependency into the meta-analytic data set. In this paper, we provide a tutorial on dealing with effect size multiplicity within studies in the context of meta-analyses of intervention and association studies, recommending a three-step approach. The first step is to define the research question and consider the extent to which it mainly reflects interest in mean effect sizes (which we term a convergent approach) or an interest in exploring heterogeneity (which we term a divergent approach). A second step is to identify the types of multiplicities that appear in the initial database of effect sizes relevant to the research question, and we propose a categorization scheme to differentiate them. The third step is to select a strategy for dealing with each type of multiplicity. The researcher can choose between a reductionist meta-analytic approach, which is characterized by inclusion of a single effect size per study, and an integrative approach, characterized by inclusion of multiple effect sizes per study. We present an overview of available analysis strategies for dealing with effect size multiplicity within studies and provide recommendations intended to help researchers decide which strategy might be preferable in particular situations. Last, we offer caveats and cautions about addressing the challenges multiplicity poses for systematic reviews and meta-analyses.

Mortality After Total Knee Arthroplasty: A Systematic Review of Incidence, Temporal Trends, and Risk Factors

BACKGROUND

The capacity for total knee arthroplasty to improve pain, quality of life, and functional outcomes is widely recognized. Postoperative mortality is rare but of paramount importance, and needs to be accurately quantified and conveyed to patients in order to support decision-making prior to surgery. The purpose of this study was to determine a contemporary estimate of the risk of mortality following total knee arthroplasty, including the identification of temporal trends, common causes, and modifiable and nonmodifiable risk factors.

METHODS

We performed a systematic review with searches of MEDLINE, AMED, CAB Abstracts, and Embase. Studies in any language published from 2006 to 2016 reporting 30 or 90-day mortality following total knee arthroplasty were included, supplemented by contact with authors. Meta-analysis and meta-regression were performed for quantitative data.

RESULTS

Thirty-seven studies with mortality data from 15 different countries following over 1.75 million total knee arthroplasties formed the basis of this review. The pooled Poisson-normal random-effects meta-analysis estimates of 30 and 90-day mortality were 0.20% (95% confidence interval [CI], 0.17% to 0.24%) and 0.39% (95% CI, 0.32% to 0.49%). Both estimates have fallen over the 10-year study period (p < 0.001). Meta-regression using the median year of surgery as a moderator showed that 30 and 90-day mortality following total knee arthroplasty fell to 0.10% (95% CI, 0.07% to 0.14%) and 0.19% (95% CI, 0.15% to 0.23%), respectively, in 2015. The leading cause of death was cardiovascular disease.

CONCLUSIONS

There is an ongoing worldwide temporal decline in mortality following total knee arthroplasty. Improved patient selection and perioperative care and a healthy-population effect may account for this observation. Efforts to further reduce mortality should be targeted primarily at reducing cardiovascular events following total knee arthroplasty.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Novel 3-Hydroxy-2-Naphthoate-Based Task-Specific Ionic Liquids for an Efficient Extraction of Heavy Metals

Ionic liquids (ILs) are per definition salts with melting points below 100°C and might be green alternatives for the extraction of heavy metals from aqueous solutions due to their favorable environmental and physico-chemical properties. Partial solution during extraction, so-called leaching, however, limits their applicability. The present study synthesizes three novel ammonium and phosphonium ILs based on 3-hydroxy-2-naphthoic acid-trihexyltetradecylphosphonium-([P66614]), methyltrioctylphosphonium-([P1888]), and methyltrioctylammonium 3-hydroxy-2-naphthoate ([N1888][HNA])-by a deprotonation-metathesis route. The aims were to improve stability during extraction while still achieving high selectivity toward heavy metal ions, as well as to study the impact of different alkyl chains and the central atom of the cation on physico-chemical properties, extraction efficacy, and leaching. Extraction capabilities for the seven heavy metals Ag, Cd, Co, Cu, Mn, Ni, and Pb were studied in pure water at pH 8.0. Further experiments were conducted in water containing 30 g L-1 NaCl to simulate a seawater matrix and/or 30 mg L-1 humic acids, as well as metal-spiked natural water samples. All three ILs showed extraction efficacies ≥90% for Cu and Pb after 24 h. Overall, extraction efficacies for Ag, Cd, Cu, and Pb were highest for drinking water samples. Ag and Cd extraction was increased by up to 41% in (hyper-) saline samples using IL [P66614][HNA] compared with pure water samples. Leaching values were reduced down to 0.07% loss of the applied IL, which can be attributed to the hydrophobic character of 3-hydroxy-2-naphthoate. Our results represent a positive development toward a greener extraction of heavy metals from natural waters.

