Systematic reviews as a tool for planning and interpreting trials

Background Systematic reviews followed by ameta-analysis are carried out in medical research to combine the results of two or more related studies. Stroke trials have struggled to show beneficial effects and meta-analysis should be used more widely throughout the research process to either speed up the development of useful interventions, or halt more quickly research with hazardous or ineffective interventions. Summary of review. This review summarises the clinical research process and illustrates how and when systematic reviews may be used throughout the development programme. Meta-analyses should be performed after observational studies, preclinical studies in experimental stroke, and after phase I, II, and III clinical trials and phase IV clinical surveillance studies. Although meta-analyses most commonly work with summary data, they may be performed to assess relationships between variables (meta-regression) and, ideally, should utilise individual patient data. Meta-analysis techniques may alsoworkwith ordered categorical outcome data (ordinal meta-analysis) and be used to perform indirect comparisons where original trial data do not exist. Conclusion Systematic review/meta-analyses are powerful tools in medical research and should be used throughout the development of all stroke and other interventions

Chromium supplementation in patients with type 2 diabetes and high risk of type 2 diabetes: a meta-analysis of randomized controlled trials

Introduction: Chromium is an essential trace mineral for carbohydrate and lipid metabolism, which is currently prescribed to control diabetes mellitus. Results of previous systematic reviews and meta-analyses of chromium supplementation and metabolic profiles in diabetes have been inconsistent. Aim: The objective of this meta-analysis was to assess the effects on metabolic profiles and safety of chromium supplementation in type 2 diabetes mellitus and cholesterol. Methods: Literature searches in PubMed, Scopus and Web of Science were made by use of related terms-keywords and randomized clinical trials during the period of 2000-2014. Results: Thirteen trials fulfilled the inclusion criteria and were included in this systematic review. Total doses of Cr supplementation and brewer's yeast ranged from 42 to 1,000 µg/day, and duration of supplementation ranged from 30 to 120 days. The analysis indicated that there was a significant effect of chromium supplementation in diabetics on fasting plasma glucose with a weighted average effect size of -29.26 mg/dL, p = 0.01, CI 95% = -52.4 to -6.09; and on total cholesterol with a weighted average effect size of -6.7 mg/dL, p = 0.01, CI 95% = -11.88 to -1.53. Conclusions: The available evidence suggests favourable effects of chromium supplementation on glycaemic control in patients with diabetes. Chromium supplementation may additionally improve total cholesterol levels.

Family-based interventions for reducing sedentary time in youth: a systematic review of randomized controlled trials

Family involvement in interventions to reduce sedentary time may help foster appropriate long-term screen-based habits in children. This review systematically synthesized evidence from randomized controlled trials of interventions with a family component that targeted reduction of sedentary time, including TV viewing, video games and computer use, in children. MEDLINE, PubMed, PsycInfo, CINAHL and Embase were searched from inception through March 2012. Seventeen articles were considered eligible and included in the review. Studies were judged to be at low-to-moderate risk of bias. Despite inconsistent study results, level of parental involvement, rather than the setting itself, appeared an important determinant of intervention success. Studies including a parental component of medium-to-high intensity were consistently associated with statistically significant changes in sedentary behaviours. Participant age was also identified as a determinant of intervention outcomes; all three studies conducted in pre-school children demonstrated significant decreases in sedentary time. Finally, TV exposure appeared to be related to changes in energy intake rather than physical activity. Future studies should assess the effects of greater parental involvement and child age on success of sedentary behaviour interventions. More research is required to better understand the relationship between screen time and health behaviours, particularly energy intake.

Assessing randomised clinical trials of cognitive and exposure therapies for gambling disorders : a systematic review

Aims: Problem or pathological gambling is associated with significant disruption to the individual, family and community with a range of adverse outcomes, including legal, financial and mental health impairment. It occurs more frequently in younger populations, and comorbid conditions are common. Cognitive–behaviour therapy (CBT) is the most empirically established class of treatments for problematic gambling. This article reports on a systematic review and evaluation of randomised clinical trials (RCTs) concerning two core techniques of CBT: cognitive and behavioural (exposure-based) therapies. Methods: PsycINFO, MEDLINE and the Cochrane library were searched from database inception to December 2012. The CONsolidated Standards Of Reporting Trials (CONSORT) for non-pharmacological treatments was used to evaluate each study. Results: The initial search identified 104 references. After two screening phases, seven RCTs evaluating either cognitive (n = 3), exposure (n = 3) or both (n = 1) interventions remained. The studies were published between 1983 and 2003 and conducted across Australia, Canada, and Spain. On average, approximately 31% of CONSORT items were rated as ‘absent’ for each study and more than 52% rated as ‘present with some limitations’. For all studies, 70.83% of items rated as ‘absent’ were in the methods section. Conclusions: The findings from this review of randomised clinical trials involving cognitive and exposure-based treatments for gambling disorders show that the current evidence base is limited. Trials with low risk of bias are needed to be reported before recommendations are given on their effectiveness and clinicians can appraise their potential utility with confidence.

