The effect of obesity on polycystic ovary syndrome : a systematic review and meta-analysis

While many women with polycystic ovary syndrome (PCOS) are overweight, obese or centrally obese, the effect of excess weight on the outcomes of PCOS is inconsistent. The review aimed to assess the effects of overweight, obesity and central obesity on the reproductive, metabolic and psychological features of PCOS. MEDLINE, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials (CENTRAL) and PSYCINFO were searched for studies reporting outcomes according to body mass index categories or body fat distribution. Data were presented as mean difference or risk ratio (95% confidence interval). This review included 30 eligible studies. Overweight or obese women with PCOS had decreased sex hormone-binding globulin (SHBG), increased total testosterone, free androgen index, hirsutism, fasting glucose, fasting insulin, homeostatic model assessment-insulin resistance index and worsened lipid profile. Obesity significantly worsened all metabolic and reproductive outcomes measured except for hirsutism when compared to normal weight women with PCOS. Overweight women had no differences in total testosterone, hirsutism, total-cholesterol and low-density lipoprotein-cholesterol compared to normal weight women and no differences in SHBG and total testosterone compared to obese women. Central obesity was associated with higher fasting insulin levels. These results suggest that prevention and treatment of obesity is important for the management of PCOS.

Effectiveness of interventions to promote physical activity among socioeconomically disadvantaged women : a systematic review and meta-analysis

Physical activity is important for preventing weight gain and obesity, but women experiencing socioeconomic disadvantage are at high risk of inactivity. This study aimed to determine the effectiveness of interventions to increase physical activity among women experiencing disadvantage, and the intervention factors (i.e. physical activity measure, delivery mode, delivery channel, setting, duration, use of theory, behavioural techniques, participant age, risk of bias) associated with effectiveness. We conducted a meta-analysis of controlled trials using random-effects models and meta-regression. Seven databases were searched for trials among healthy women (18–64 years), which included a physical activity intervention, any control group, and statistical analyses of a physical activity outcome at baseline and post-intervention. Nineteen studies were included (n = 6,339). Because of substantial statistical heterogeneity (χ2 = 53.61, df = 18, P < 0.0001, I2 = 66%), an overall pooled effect is not reported. In subgroup analyses, between-group differences were evident for delivery mode, which modestly reduced heterogeneity (to 54%). Studies with a group delivery component had a standardized mean difference of 0.38 greater than either individual or community-based delivery. Programs with a group delivery mode significantly increase physical activity among women experiencing disadvantage, and group delivery should be considered an essential element of physical activity promotion programs targeting this population group.

The impact of statins on psychological wellbeing : a systematic review and meta-analysis

Background : Cholesterol-lowering medications such as statins have anti-inflammatory and antioxidant properties, which may be beneficial for treating depression and improving mood. However, evidence regarding their effects remains inconsistent, with some studies reporting links to mood disturbances. We aimed to conduct a meta-analysis to determine the impact of statins on psychological wellbeing of individuals with or without hypercholesterolemia.

Methods : Articles were identified using medical, health, psychiatric and social science databases, evaluated for quality, and data were synthesized and analyzed in RevMan-5 software using a random effects model.

Results : The 7 randomized controlled trials included in the analysis represented 2,105 participants. A test for overall effect demonstrated no statistically significant differences in psychological wellbeing between participants receiving statins or a placebo (standardized mean difference (SMD) = -0.08, 95% CI -0.29 to 0.12; P = 0.42). Sensitivity analyses were conducted to separately analyze depression (n = 5) and mood (n = 2) outcomes; statins were associated with statistically significant improvements in mood scores (SMD = -0.43, 95% CI -0.61 to -0.24).

Conclusions : Our findings refute evidence of negative effects of statins on psychological outcomes, providing some support for mood-related benefits. Future studies could examine the effects of statins in depressed populations.