Ionic liquid solvent bar micro-extraction of CdCln(n-2)- species for ultra-trace Cd determination in seawater

Water analysis of trace metals has been benefited by recent studies on sample preparation by liquid micro-extraction. However, there are still limitations for its application to seawater, such as the need of additives to preserve the sample or the availability of chemical extractants for the selective extraction from highly saline samples. In this work, a three phase solvent bar micro-extraction (3SBME) system containing the ionic liquid trioctylmethylammonium chloride (Aliquat^® 336) has been used for isolation and pre-concentration of Cd from seawater samples, due to its ability for ionic exchange of CdCl_n^(n-2)-. The system was optimized to work at the natural pH of seawater, and conditions for application to real samples were 0.18 M Aliquat^® 336 dissolved in kerosene with 0.25 M dodecan-1-ol as organic solution, 1.5 M HNO₃ as acceptor solution, 60 min extraction time, and 800 rpm stirring speed in the sample. Loss of organic solution into the sample during extraction was evaluated and revealed its dependence on stirring rate and extraction time. Under optimum conditions samples containing Cd 0.09-0.90 nM were pre-concentrated 65 times. GF-AAS was used for metal quantification with a limit of detection of 0.04 nM. Accuracy was successfully evaluated measuring Cd in a seawater certified reference material BCR-403.

Computer-Based Training in Math and Working Memory Improves Cognitive Skills and Academic Achievement in Primary School Children: Behavioral Results

Student academic achievement has been positively related to further development outcomes, such as the attainment of higher educational, employment, and socioeconomic aspirations. Among all the academic competences, mathematics has been identified as an essential skill in the field of international leadership as well as for those seeking positions in disciplines related to science, technology, and engineering. Given its positive consequences, studies have designed trainings to enhance children's mathematical skills. Additionally, the ability to regulate and control actions and cognitions, i.e., executive functions (EF), has been associated with school success, which has resulted in a strong effort to develop EF training programs to improve students' EF and academic achievement. The present study examined the efficacy of a school computer-based training composed of two components, namely, working memory and mathematics tasks. Among the advantages of using a computer-based training program is the ease with which it can be implemented in school settings and the ease by which the difficulty of the tasks can be adapted to fit the child's ability level. To test the effects of the training, children's cognitive skills (EF and IQ) and their school achievement (math and language grades and abilities) were evaluated. The results revealed a significant improvement in cognitive skills, such as non-verbal IQ and inhibition, and better school performance in math and reading among the children who participated in the training compared to those children who did not. Most of the improvements were related to training on WM tasks. These findings confirmed the efficacy of a computer-based training that combined WM and mathematics activities as part of the school routines based on the training's impact on children's academic competences and cognitive skills.

Oral anticoagulants for prevention of stroke in atrial fibrillation: systematic review, network meta-analysis, and cost effectiveness analysis

