Likelihood Of Publication Bias Research Articles

Tree Nut and Peanut Consumption and Risk of Cardiovascular Disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

CVD is the leading cause of death globally. Habitual consumption of tree nuts and peanuts is associated with cardioprotective benefits. Food-based dietary guidelines globally recommend nuts as a key component of a healthy diet. This systematic review and meta-analysis were conducted to examine the relationship between tree nut and peanut consumption and risk factors for CVD in randomized controlled trials (RCTs). MEDLINE, PubMed, CINAHL, and Cochrane Central databases were searched up to 26 September, 2021. All RCT studies that assessed the effects of tree nut or peanut consumption of any dose on CVD risk factors were included. Review Manager software was used to conduct a random effect meta-analysis for CVD outcomes from RCTs. Forest plots were generated for each outcome, between-study heterogeneity was estimated using the I2 test statistic and funnel plots and Egger's test for outcomes with ≥10 strata. The quality assessment used the Health Canada Quality Appraisal Tool, and the certainty of the evidence was assessed using grading of recommendations assessment, development, and evaluation (GRADE). A total of 153 articles describing 139 studies (81 parallel design and 58 cross-over design) were included in the systematic review, with 129 studies in the meta-analysis. The meta-analysis showed a significant decrease for LDL cholesterol, total cholesterol (TC), TG, TC:HDL cholesterol, LDL cholesterol:HDL cholesterol, and apoB following nut consumption. However, the quality of evidence was "low" for only 18 intervention studies. The certainty of the body of evidence for TC:HDL cholesterol, LDL cholesterol:HDL cholesterol, and apoB were "moderate" because of inconsistency, for TG were "low," and for LDL cholesterol and TC were "very low" because of inconsistency and the likelihood of publication bias. The findings of this review provide evidence of a combined effect of tree nuts and peanuts on a range of biomarkers to create an overall CVD risk reduction. PROSPERO (CRD42022309156).

The diagnostic accuracy of radiolabeled PSMA-ligand PET for tumour staging in newly diagnosed prostate cancer patients compared to histopathology: a systematic review and meta-analysis.

The current clinical recommendations posit the deployment of specific approved radiolabeled prostate-specific membrane antigen-ligand positron emission tomography (PSMA PET) for detecting metastatic prostate cancer during primary staging. Nevertheless, the precise efficacy of such ligands in localizing intraprostatic tumours (index tumour) and T-staging is not well established. Consequently, the objective of this inquiry is to ascertain the diagnostic accuracy of PSMA-PET in the tumour staging of newly diagnosed prostate cancer by means of a meta-analysis that integrates studies utilizing histological confirmation as the reference standard. In this study, we conducted a systematic literature search of the PubMed, Embase, Web of Science, and Cochrane Library databases using a predefined collection of search terms. These terms included 'PSMA PET', 'primary staging', and 'prostate cancer'. Subsequently, two independent reviewers evaluated all the studies based on predetermined inclusion criteria, extracted pertinent data, and assessed the quality of evidence. Any disparities were resolved by a third reviewer. A random effects Sidik-Jonkman model was applied to conduct a meta-analysis and estimate the diagnostic accuracy on a per-patient basis, along with 95% confidence intervals. Moreover, an appraisal regarding the likelihood of publication bias and the impact of small-study effects was performed utilizing both Egger's test and a graphical examination of the funnel plot. The present analysis comprised a total of twenty-three scientific papers encompassing 969 patients and involved their analysis by both qualitative and quantitative approaches. The results of this study demonstrated that the estimated diagnostic accuracy of PSMA PET/CT and PSMA PET/MRI, for the detection of intraprostatic tumours, regardless of the type of PSMA-ligand, was 86% (95% CI: 76-96%) and 97% (95% CI: 94-100%), respectively. Furthermore, the diagnostic accuracy for the detection of extraprostatic extension (EPE) was 73% (95% CI: 64-82%) and 77% (95% CI: 69-85%), while the diagnostic accuracy for the detection of seminal vesicle involvement (SVI) was 87% (95% CI: 80-93) and 90% (95% CI: 82-99%), respectively. The present investigation has demonstrated that PSMA PET/MRI surpasses currently recommended multiparametric magnetic resonance imaging (mpMRI) in terms of diagnostic accuracy as inferred from a notable data trajectory, whereas PSMA-PET/CT exhibited comparable diagnostic accuracy for intraprostatic tumour detection and T-staging compared to mpMRI. Nevertheless, the analysis has identified certain potential limitations, such as small-study effects and a potential for publication bias, which may impact the overall conclusions drawn from this study.