Physical activity for cancer survivors : a meta-analysis of randomised controlled trials

Objective To systematically evaluate the effects of physical activity in adult patients after completion of main treatment related to cancer. Design Meta-analysis of randomised controlled trials with data extraction and quality assessment performed independently by two researchers. Data sources Pubmed, CINAHL, and Google Scholar from the earliest possible year to September 2011. References from meta-analyses and reviews. Study selection Randomised controlled trials that assessed the effects of physical activity in adults who had completed their main cancer treatment, except hormonal treatment. Results There were 34 randomised controlled trials, of which 22 (65%) focused on patients with breast cancer, and 48 outcomes in our meta-analysis. Twenty two studies assessed aerobic exercise, and four also included resistance or strength training. The median duration of physical activity was 13 weeks (range 3-60 weeks). Most control groups were considered sedentary or were assigned no exercise. Based on studies on patients with breast cancer, physical activity was associated with improvements in insulin-like growth factor-I, bench press, leg press, fatigue, depression, and quality of life. When we combined studies on different types of cancer, we found significant improvements in body mass index (BMI), body weight, peak oxygen consumption, peak power output, distance walked in six minutes, right handgrip strength, and quality of life. Sources of study heterogeneity included age, study quality, study size, and type and duration of physical activity. Publication bias did not alter our conclusions. Conclusions Physical activity has positive effects on physiology, body composition, physical functions, psychological outcomes, and quality of life in patients after treatment for breast cancer. When patients with cancer other than breast cancer were also included, physical activity was associated with reduced BMI and body weight, increased peak oxygen consumption and peak power output, and improved quality of life.

Economic evaluation of adult rehabilitation: a systematic review and meta-analysis of randomized controlled trials in a variety of settings

Objectives:
To report if there is a difference in costs from a societal perspective between adults receiving rehabilitation in an inpatient rehabilitation setting versus an alternative setting. If there are cost differences, to report whether opting for the least expensive program setting adversely affects patient outcomes.

Data Sources:
Electronic databases from the earliest possible date until May 2011. All languages were included.

Study Selection
Multiple reviewers identified randomized controlled trials with a full economic evaluation that compared adult inpatient rehabilitation with an alternative. There were 29 included trials with 6746 participants.

Data Extraction
Multiple observers extracted data independently. Trial appraisal included a risk of bias assessment and a checklist to report the strength of the economic evaluation.

Data Synthesis:
Results were synthesized using standardized mean differences (SMDs) and meta-analyses for the primary outcome of cost. The Grading of Recommendations Assessment, Development, and Evaluation was applied to assess for risk of bias across studies for meta-analyses. There was high-quality evidence that cost was significantly reduced for rehabilitation in the home versus inpatient rehabilitation in a meta-analysis of 732 patients poststroke (pooled SMD [δ]=−.28; 95% confidence interval [CI], −.47 to −.09), without compromise to patient outcomes. Results of individual trials in other patient groups (orthopedic, rheumatoid arthritis, and geriatric) receiving rehabilitation in the home or community were generally consistent with the meta-analysis. There was moderate quality evidence that cost was significantly reduced for inpatient rehabilitation (stroke unit) versus general acute care in a meta-analysis of 463 patients poststroke (δ=.31; 95% CI, .15–.48), with improvement to patient outcomes. These results were not replicated in 2 individual trials with a geriatric and a mixed cohort, where costs did not differ between general acute care and inpatient rehabilitation. Three of the 4 individual trials, inclusive of a stroke or orthopedic population, reported less cost for an intensive inpatient rehabilitation program compared with usual inpatient rehabilitation. Sensitivity analysis included a health service perspective and varied inflation rates with no change to the significant findings of the meta-analyses.

Conclusions:
Based on this systematic review and meta-analyses, a single rehabilitation service may not provide health economic benefits for all patient groups and situations. For some patients, inpatient rehabilitation may be the most cost-effective method of providing rehabilitation; yet, for other patients, rehabilitation in the home or community may be the most cost-effective model of care. To achieve cost-effective outcomes, the ideal combination of rehabilitation services and patient inclusion criteria, as well as further data for nonstroke populations, warrants further research.