Objective To compare the efficacy, safety, and cost effectiveness of direct acting oral anticoagulants (DOACs) for patients with atrial fibrillation.Design Systematic review, network meta-analysis, and cost effectiveness analysis. Data sources Medline, PreMedline, Embase, and The Cochrane Library.Eligibility criteria for selecting studies Published randomised trials evaluating the use of a DOAC, vitamin K antagonist, or antiplatelet drug for prevention of stroke in patients with atrial fibrillation.Results 23 randomised trials involving 94 656 patients were analysed: 13 compared a DOAC with warfarin dosed to achieve a target INR of 2.0-3.0. Apixaban 5 mg twice daily (odds ratio 0.79, 95% confidence interval 0.66 to 0.94), dabigatran 150 mg twice daily (0.65, 0.52 to 0.81), edoxaban 60 mg once daily (0.86, 0.74 to 1.01), and rivaroxaban 20 mg once daily (0.88, 0.74 to 1.03) reduced the risk of stroke or systemic embolism compared with warfarin. The risk of stroke or systemic embolism was higher with edoxaban 60 mg once daily (1.33, 1.02 to 1.75) and rivaroxaban 20 mg once daily (1.35, 1.03 to 1.78) than with dabigatran 150 mg twice daily. The risk of all-cause mortality was lower with all DOACs than with warfarin. Apixaban 5 mg twice daily (0.71, 0.61 to 0.81), dabigatran 110 mg twice daily (0.80, 0.69 to 0.93), edoxaban 30 mg once daily (0.46, 0.40 to 0.54), and edoxaban 60 mg once daily (0.78, 0.69 to 0.90) reduced the risk of major bleeding compared with warfarin. The risk of major bleeding was higher with dabigatran 150 mg twice daily than apixaban 5 mg twice daily (1.33, 1.09 to 1.62), rivaroxaban 20 mg twice daily than apixaban 5 mg twice daily (1.45, 1.19 to 1.78), and rivaroxaban 20 mg twice daily than edoxaban 60 mg once daily (1.31, 1.07 to 1.59). The risk of intracranial bleeding was substantially lower for most DOACs compared with warfarin, whereas the risk of gastrointestinal bleeding was higher with some DOACs than warfarin. Apixaban 5 mg twice daily was ranked the highest for most outcomes, and was cost effective compared with warfarin.Conclusions The network meta-analysis informs the choice of DOACs for prevention of stroke in patients with atrial fibrillation. Several DOACs are of net benefit compared with warfarin. A trial directly comparing DOACs would overcome the need for indirect comparisons to be made through network meta-analysis.Systematic review registration PROSPERO CRD 42013005324.

Solvent bar micro-extraction (SBME) based determination of PAHs in seawater samples

Measuring the impact of PAHs in seawater samples is often difficult due to the low concentrations in which they appear and the complexity of the sample matrix. Traditional methods for sample preparation such as liquid-liquid extraction and solid phase extraction require the use of excessive amounts of solvents and reagents, and sample handling. In this work, hollow fiber liquid phase micro-extraction (HFLPME), in the configuration of solvent bar micro-extraction (SBME), was proposed as an environmentally friendly and more effective tool, for the extraction of the 16 priority PAHs from seawater samples. Extraction was conducted using hexane as a solvent. Enrichment factors from 45 to 163 were obtained after 60min at a stirring rate of 500rpm in the sample. Moreover, a negative linear relationship was observed between the enrichment factor and the molecular weight of the PAHs. Under optimized conditions, the limits of detection were in the range from 0.21 to 0.82ngL^-1, the method showed a linear response up to 500μgL^-1, and the average relative standard deviation for seawater samples spiked with 5ngL^-1 was 11.6%. After calibration, the SBME was applied to extract PAHs in seawater samples from the Bay of Cadiz (SW Spain), showing an average recovery of 99%. In conclusion, the SBME is an environmentally friendly, one-step alternative for sample preparation in the determination of PAHs in seawater samples.

Choice of implant combinations in total hip replacement: systematic review and network meta-analysis

Objective To compare the survival of different implant combinations for primary total hip replacement (THR). Design Systematic review and network meta-analysis. Data sources Medline, Embase, The Cochrane Library, ClinicalTrials.gov, WHO International Clinical Trials Registry Platform, and the EU Clinical Trials Register.Review methods Published randomised controlled trials comparing different implant combinations. Implant combinations were defined by bearing surface materials (metal-on-polyethylene, ceramic-on-polyethylene, ceramic-on-ceramic, or metal-on-metal), head size (large ≥36 mm or small <36 mm), and fixation technique (cemented, uncemented, hybrid, or reverse hybrid). Our reference implant combination was metal-on-polyethylene (not highly cross linked), small head, and cemented. The primary outcome was revision surgery at 0-2 years and 2-10 years after primary THR. The secondary outcome was the Harris hip score reported by clinicians.Results 77 studies were included in the systematic review, and 15 studies (3177 hips) in the network meta-analysis for revision. There was no evidence that the risk of revision surgery was reduced by other implant combinations compared with the reference implant combination. Although estimates are imprecise, metal-on-metal, small head, cemented implants (hazard ratio 4.4, 95% credible interval 1.6 to 16.6) and resurfacing (12.1, 2.1 to 120.3) increase the risk of revision at 0-2 years after primary THR compared with the reference implant combination. Similar results were observed for the 2-10 years period. 31 studies (2888 patients) were included in the analysis of Harris hip score. No implant combination had a better score than the reference implant combination.Conclusions Newer implant combinations were not found to be better than the reference implant combination (metal-on-polyethylene (not highly cross linked), small head, cemented) in terms of risk of revision surgery or Harris hip score. Metal-on-metal, small head, cemented implants and resurfacing increased the risk of revision surgery compared with the reference implant combination. The results were consistent with observational evidence and were replicated in sensitivity analysis but were limited by poor reporting across studies.Systematic review registration PROSPERO CRD42015019435.

