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Concept: Meta-analysis


 To determine whether feeding infants with hydrolysed formula reduces their risk of allergic or autoimmune disease.

Concepts: Systematic review, Autoimmune disease, Meta-analysis


This review summarises the literature on shift work and its relation to insufficient sleep, chronic diseases, and accidents. It is based on 38 meta-analyses and 24 systematic reviews, with additional narrative reviews and articles used for outlining possible mechanisms by which shift work may cause accidents and adverse health. Evidence shows that the effect of shift work on sleep mainly concerns acute sleep loss in connection with night shifts and early morning shifts. A link also exists between shift work and accidents, type 2 diabetes (relative risk range 1.09-1.40), weight gain, coronary heart disease (relative risk 1.23), stroke (relative risk 1.05), and cancer (relative risk range 1.01-1.32), although the original studies showed mixed results. The relations of shift work to cardiometabolic diseases and accidents mimic those with insufficient sleep. Laboratory studies indicate that cardiometabolic stress and cognitive impairments are increased by shift work, as well as by sleep loss. Given that the health and safety consequences of shift work and insufficient sleep are very similar, they are likely to share common mechanisms. However, additional research is needed to determine whether insufficient sleep is a causal pathway for the adverse health effects associated with shift work.

Concepts: Medicine, Epidemiology, Hypertension, Heart, Chronic, Meta-analysis, Acute, Shift work


A systematic review to examine the efficacy of computer-based cognitive interventions for cognitively healthy older adults was conducted. Studies were included if they met the following criteria: average sample age of at least 55 years at time of training; participants did not have Alzheimer’s disease or mild cognitive impairment; and the study measured cognitive outcomes as a result of training. Theoretical articles, review articles, and book chapters that did not include original data were excluded. We identified 151 studies published between 1984 and 2011, of which 38 met inclusion criteria and were further classified into three groups by the type of computerized program used: classic cognitive training tasks, neuropsychological software, and video games. Reported pre-post training effect sizes for intervention groups ranged from 0.06 to 6.32 for classic cognitive training interventions, 0.19 to 7.14 for neuropsychological software interventions, and 0.09 to 1.70 for video game interventions. Most studies reported older adults did not need to be technologically savvy in order to successfully complete or benefit from training. Overall, findings are comparable or better than those from reviews of more traditional, paper-and-pencil cognitive training approaches suggesting that computerized training is an effective, less labor intensive alternative.

Concepts: Alzheimer's disease, Effectiveness, Cognitive psychology, Cognitive neuroscience, Efficacy, Meta-analysis, Video game, Mild cognitive impairment


Reproducibility is a defining feature of science, but the extent to which it characterizes current research is unknown. We conducted replications of 100 experimental and correlational studies published in three psychology journals using high-powered designs and original materials when available. Replication effects were half the magnitude of original effects, representing a substantial decline. Ninety-seven percent of original studies had statistically significant results. Thirty-six percent of replications had statistically significant results; 47% of original effect sizes were in the 95% confidence interval of the replication effect size; 39% of effects were subjectively rated to have replicated the original result; and if no bias in original results is assumed, combining original and replication results left 68% with statistically significant effects. Correlational tests suggest that replication success was better predicted by the strength of original evidence than by characteristics of the original and replication teams.

Concepts: Scientific method, Psychology, Statistics, Statistical significance, Statistical hypothesis testing, Effect size, Meta-analysis, Statistical power