Does sleep education change sleep parameters? Comparing sleep education trials for middle school students in Australia and New Zealand

Background: Adolescents suffer daytime consequences from sleep loss. Sleep education programs have been developed in an attempt to increase sleep knowledge and/or duration. This paper presents data from three trials of the Aus-tralian Centre for Education in Sleep (ACES) program for adolescents.

Methods: The ACES program was delivered to 69 Australian adolescents in a pre-post cross-sectional design (mean age 15.2) and 29 New Zealand adolescents in a randomised control trial (mean age 14.8 years). Assessments in sleep parame-ters were undertaken at baseline and post intervention.

Results: Where sleep knowledge was evaluated (Australian trials), significant improvements were shown in all trials (All p <0.05). Where sleep duration was assessed (New Zealand trial) significant improvements were found in week and weekend sleep duration [F(1, 27)=4.26, p=0.04). Both, students and teachers found the program feasible, interesting, and educational.

Conclusions: ACES sleep education programmes can improve both sleep knowledge and sleep duration in adolescents. Improving the programme so sleep knowledge attained equates to actual sleep behaviour change are areas for future direc-tion. Collectively these findings provide encouraging signs that adolescents can improve their sleep knowledge and behav-iour with sleep education which bodes well for sleep-related health and psycho-social issues.

Statins for the treatment of depression: a meta-analysis of randomized, double-blind, placebo-controlled trials

BACKGROUND: In epidemiological studies, statins appear to benefit mood, and there are now some randomized controlled trials examining the efficacy of statins. However, the role of statins in depression remains uncertain. Thus the aim of this paper was to assess the effect of statins on depressive symptoms by performing a meta-analysis of all double-blind, randomized, placebo controlled clinical trials (RCT) conducted in subjects with depression. METHODS: A systematic search was executed using PubMed and ClinicalTrials.gov in November 30th, 2015 for all double-blind, RCT of statins versus placebo in persons with depressive symptoms. Sixty-seven potential articles were identified through search of electronic databases, of those three met inclusion criteria and were included in the meta-analysis. The outcome measure was change in Hamilton Depression Rating Scale (HDRS) scores associated with statin use. A meta-analysis was conducted and standardized mean differences (SMDs) with 95% confidence intervals (CIs) were calculated. GRADE was used to assess study quality. RESULTS: The three articles included provided data on 165 participants with moderate to severe depression. Of these, 82 were randomized to statins as an adjuvant therapy to antidepressant treatment (i.e., citalopram or fluoxetine) and 83 to the placebo arm. All studies were double-blind RCTs, with a follow-up of 6-12 weeks. The statin agents evaluated were lovastatin, atorvastatin, and simvastatin. When compared to placebo, statins, as add-on to treatment as usual, largely improved depressive symptoms as assessed by the HDRS (SMD=-0.73, 95% IC -1.04 to -0.42, p<0.001, 3 between-group comparisons, n=165). No serious adverse effects were reported. CONCLUSIONS: Our results suggest that adjunctive treatment with statins could be useful for the treatment of depressive symptoms. Additional double-blind, randomised, placebo-controlled trials are necessary to settle the matter.

The science of the COAG coordinated care trials

Objectives: To explicate the organisational change agenda of the COAG coordinated care trials within the Australian health system and to illuminate the role of science in this process. Methods and Results: This article briefly outlines the COAG coordinated care trial aims and the effect of the trial as a change initiative in rural South Australia. It is proposed that although the formal trial outcomes are still not clear, the trial had significant impact upon health service delivery in some sites. The trial involved standard research methods with control and intervention groups and with key hypotheses being tested to compare the costs and service utilization profile of intervention and control groups. Formal results indicate that costs were not significantly different between intervention and control groups across all sites, but that the trial, nonetheless, had a powerful impact on the attitude and behaviours of service providers in the rural trial on Eyre Peninsula in particular. Some of the key structural changes now in place are outlined. Conclusions: The COAG trial has had many and varied impacts upon those organisations and individual providers involved with it. It is argued here that since successive initiatives had been implemented before final evaluation results were published, other agendas were served by the trial apart from those of standard scientific research and hypothesis testing. That is, the main impact of the coordinated care trial in Eyre Region at least has been change by stealth, and not through scientific research and demonstration. Implications: The COAG trials have set in train a series of structural and procedural changes in the methods of delivery and management of primary health care systems; changes that are embodied in the Enhanced Primary Care packages (EPC) and other initiatives recently introduced by the Commonwealth Government. These changes have occurred and are occurring across the system without formal evidence as to their efficacy, suggesting that other financial motives are driving these new approaches apart from the goal of improving health outcomes for consumers. Also, if science is to be used in this way to drive policy and procedural change ahead of actual outcome evidence, it is important that we examine the more subtle agendas of such research projects in future if the integrity of the scientific method is to be maintained. The occurrence of such phenomena questions the very foundation of scientific endeavour and weakens the application of scientific principles in the arena of social and political science.