Therapeutic interventions for alcohol dependence in non-inpatient settings: a systematic review and network meta-analysis (protocol)

BACKGROUND

Alcohol dependence is common and serious cause of social and physical harm. However, the optimal management of those with moderate and severe alcohol dependence in primary and community care after detoxification remains unclear. The aim of this review is to evaluate the effectiveness of interventions for maintaining abstinence in people with alcohol dependence following detoxification.

METHODS

We will systematically search electronic databases and clinical trial registries for randomized controlled trials (RCTs) examining the effectiveness of pharmacological and/or psychosocial interventions for maintaining abstinence in recently detoxified, alcohol-dependent adults. The searches will be complemented by checking references and citations from included studies and other relevant systematic reviews. No limitation on language, year, or publication status will be applied. RCTs will be selected using prespecified criteria. Descriptive information, study characteristics, and results of eligible RCTs will be extracted. A revised version of the Cochrane Risk of Bias tool (RoB 2.0) will be used to assess the risk of bias in eligible RCTs. Results will be synthesized and analyzed using network meta-analysis (NMA). Overall strength of the evidence and publication bias will be evaluated. Subgroup and sensitivity analysis will also be performed.

DISCUSSION

This network meta-analysis aims to appraise and summarize the total evidence of therapeutic interventions for alcohol-dependent patients that require support for detoxification and can be treated in the community. The evidence will determine which combination of interventions are most promising for current practice and further investigation.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016049779.

Corticosteroids in septic shock: a systematic review and network meta-analysis

Background

Multiple corticosteroids and treatment regimens have been used as adjuncts in the treatment of septic shock. Qualitative and quantitative differences exist at cellular and tissular levels between the different drugs and their patterns of delivery. The objective of this study was to elucidate any differences between the drugs and their treatment regimens regarding outcomes for corticosteroid use in adult patients with septic shock.

Methods

Network meta-analysis of the data used for the recently conducted Cochrane review was performed. Studies that included children and were designed to assess respiratory function in pneumonia and acute respiratory distress syndrome, as well as cross-over studies, were excluded. Network plots were created for each outcome, and all analyses were conducted using a frequentist approach assuming a random-effects model.

Results

Complete data from 22 studies and partial data from 1 study were included. Network meta-analysis provided no clear evidence that any intervention or treatment regimen is better than any other across the spectrum of outcomes. There was strong evidence of differential efficacy in only one area: shock reversal. Hydrocortisone boluses and infusions were more likely than methylprednisolone boluses and placebo to result in shock reversal.

Conclusions

There was no clear evidence that any one corticosteroid drug or treatment regimen is more likely to be effective in reducing mortality or reducing the incidence of gastrointestinal bleeding or superinfection in septic shock. Hydrocortisone delivered as a bolus or as an infusion was more likely than placebo and methylprednisolone to result in shock reversal.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-017-1659-4) contains supplementary material, which is available to authorized users.

Indirect evidence of reporting biases was found in a survey of medical research studies

OBJECTIVES

To explore indirect evidence of reporting biases by examining the distribution of P-values reported in published medical articles and to compare P-values distributions across different contexts.

STUDY DESIGN AND SETTING

We selected a random sample (N = 1,500) of articles published in PubMed in March 2014. We extracted information on study type, design, medical discipline, and P-values for the first reported outcome and primary outcome (if specified) from each article. We plotted the P-values transformed to the z-score scale and used caliper tests to investigate threshold effects.