Interventions designed to limit gestational weight gain: a systematic review of theory and meta-analysis of intervention components

Limiting gestational weight gain (GWG) to recommended levels is important to optimize health outcomes for mother and baby. Surprisingly, a recent review revealed that theory-based interventions to limit GWG were less effective than interventions that did not report a theory-base; however, strict criteria were used to identify theory-informed studies. We extended this review and others by systematically evaluating the theories of behaviour change informing GWG interventions using a generalized health psychology perspective, and meta-analysing behaviour change techniques reported in the interventions. Interventions designed to limit GWG were searched for using health, nursing and psychology databases. Papers reporting an underpinning theory were identified and the CALO-RE taxonomy was used to determine individual behaviour change techniques. Nineteen studies were identified for inclusion. Eight studies were informed by a behaviour change theory; six reported favourable effects on GWG. Overall, studies based on theory were as effective as non–theory-based studies at limiting GWG. Furthermore, the provision of information, motivational interviewing, behavioural self-monitoring and providing rewards contingent on successful behaviour appear to be key strategies when intervening in GWG. Combining these behaviour change techniques with dietary interventions may be most effective. Future research should focus on determining the exact combination of behaviour change techniques, or which underpinning theories, are most useful for limiting GWG.

Racism as a determinant of health: a protocol for conducting a systematic review and meta-analysis

Background: 

Fundamental Movement Skill Interventions in Youth: A Systematic Review and Meta-analysis

BACKGROUND
Fundamental movement skill (FMS) proficiency is positively associated with physical activity and fitness levels. The objective of this study was to systematically review evidence for the benefits of FMS interventions targeting youth.

METHODS
A search with no date restrictions was conducted across 7 databases. Studies included any school-, home-, or community-based intervention for typically developing youth with clear intent to improve FMS proficiency and that reported statistical analysis of FMS competence at both preintervention and at least 1 other postintervention time point. Study designs included randomized controlled trials (RCTs) using experimental and quasi-experimental designs and single group pre-post trials. Risk of bias was independently assessed by 2 reviewers.

RESULTS
Twenty-two articles (6 RCTs, 13 quasi-experimental trials, 3 pre-post trials) describing 19 interventions were included. All but 1 intervention were evaluated in primary/elementary schools. All studies reported significant intervention effects for ≥1 FMS. Meta-analyses revealed large effect sizes for overall gross motor proficiency (standardized mean difference [SMD] = 1.42, 95% confidence interval [CI] 0.68–2.16, Z = 3.77, P < .0002) and locomotor skill competency (SMD = 1.42, 95% CI 0.56–2.27, Z = 3.25, P = .001). A medium effect size for object control skill competency was observed (SMD = 0.63, 95% CI 0.28–0.98, Z = 3.53, P = .0004). Many studies scored poorly for risk of bias items.

CONCLUSIONS
School- and community-based programs that include developmentally appropriate FMS learning experiences delivered by physical education specialists or highly trained classroom teachers significantly improve FMS proficiency in youth.

A systematic review and meta-analysis of diabetes and risk of physical disability and functional impairment - protocol

Background
Diabetes and increased age are known risk factors for physical disability. With the increasing prevalence of diabetes within our aging population, the future burden of disability is expected to increase. To date, there has not been a pooled estimate of the risk for disability associated with diabetes or its precursor states, impaired glucose tolerance and impaired fasting glucose. We aim to conduct a systematic review and meta-analysis of the association between prediabetes and diabetes with disability, and quantify the risk of association.

Methods/design
We will search for relevant studies in Medline via Pubmed, Embase, Cochrane library and Cumulative Index to Nursing and Allied Health Literature (CINAHL), as well as scan reference lists from relevant reviews and publications included in our review. We will review all publications that include studies on human adults (18 years and older) where information is included on diabetes status and at least one measure of disability (Activities of Daily Living (ADL), Instrumental ADL (IADL) or functional/mobility limitation), and where a risk association is available for the relationship between diabetes and/or prediabetes with disability, with reference to those without diabetes.