Abdominal Size Reduction Effect of Obesity Management Program Using Meta-analysis

This study synthesized the results of individual studies that verified the effect of the obesity management program on reducing abdominal size, conducted a systematic meta-analysis, and then reinterpreted the result of the analysis. Data collection included only individual studies published from January 2003 to March 2022, and through the screening process, a total of K=57 papers were used as final analysis targets. First, the effect size of the d value, which verified the mean difference between each individual study, ranged from minimum–5.7 to maximum 18.994 with two studies that showed significant effects of 8.0 or higher, and there were 2 studies that showed significant effects of 8.0 or higher and 7 studies showing small effects of 0.1 or lower. Secondly, the total effect size of abdominal circumference was 77%(0.77), and it was verified that the magnitude of intermediate effect in confidence interval is a minimum of 68%(0.68) to a maximum of 83%(0.83) in the 95% confidence interval. Thirdly, with regard to publication bias in the abdominal circumference, symmetry can be visually confirmed. As the rank correlation test yields the value of p at 0.0597, and thus p is greater than 0.05, the likelihood of publication bias appears low. As a result of the above research, it was confirmed that the obesity program was effective in reducing abdominal size.

Does latent Toxoplasma infection have a protective effect against developing multiple sclerosis? Evidence from an updated meta-analysis.

Previous epidemiologic evidence suggests a protective effect of Toxoplasma gondii infection against multiple sclerosis (MS) development; however, inconsistent findingshave been reported in this regard. Therefore, we performed an updated meta-analysis of observational studies to investigate the association of To. gondii infection with MS development. We searched all articles published in PubMed, Scopus, Embase and Web of Science databases as of 20 December 2021. A random effects meta-analysis model was used to generate the pooled OR at 95% CIs. The heterogeneity between studies was assessed using I2 and Cochran's Q statistics. Moreover, the likelihood of publication bias was determined by Egger's regression test. A total of 11 studies were eligible for meta-analysis, including 1172 MS cases and 1802 controls. Our findings indicated that 29.8% (95% CI 22.8 to 37.2%) of MS patients were seropositive for To. gondii infection, compared with 34.2% (95% CI 21.9 to 47.6%) of control subjects. The estimated pooled OR was 0.79 (95% CI 0.49 to 1.26), suggesting a non-significant negative association between To. gondii infection and MS development (p>0.05). The current study does not support the significant protective role of To. gondii infection on MS development. Our findings imply that further well-designed epidemiological and mechanistic studies are warranted to ascertain the possible association between To. gondii infection and MS and to exclude the potential confounders.

The effect of social relationships on cognitive decline in older adults: an updated systematic review and meta-analysis of longitudinal cohort studies

BackgroundA previous meta-analysis (Kuiper et al., 2016) has shown that multiple aspects of social relationships are associated with cognitive decline in older adults. Yet, results indicated possible bias in estimations of statistical effects due to the heterogeneity of study design and measurements. We have updated this meta-analysis adding all relevant publications from 2012 to 2020 and performed a cumulative meta-analysis to map the evolution of this growing field of research (+80% of studies from 2012-2020 compared to the period considered in the previous meta-analysis).MethodsScopus and Web of Science were searched for longitudinal cohort studies examining structural, functional and combined effects of social relationships. We combined Odds Ratios (OR) with 95% confidence intervals (CI) using random effects meta-analysis and assessed sources of heterogeneity and the likelihood of publication bias. The risk of bias was evaluated with the Quality of Prognosis Studies in Systematic Reviews (QUIPS) tool.ResultsThe review was prospectively registered on PROSPERO (ID: CRD42019130667). We identified 34 new articles published in 2012-2020. Poor social relationships were associated with cognitive decline with increasing precision of estimates compared to previously reviewed studies [(for structural, 17 articles, OR: 1.11; 95% CI: 1.08; 1.14) (for functional, 16 articles, OR: 1.12; 95% CI: 1.05; 1.20) (for combined, 5 articles, OR: 1.15; 95% CI: 1.06; 1.24)]. Meta-regression, risk and subgroup analyses showed that the precision of estimations improved in recent studies mostly due to increased sample sizes.ConclusionsOur cumulative meta-analysis would confirm that multiple aspects of social relationships are associated with cognitive decline. Yet, there is still evidence of publication bias and relevant information on study design is often missing, which could lead to an over-estimation of their statistical effects.