Efficacy and safety of thrombin-receptor antagonist (atopaxar and vorapaxar) in patients with acute coronary syndrome or coronary artery disease-a meta-analysis of randomized controlled trials

Background: Meta-analysis for the efficacy and safety data of thrombin-receptor antagonist (TRA) based on patients with acute coronary syndrome (ACS) or coronary artery disease (CAD) and indirect comparisons between TRAs were not available. Objectives: We intended to synthesize the primary end points based on different patient populations (ACS or CAD) as well as perform indirect comparison between two newly invented antiplatelet agents atopaxar and vorapaxar. Methods: A literature search was performed in MEDLINE, Embase, and Cochrane Library. Incidences of major adverse cardiovascular events (MACEs) and bleeding events according to thrombolysis in myocardial infarction were selected as primary outcomes, whereas adverse effects were considered as secondary outcomes. Corresponding results were synthesized using Revman 5.1 according to ACS or CAD cohorts. Results: Among the seven included randomized controlled trials, the efficacy end points in the TRA treatment group were favorable compared with placebo. Specifically, the odds ratio (OR) of MACEs was 0.80 (95% confidence interval [CI] 0.52-1.22) for patients with ACS and 0.74 (95% CI 0.53-1.05) for the cohort with CAD. The events of bleeding were unanimously superior in the placebo arm for both cohorts. The indirect comparison showed a superior trend in favor of atopaxar over vorapaxar in occurrences of MACEs (OR 0.93; 95% CI 0.38-1.32), myocardial infarction (OR 0.52; 95% CI 0.13-0.95), and cardiovascular death (OR 0.82; 95% CI 0.12-4.24) and caused less incidence of bleeding. Conclusions: Besides being more effective than placebo in improving the incidence of MACEs but with a higher risk of bleeding, TRAs may exert different effects in patients with ACS and CAD. Indirect comparisons also suggested that atopaxar might be better than vorapaxar in lowering the incidence of MACEs, myocardial infarction, and cardiovascular death and at the same time with lower risks of bleeding.

Treatment trials for neonatal seizures: the effect of design on sample size

Neonatal seizures are common in the neonatal intensive care unit. Clinicians treat these seizures with several anti-epileptic drugs (AEDs) to reduce seizures in a neonate. Current AEDs exhibit sub-optimal efficacy and several randomized control trials (RCT) of novel AEDs are planned. The aim of this study was to measure the influence of trial design on the required sample size of a RCT. We used seizure time courses from 41 term neonates with hypoxic ischaemic encephalopathy to build seizure treatment trial simulations. We used five outcome measures, three AED protocols, eight treatment delays from seizure onset (Td) and four levels of trial AED efficacy to simulate different RCTs. We performed power calculations for each RCT design and analysed the resultant sample size. We also assessed the rate of false positives, or placebo effect, in typical uncontrolled studies. We found that the false positive rate ranged from 5 to 85% of patients depending on RCT design. For controlled trials, the choice of outcome measure had the largest effect on sample size with median differences of 30.7 fold (IQR: 13.7–40.0) across a range of AED protocols, Td and trial AED efficacy (p<0.001). RCTs that compared the trial AED with positive controls required sample sizes with a median fold increase of 3.2 (IQR: 1.9–11.9; p<0.001). Delays in AED administration from seizure onset also increased the required sample size 2.1 fold (IQR: 1.7–2.9; p<0.001). Subgroup analysis showed that RCTs in neonates treated with hypothermia required a median fold increase in sample size of 2.6 (IQR: 2.4–3.0) compared to trials in normothermic neonates (p<0.001). These results show that RCT design has a profound influence on the required sample size. Trials that use a control group, appropriate outcome measure, and control for differences in Td between groups in analysis will be valid and minimise sample size.