RESULTS

Out of the 1,500 randomly selected records, 758 (50.5%) were included. We retrieved or calculated 758 P-values for first reported outcomes and 389 for primary outcomes (specified in only 51% of included studies). The first reported and the primary outcome differed in 28% (110/389) of the included studies. The distributions of P-values for first reported outcomes and primary outcomes showed a notable discontinuity at the common thresholds of statistical significance (P-value = 0.05 and P-value = 0.01). We also found marked discontinuities in the distributions of z-scores across various medical disciplines, study designs, and types.

CONCLUSION

Reporting biases are still common in medical research. We discuss their implications, strategies to detect them, and recommended practices to avoid them.

Association of BCG, DTP, and measles containing vaccines with childhood mortality: systematic review

OBJECTIVES

 To evaluate the effects on non-specific and all cause mortality, in children under 5, of Bacillus Calmette-Guérin (BCG), diphtheria-tetanus-pertussis (DTP), and standard titre measles containing vaccines (MCV); to examine internal validity of the studies; and to examine any modifying effects of sex, age, vaccine sequence, and co-administration of vitamin A.

DESIGN

 Systematic review, including assessment of risk of bias, and meta-analyses of similar studies.

STUDY ELIGIBILITY CRITERIA

 Clinical trials, cohort studies, and case-control studies of the effects on mortality of BCG, whole cell DTP, and standard titre MCV in children under 5.

DATA SOURCES

 Searches of Medline, Embase, Global Index Medicus, and the WHO International Clinical Trials Registry Platform, supplemented by contact with experts in the field. To avoid overlap in children studied across the included articles, findings from non-overlapping birth cohorts were identified.

RESULTS

 Results from 34 birth cohorts were identified. Most evidence was from observational studies, with some from short term clinical trials. Most studies reported on all cause (rather than non-specific) mortality. Receipt of BCG vaccine was associated with a reduction in all cause mortality: the average relative risks were 0.70 (95% confidence interval 0.49 to 1.01) from five clinical trials and 0.47 (0.32 to 0.69) from nine observational studies at high risk of bias. Receipt of DTP (almost always with oral polio vaccine) was associated with a possible increase in all cause mortality on average (relative risk 1.38, 0.92 to 2.08) from 10 studies at high risk of bias; this effect seemed stronger in girls than in boys. Receipt of standard titre MCV was associated with a reduction in all cause mortality (relative risks 0.74 (0.51 to 1.07) from four clinical trials and 0.51 (0.42 to 0.63) from 18 observational studies at high risk of bias); this effect seemed stronger in girls than in boys. Seven observational studies, assessed as being at high risk of bias, have compared sequences of vaccines; results of a subset of these suggest that administering DTP with or after MCV may be associated with higher mortality than administering it before MCV.

CONCLUSIONS

 Evidence suggests that receipt of BCG and MCV reduce overall mortality by more than would be expected through their effects on the diseases they prevent, and receipt of DTP may be associated with an increase in all cause mortality. Although efforts should be made to ensure that all children are immunised on schedule with BCG, DTP, and MCV, randomised trials are needed to compare the effects of different sequences.

Solvent bar micro-extraction with graphite atomic absorption spectrometry for the determination of silver in ocean water

Main drawbacks for silver determination in seawater are the effects of samples matrix and that Ag appears in the sub ng L(-1). Available methods for sample preparation in Ag analysis are based on solid and liquid extraction using tedious process that increase the cost of analysis and the risk of sample contamination, producing important waste amounts. Solvent bar micro-extraction (SBME) allows the pre-concentration of Ag in a micro-volume of the ionic liquid Aliquat 336® in kerosene solution. For this reason, it is considered as a green alternative to standard methods. The method has been optimized using synthetic seawater samples, offering the highest response for samples at pH=2, using 5% Aliquat 336® dissolved in kerosene containing 5% dodecan-1-ol as acceptor solution and after 1h stirring at 800rpm. The method exhibited linearity up to 50ngL(-1), with a limit of detection of 0.09ngL(-1), covering the concentration range of interest for environmental studies. Finally, it was applied for determination of Ag in real seawater samples, and the results were compared with the reference method of liquid-liquid extraction with 1-pyrrolidine-dithiocarbamate and diethylammonium-diethyldithiocarbamate, showing the applicability of ionic liquid based SBME using Aliquat 336(®) for the simple monitoring of silver ultra-traces in seawater analysis.