First-line treatment with immune checkpoint inhibitors (ICI) for metastatic gastric and esophagogastric junction (EGJ) adenocarcinoma in Latin America: Sociedad Latinoamericana de Gastroenterología Oncológica (SLAGO) evidence-based recommendations.

269 Background: Gastric and EGJ cancer in Latin America are associated with a high burden of disease and mortality. Treatment with combination chemotherapy (CT) is the current standard of care for metastatic disease, but with poor benefit. ICI appears as a new option in this setting improving survival and no local guidelines have been found addressing this issue. Methods: We carried out a comprehensive systematic review up to August 2021 and meta-analysis according to PRISMA guidelines and used the GRADE approach to summarize each question in evidence tables. Judgments regarding risk of bias, precision, consistency, directness, and likelihood of publication bias were made and categorized into 4 levels of evidence’s certainty ranging from very low to high. SLAGO formed a guideline panel composed of medical professionals from 6 countries in Latin America and prioritized 2 relevant questions. We provided de novo recommendations for the local setting using the Evidence-to-Decision (EtD) frameworks provided by GRADE to discuss benefits and harms, values and preferences, use of resources, feasibility, acceptability, and equity. Results: The panel agreed on 3 recommendations. For question 1, regarding the use of CT+ICI vs CT, the global certainty of evidence was rated as high. For question 2 (CT vs ICI), the global certainty of evidence was rated as low due to imprecision. The recommendation for question 1 was conditional for the use of CT+ICI among the population with CPS > 1 and strong among those with CPS > 5. For question 2, the recommendation was conditional against the treatment with ICI, regardless of CPS score. Concerns about the lack of economic evidence addressing the treatment's cost-effectiveness were identified. The panel highlighted the complexity of the Latin America health systems for the implementation of CT+ICI and its equity impact. Finally, some research priorities were highlighted (effectiveness in HER2+, CPS 1-4, or MSI-H tumours). Conclusions: The panel agreed on the net clinical benefit of CT+ICI for selected patients (CPS > 5). Nonetheless, cost-effectiveness data are still lacking, especially in Latin America.

Safety of using hormone replacement therapy in breast cancer survivors: A systematic review and metanalysis.