We will further conduct a meta-analysis to pool estimates of the risk of disability associated with prediabetes and diabetes. Sensitivity analysis will be conducted to assess for publication bias and study quality.Findings from this systematic review and meta-analysis will be widely disseminated through discussions with stake-holders, publication in a peer-reviewed journal and conference presentation.

Student self-assessment in higher education: a meta-analysis

Quantitative self-assessment studies that compared self- and teacher marks were subjected to a meta-analysis. Predictions stemming from the results of an earlier critical review of the literature (Boud & Falchikov, 1989) were tested, and salient variables were identified. Factors that seem to be important with regard to the closeness of correspondence between self- and teacher marks were found to include the following: the quality of design of the study (with better designed studies having closer correspondence between student and teacher than poorly designed ones); the level of the course of which the assessment was a part (with students in advanced courses appearing to be more accurate assessors than those in introductory courses); and the broad area of study (with studies within the area of science appearing to produce more accurate self-assessment generally than did those from other areas of study). Results of the analysis are discussed and differences signaled by the results of the three common metrics examined. The distinction between relative and absolute judgment of performance is drawn. It is recommended that researchers give attention to both good design and to adequate reporting of self-assessment studies.

Multivitamin-multimineral supplementation and mortality: a meta-analysis of randomized controlled trials

BACKGROUND: Multivitamins are the most commonly used supplement in the developed world. Recent epidemiologic findings suggest that multivitamin use increases the risk of mortality. OBJECTIVE: We aimed to determine whether multivitamin-multimineral treatment, used for primary or secondary prevention, increases the risk of mortality in independently living adults. DESIGN: We performed a meta-analysis of randomized controlled trials. Multiple electronic databases were systematically searched from March to October 2012. Randomized controlled primary or secondary prevention trials were considered for inclusion. Eligible trials investigated daily multivitamin-multimineral supplementation for ≥1 y. Cohorts described as institutionalized or as having terminal illness (tertiary prevention) were excluded. The number of deaths and the sample size of each study arm were extracted independently by 2 researchers. Twenty-one articles were included in the analysis, which generated a total pooled sample of 91,074 people and 8794 deaths. These trials were pooled in a meta-analysis, and the outcomes were expressed as RRs and 95% CIs. RESULTS: The average age of the pooled sample was 62 y, and the average duration of supplementation was 43 mo. Across all studies, no effect of multivitamin-multimineral treatment on all-cause mortality (RR: 0.98; 95% CI: 0.94, 1.02) was observed. There was a trend for a reduced risk of all-cause mortality across primary prevention trials (RR: 0.94; 95% CI: 0.89, 1.00). Multivitamin-multimineral treatment had no effect on mortality due to vascular causes (RR: 1.01; 95% CI: 0.93, 1.09) or cancer (RR: 0.96; 95% CI: 0.88, 1.04). No statistical evidence of heterogeneity or publication bias was observed. CONCLUSION: Multivitamin-multimineral treatment has no effect on mortality risk.

The effects of multivitamins on cognitive performance: a systematic review and meta-analysis

Complementary medicine use is becoming increasingly popular with multivitamins being the most commonly used vitamin supplement. Although adequate vitamin and nutrient concentrations are necessary for optimal health and cognitive functioning, there is no scientific consensus as to whether multivitamin use prevents cognitive decline or improves mental functioning. The aim of the present study was to determine if multivitamins can be used efficaciously to improve cognitive abilities. A systematic review of randomized controlled trials was performed. Meta-analysis was performed on those cognitive tests used across the largest number of studies. Multiple electronic databases were searched until July 2011 by two authors. Randomized, placebo-controlled trials were considered appropriate if they reported on the chronic effects (≥1 month) of oral multivitamin supplementation on any valid cognitive outcomes. Ten trials were included in review (n = 3,200). Meta-analysis indicated that multivitamins were effective in improving immediate free recall memory (SMD = 0.32; 95% CI: 0.09-0.56, p < 0.01) but not delayed free recall memory (SMD = -0.14; 95% CI: -0.43-0.14, p = 0.33) or verbal fluency (SMD = 0.06; 95% CI: -0.05-0.18, p = 0.26). There was no evidence of publication bias or heterogeneity. Other cognitive abilities sensitive to AD pathology, such as executive and visuospatial functions, were found to be under researched. In conclusion, multivitamins were found to enhance immediate free recall memory but no other cognitive domains.