BACKGROUND: To evaluate the effect of lifestyle modifications on metabolic syndrome (MetS) as assessed by its resolution and improved values for its components. METHODS: This was a systematic review and meta-analysis. Searches were performed of MEDLINE and the Cochrane Database from January 1966 to October 2011 to identify randomized controlled trials (RCTs) related to the study objective. The included studies were RCTs restricted to the English language, with a follow-up period of 6 months or more, which reported overall resolution of MetS or values of MetS components (fasting blood glucose, waist circumference, high-density lipoprotein (HDL), triglycerides, and systolic and diastolic blood pressure (SBP, DBP)) . Two investigators independently assessed study eligibility. The effect sizes were the relative proportion of patients with resolved MetS and mean differences in MetS component values from baseline to 1-year follow-up in a lifestyle-modification intervention (LMI) group versus a control (conventional lifestyle education or no treatment) group. Meta-analyses were conducted using a random-effects model. RESULTS: Eleven interventions in eight RCTs were used for the meta-analyses. The relative proportion of patients with resolved MetS in the intervention group was approximately 2.0 (95% CI 1.5 to 2.7) times greater in the intervention group compared with the control group (7 interventions, n = 2.839). LMI (5 interventions, n = 748) significantly reduced mean values for SBP by 6.4 mmHg (95% CI 9.7 to 3.2), DBP by 3.3 mmHg (95% CI 5.2 to 1.4), triglycerides by 12.0 mg/dl ( 95% CI 22.2 to 1.7), waist circumference by 2.7 cm (95% CI 4.6 to 0.9), and fasting blood glucose by 11.5 mg/dl (95% CI 22.4 to 0.6) (5 interventions), but reductions were not significant for HDL (1.3 mg/dl; 95% CI 0.6 to 3.1). CONCLUSIONS: The LMI was effective in resolving MetS and reducing the severity of related abnormalities (fasting blood glucose, waist circumference, SBP and DBP, and triglycerides) in subjects with MetS.

Concepts: Atherosclerosis, Evidence-based medicine, Systematic review, Randomized controlled trial, Blood pressure, Blood sugar, Effect size, Meta-analysis


To summarise the evidence about the efficacy of a Mediterranean diet on the management of type 2 diabetes and prediabetic states.

Concepts: Nutrition, Insulin, Diabetes mellitus type 2, Obesity, Systematic review, Randomized controlled trial, Diabetes, Meta-analysis


BACKGROUND: The aim of this review was to systematically review and meta-analyze the effects of yoga on symptoms of schizophrenia, quality of life, function, and hospitalization in patients with schizophrenia. METHODS: MEDLINE/Pubmed, Scopus, the Cochrane Library, PsycInfo, and IndMED were screened through August 2012. Randomized controlled trials (RCTs) comparing yoga to usual care or non-pharmacological interventions were analyzed when they assessed symptoms or quality of life in patients with schizophrenia. Cognitive function, social function, hospitalization, and safety were defined as secondary outcomes. Risk of bias was assessed using the risk of bias tool recommended by the Cochrane Back Review Group. Standardized mean differences (SMD) and 95% confidence intervals (CI) were calculated. RESULTS: Five RCTs with a total of 337 patients were included; 2 RCTs had low risk of bias. Two RCTs compared yoga to usual care; 1 RCT compared yoga to exercise; and 2 3-arm RCTs compared yoga to usual care and exercise. No evidence was found for short-term effects of yoga compared to usual care on positive symptoms (SMD = -0.58; 95% CI -1.52 to 0.37; P = 0.23), or negative symptoms (SMD = -0.59; 95% CI -1.87 to 0.69; P = 0.36). Moderate evidence was found for short-term effects on quality of life compared to usual care (SMD = 2.28; 95% CI 0.42 to 4.14; P = 0.02). These effects were only present in studies with high risk of bias. No evidence was found for short-term effects on social function (SMD = 1.20; 95% CI -0.78 to 3.18; P = 0.23). Comparing yoga to exercise, no evidence was found for short-term effects on positive symptoms (SMD = -0.35; 95% CI -0.75 to 0.05; P = 0.09), negative symptoms (SMD = -0.28; 95% CI -1.42 to 0.86; P = 0.63), quality of life (SMD = 0.17; 95% CI -0.27 to 0.61; P = 0.45), or social function (SMD = 0.20; 95% CI -0.27 to 0.67; P = 0.41). Only 1 RCT reported adverse events. CONCLUSIONS: This systematic review found only moderate evidence for short-term effects of yoga on quality of life. As these effects were not clearly distinguishable from bias and safety of the intervention was unclear, no recommendation can be made regarding yoga as a routine intervention for schizophrenia patients.