Adherence to a Mediterranean-style diet and effects on cognition in adults: a qualitative evaluation and systematic review of longitudinal and prospective trials

The Mediterranean-style diet (MedDiet) involves substantial intake of fruits, vegetables, and fish, and a lower consumption of dairy, red meat, and sugars. Over the past 15 years, much empirical evidence supports the suggestion that a MedDiet may be beneficial with respect to reducing the incidence of cardiovascular disease, cancer, metabolic syndrome, and dementia. A number of cross-sectional studies that have examined the impact of MedDiet on cognition have yielded largely positive results. The objective of this review is to evaluate longitudinal and prospective trials to gain an understanding of how a MedDiet may impact cognitive processes over time. The included studies were aimed at improving cognition or minimizing of cognitive decline. Studies reviewed included assessments of dietary status using either a food frequency questionnaire or a food diary assessment. Eighteen articles meeting our inclusion criteria were subjected to systematic review. These revealed that higher adherence to a MedDiet is associated with slower rates of cognitive decline, reduced conversion to Alzheimer's disease, and improvements in cognitive function. The specific cognitive domains that were found to benefit with improved Mediterranean Diet Score were memory (delayed recognition, long-term, and working memory), executive function, and visual constructs. The current review has also considered a number of methodological issues in making recommendations for future research. The utilization of a dietary pattern, such as the MedDiet, will be essential as part of the armamentarium to maintain quality of life and reduce the potential social and economic burden of dementia.

mHealth technologies to influence physical activity and sedentary behaviors: behavior change techniques, systematic review and meta-analysis of randomized controlled trials

BACKGROUND: mHealth programs offer potential for practical and cost-effective delivery of interventions capable of reaching many individuals.

PURPOSE: To (1) compare the effectiveness of mHealth interventions to promote physical activity (PA) and reduce sedentary behavior (SB) in free-living young people and adults with a comparator exposed to usual care/minimal intervention; (2) determine whether, and to what extent, such interventions affect PA and SB levels and (3) use the taxonomy of behavior change techniques (BCTs) to describe intervention characteristics.

METHODS: A systematic review and meta-analysis following PRISMA guidelines was undertaken to identify randomized controlled trials (RCTs) comparing mHealth interventions with usual or minimal care among individuals free from conditions that could limit PA. Total PA, moderate-to-vigorous intensity physical activity (MVPA), walking and SB outcomes were extracted. Intervention content was independently coded following the 93-item taxonomy of BCTs.

RESULTS: Twenty-one RCTs (1701 participants-700 with objectively measured PA) met eligibility criteria. SB decreased more following mHealth interventions than after usual care (standardised mean difference (SMD) -0.26, 95 % confidence interval (CI) -0.53 to -0.00). Summary effects across studies were small to moderate and non-significant for total PA (SMD 0.14, 95 % CI -0.12 to 0.41); MVPA (SMD 0.37, 95 % CI -0.03 to 0.77); and walking (SMD 0.14, 95 % CI -0.01 to 0.29). BCTs were employed more frequently in intervention (mean = 6.9, range 2 to 12) than in comparator conditions (mean = 3.1, range 0 to 10). Of all BCTs, only 31 were employed in intervention conditions.

CONCLUSIONS: Current mHealth interventions have small effects on PA/SB. Technological advancements will enable more comprehensive, interactive and responsive intervention delivery. Future mHealth PA studies should ensure that all the active ingredients of the intervention are reported in sufficient detail.

Interventions to reduce sedentary behaviour in 0-5-year-olds: A systematic review and meta-analysis of randomised controlled trials

Aim or objective To evaluate the effectiveness of behavioural interventions that report sedentary behaviour outcomes during early childhood. Design Systematic review and meta-analysis. Data sources Academic Search Complete, CINAHL Complete, Global Health, MEDLINE Complete, PsycINFO, SPORTDiscus with Full Text and EMBASE electronic databases were searched in March 2016. Eligibility criteria for selecting studies Inclusion criteria were: (1) published in a peer-reviewed English language journal; (2) sedentary behaviour outcomes reported; (3) randomised controlled trial (RCT) study design; and (4) participants were children with a mean age of =5.9 years and not yet attending primary/ elementary school at postintervention. Results 31 studies were included in the systematic review and 17 studies in the meta-analysis. The overall mean difference in screen time outcomes between groups was -17.12 (95% CI -28.82 to -5.42) min/day with a significant overall intervention effect (Z=2.87, p=0.004). The overall mean difference in sedentary time between groups was -18.91 (95% CI -33.31 to -4.51) min/day with a significant overall intervention effect (Z=2.57, p=0.01). Subgroup analyses suggest that for screen time, interventions of =6 months duration and those conducted in a community-based setting are most effective. For sedentary time, interventions targeting physical activity (and reporting changes in sedentary time) are more effective than those directly targeting sedentary time. Summary/conclusions Despite heterogeneity in study methods and results, overall interventions to reduce sedentary behaviour in early childhood show significant reductions, suggesting that this may be an opportune time to intervene.