Peripheral vascular endothelial growth factor as a novel depression biomarker: a meta-analysis

BACKGROUND: The neurotrophic hypothesis of major depressive disorder (MDD) postulates that the pathology of this illness incorporates a down-regulation of neurotrophin signaling. Brain-derived neurotrophic factor (BDNF) is the most studied neurotrophic mediator regarding the neurobiology of MDD. Nevertheless, emerging evidence has implicated the multi-competent angiogenic and neurogenic molecule - vascular endothelial growth factor (VEGF) - in hippocampal neurogenesis and depression pathophysiology. OBJECTIVE: To compare peripheral levels of VEGF between individuals with MDD and healthy controls. METHODS: We performed a systematic review and meta-analysis of original studies measuring peripheral levels of VEGF in participants with MDD compared to healthy controls. We searched the Pubmed/MEDLINE, EMBASE and PsycInfo databases for studies published in any language through December 16th, 2014. RESULTS: Fourteen studies met eligibility criteria (N=1633). VEGF levels were significantly elevated in individuals with MDD when compared to healthy controls (Hedges's g=0.343; 95% CI: 0.146-0.540; P<0.01). Funnel plot inspection and the Egger's test did not provide evidence of publication bias. A significant degree of heterogeneity was observed (Q=38.355, df=13, P<0.001; I(2)=66.1%), which was explored through meta-regression and subgroup analyses. Overall methodological quality, sample for assay (plasma versus serum), as well as the matching of MDD and control samples for age and gender emerged as significant sources of heterogeneity. CONCLUSIONS: Taken together, extant data indicate that VEGF shows promise as a biomarker for MDD, and supports that this mediator may be involved in neuroplasticity mechanisms underlying the pathophysiology of MDD.

Community factors influencing child and adolescent depression: A systematic review and meta-analysis

OBJECTIVE: Depression has been identified as a priority disorder among children and adolescents. While numerous reviews have examined the individual and family factors that contribute to child and adolescent depressive symptoms, less is known about community-level risk and protective factors. The aim of this study was to complete a systematic review to identify community risk and protective factors for depression in school-aged children (4-18 years). METHOD: The review adopted the procedures recommended by the Cochrane Non-Randomised Studies Methods Working Group and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive literature search was conducted to identify both observational and intervention study designs in both peer-reviewed and non-peer reviewed publications. RESULTS: A total of 21 studies met the inclusion criteria. Seventeen of the 18 community association studies and 2 of the 3 intervention studies reported one or more significant effects. Results indicated that community safety and community minority ethnicity and discrimination act as risk factors for depressive symptoms in school-aged children. Community disadvantage failed to achieve significance in meta-analytic results but findings suggest that the role of disadvantage may be influenced by other factors. Community connectedness was also not directly associated with depressive symptoms. CONCLUSION: There is evidence that a number of potentially modifiable community-level risk and protective factors influence child and adolescent depressive symptoms suggesting the importance of continuing research and intervention efforts at the community-level.

Meta-analysis of the income and price elasticities of gasoline demand: public policy implications for Latin America

By means of a meta-analysis, this article sets out to estimate average values for the income and price elasticities of gasoline demand and to analyse the reasons for the variations in the elasticities reported by the literature. The findings show that there is publication bias, that the volatility of elasticity estimates is not due to sampling errors alone, and that there are systematic factors explaining these differences. The income and price elasticities of gasoline demand differ between the short and long run and by region, and the estimation can appropriately include the vehicle fleet and the prices of substitute goods, the data types and the estimation methods used. The presence of a low price elasticity suggests that a fuel tax will be inadequate to control rising consumption in a context of rapid economic growth.