Concepts: Evidence-based medicine, Cochrane Collaboration, Systematic review, Cochrane Library, Randomized controlled trial, MEDLINE, Meta-analysis, Centre for Reviews and Dissemination


Pharmacists play a role in providing medication reconciliation. However, data on effectiveness on patients' clinical outcomes appear inconclusive. Thus, the aim of this study was to systematically investigate the effect of pharmacist-led medication reconciliation programmes on clinical outcomes at hospital transitions.

Concepts: Medicine, Clinical trial, Medical statistics, Effect, Effectiveness, Meta-analysis, Pharmacy


OBJECTIVE: Walking groups are increasingly being set up but little is known about their efficacy in promoting physical activity. The present study aims to assess the efficacy of interventions to promote walking in groups to promoting physical activity within adults, and to explore potential moderators of this efficacy. METHOD: Systematic literature review searches were conducted using multiple databases. A random effect model was used for the meta-analysis, with sensitivity analysis. RESULTS: The effect of the interventions (19 studies, 4 572 participants) on physical activity was of medium size (d = 0.52), statistically significant (95%CI 0.32 to 0.71, p < 0.0001), and with large fail-safe of N = 753. Moderator analyses showed that lower quality studies had larger effect sizes than higher quality studies, studies reporting outcomes over six months had larger effect sizes than studies reporting outcomes up to six months, studies that targeted both genders had higher effect sizes than studies that targeted only women, studies that targeted older adults had larger effect sizes than studies that targeted younger adults. No significant differences were found between studies delivered by professionals and those delivered by lay people. CONCLUSION: Interventions to promote walking in groups are efficacious at increasing physical activity. Despite low homogeneity of results, and limitations (e.g. small number of studies using objective measures of physical activity, publication bias), which might have influence the findings, the large fail-safe N suggests these findings are robust. Possible explanations for heterogeneity between studies are discussed, and the need for more investigation of this is highlighted.

Concepts: Systematic review, Statistical significance, Effectiveness, Efficacy, Effect size, Meta-analysis, Statistical power, Gene V. Glass


BACKGROUND: Systematic reviews have been challenged to consider effects on disadvantaged groups. A priori specification of subgroup analyses is recommended to increase the credibility of these analyses. This study aimed to develop and assess inter-rater agreement for an algorithm for systematic review authors to predict whether differences in effect measures are likely for disadvantaged populations relative to advantaged populations (only relative effect measures were addressed). METHODS: A health equity plausibility algorithm was developed using clinimetric methods with three items based on literature review, key informant interviews and methodology studies. The three items dealt with the plausibility of differences in relative effects across sex or socioeconomic status (SES) due to: 1) patient characteristics; 2) intervention delivery (i.e., implementation); and 3) comparators. Thirty-five respondents (consisting of clinicians, methodologists and research users) assessed the likelihood of differences across sex and SES for ten systematic reviews with these questions. We assessed inter-rater reliability using Fleiss multi-rater kappa. RESULTS: The proportion agreement was 66% for patient characteristics (95% confidence interval: 61%-71%), 67% for intervention delivery (95% confidence interval: 62% to 72%) and 55% for the comparator (95% confidence interval: 50% to 60%). Inter-rater kappa, assessed with Fleiss kappa, ranged from 0 to 0.199, representing very low agreement beyond chance. CONCLUSIONS: Users of systematic reviews rated that important differences in relative effects across sex and socioeconomic status were plausible for a range of individual and population-level interventions. However, there was very low inter-rater agreement for these assessments. There is an unmet need for discussion of plausibility of differential effects in systematic reviews. Increased consideration of external validity and applicability to different populations and settings is warranted in systematic reviews to meet this need.

Concepts: Evidence-based medicine, Assessment, Interval finite element, Meta-analysis, Cohen's kappa, Inter-rater reliability, Contract, Fleiss' kappa