Simplification of iron speciation in wine samples: a spectrophotometric approach

A simple direct spectrophotometric method was developed for the analysis of Fe(II) and total Fe in wine samples. This method is based on the formation of an Fe(II) complex with 2,2'-dipyridylketone picolinoylhydrazone (DPKPH), which shows a maximum green-blue absorption (λ = 700 nm) at pH 4.9. Operative conditions for the batch procedure were investigated including reagent concentration, buffer solutions, and wavelength. The tolerance limits of foreign ions and sample matrix have been also evaluated. Limits of detection and quantification were 0.005 and 0.017 mg L(-1) of Fe(II), respectively, allowing its determination in real wine samples. Finally, the proposed method was used in the analysis of white, rose, and red wines. Results were compared with a reference method of Commission Regulation (ECC) No. 2676/90 of September 1990 determining European Community methods for the analysis of wines for Fe analysis, showing the reliability of the proposed method in Fe analysis in wine samples.

Multi-way analysis for decadal pollution trends assessment: the Guadalquivir River estuary as a case study

Alongside history, human activities have contributed to the deployment of environmental quality. In particular, during the last decades the problem of water preservation has gained increasing attention. Statistical analysis is essential to analyze environmental data and to identify trends of pollutants over space and time. Usually applied techniques for data treatment are based on the organization of data in a two-way array, missing some shades on pollutants distribution. This fact supports the use of multi-way techniques, which allow the analysis of the results through different directions at the same time. For Three Modes Principal Components Analysis (3MPCA) a principal components analysis is conducted using three modes and a "core" matrix that allows assessing their interactions. In the case of environmental studies, it offers information about the spatial-temporal evolution of pollutants in a certain water body. The Guadalquivir River estuary has been used as a model system. It is a representative human influenced system, where different pollution inputs have been characterized. In this study, decadal evolution of pollutants has been discussed, to evaluate among others the effects of EU legislation on river water quality. The aim of this work is the establishment of the evolution, during the last decade, of nutrients and metals ultra-traces distribution in an estuary affected by anthropic activities. As examples, Pb and PO4(3-) show a trend to decrease their weight on water pollution, total suspended solids (TSS) behavior is related with massive rain events, and the rising of new technologies appears as a source of emerging pollutants as Co in urban-industrial areas.

Domain wall manipulation in magnetic nanotubes induced by electric current pulses

We propose that the injection of electric currents can be used to independently manipulate the position and chirality of vortex-like domain walls in metallic ferromagnetic nanotubes. We support this proposal upon theoretical and numerical assessment of the magnetization dynamics driven by such currents. We show that proper interplay between the tube geometry, magnitude of the electric current and the duration of a current pulse, can be used to manipulate the position, velocity and chirality of a vortex domain wall. Our calculations suggest that domain wall velocities greater than 1 km s(-1) can be achieved for tube diameters of the order of 30 nm and increasing with it. We also find that the transition from steady to precessional domain wall motion occurs for very high electric current densities, of the order of 10(13) A m(-2). Furthermore, the great stability displayed by such chiral magnetic configurations, and the reduced Ohmic loses provided by the current pulses, lead to highly reproducible and efficient domain wall reversal mechanisms.

[Methods for averaging alpha coefficients in reliability generalization studies]

The reliability generalization (RG) approach is a kind of meta-analysis that aims to statistically integrate a set of independent reliability coefficients obtained in several applications of a test, with the purpose of characterizing the measurement error and determining which factors related to the studies and samples can explain its variability. Diverse procedures have been proposed in the literature for averaging a set of independent alpha coefficients, and there is no consensus about which methods are best. Here, we present the results of a Monte Carlo simulation study, comparing the performance of twelve procedures proposed in Feldt and Charter, in terms of bias and mean square error. These procedures differ from each other in the transformation (or not) of the coefficients, and in the application or not of a weighting scheme based on sample size. Our results recommend using weighted methods in contrast to unweighted ones, and transforming the coefficients by the Hakstian and Whalen's proposal or by the proposal based on the square root of the inverse alpha coefficient. Lastly, we discuss the relations between the diverse procedures for averaging alpha coefficients with fixed-effects, random-effects, and varying coefficients models.