12067 Background: Improvements in breast cancer (BC) care have led to increased survival of patients; hence, more attention to long-term treatment-related adverse events and quality of life (QoL) is required. Symptoms of spontaneous and treatment-induced menopause significantly affect the QoL and adherence to endocrine therapy among BC survivors, with potential negative implications on outcome. Use of systemic hormone replacement therapy (HRT) to mitigate menopause-associated symptoms is not recommended to reduce the burden of these side effects being historically associated with an increased risk of disease recurrence. This systematic review and metanalysis aimed to estimate the effect of HRT on risk of disease recurrence in BC survivors. Methods: A systematic search of Pubmed and Embase libraries up to January 15, 2021, was conducted in order to identify randomized controlled trials (RCTs) investigating the risk of disease recurrence with the use of HRT in BC survivors. We used the random-effect model to calculate the overall risk of recurrence, reported as pooled hazard ratio (HR) with 95% confidence intervals (CI). Moreover, we performed a subgroup analysis to estimate the risk of recurrence according to hormone receptor status. The Higgins I2 index was computed to assess the heterogeneity between studies. The likelihood of publication bias was assessed by Egger’s test. Results: Four RCTs were found and three were included in the metanalysis (n = 3.973 patients); one study (n = 100 patients) was excluded due to the impossibility to extract the HR for disease recurrence. Overall, 1.990 patients were randomized to receive HRT (estrogen-progesteron combination or tibolone), while 1.983 patients were included in control groups (placebo or no HRT). As compared to control group, HRT significantly increased the risk of BC recurrence (HR 1.49, 95% CI 1.15-1.93, p = 0.002). The heterogeneity between the studies was low (39%, p = 0.194), and no publication bias was found ( p = 0.537). Two studies reported the HR according to hormone receptor status. At the subgroups analysis, the risk of BC recurrence with the use of HRT was significantly increased in hormone receptor-positive patients (HR 1.8, 95% CI 1.15-2.82, p = 0.010) but not in those with hormone receptor-negative tumors (HR 1.25, 95% CI 0.83-1.88, p = 0.290). Conclusions: Use of HRT significantly increases the risk of recurrence in BC survivors, particularly in those with hormone receptor-positive disease. Therefore, this approach remains contraindicated in this setting. Alternative interventions to mitigate menopause-related symptoms should be proposed to these patients.

Risk factors for stomach cancer: a systematic review and meta-analysis

OBJECTIVESThis report provides information on 14 behavioral and nutritional factors that can be addressed in stomach cancer prevention programs.METHODSPubMed, Web of Science, and Scopus were searched through December 2018. Reference lists were also screened. Observational studies addressing the associations between stomach cancer and behavioral factors were analyzed. Between-study heterogeneity was investigated using the χ2, τ2, and I2 statistics. The likelihood of publication bias was explored using the Begg and Egger tests and trim-and-fill analysis. Effect sizes were expressed as odds ratios (ORs) with 95% confidence intervals (CIs) using a random-effects model.RESULTSOf 52,916 identified studies, 232 (including 33,831,063 participants) were eligible. The OR (95% CI) of factors associated with stomach cancer were as follows: Helicobacter pylori infection, 2.56 (95% CI, 2.18 to 3.00); current smoking, 1.61 (95% CI, 1.49 to 1.75); former smoking 1.43 (95% CI, 1.29 to 1.59); current drinking, 1.19 (95% CI, 1.10 to 1.29); former drinking, 1.73 (95% CI, 1.17 to 2.56); overweight/obesity, 0.89 (95% CI, 0.74 to 1.08); sufficient physical activity, 0.83 (95% CI, 0.68 to 1.02); consumption of fruits ≥3 times/wk, 0.48 (95% CI, 0.37 to 0.63); consumption of vegetables ≥3 times/wk, 0.62 (95% CI, 0.49 to 0.79); eating pickled vegetables, 1.28 (95% CI, 1.09 to 1.51); drinking black tea, 1.00 (95% CI, 0.84 to 1.20); drinking green tea, 0.88 (95% CI, 0.80 to 0.97); drinking coffee, 0.99 (95% CI, 0.88 to 1.11); eating fish ≥1 time/wk 0.79 (95% CI, 0.61 to 1.03); eating red meat ≥4 times/wk 1.31 (95% CI, 0.87 to 1.96), and high salt intake 3.78 (95% CI, 1.74 to 5.44) and 1.34 (95% CI, 0.88 to 2.03), based on two different studies.CONCLUSIONSThis meta-analysis provided a clear picture of the behavioral and nutritional factors associated with the development of stomach cancer. These results may be utilized for ranking and prioritizing preventable risk factors to implement effective prevention programs.

Prognostic and Clinicopathological Significance of MUC Family Members in Colorectal Cancer: A Systematic Review and Meta-Analysis.

Objective To assess the association between MUC expression levels in colorectal cancer (CRC) tissues and prognosis and investigate the associations between MUC expression levels and CRC clinicopathological characteristics. Methods The PubMed, Embase, Cochrane Library, and Web of Science databases were searched from inception through September 13, 2019, to identify studies investigating the association between MUC expression levels in CRC tissues and prognosis. Pooled hazard ratios (HRs) or odds ratio (ORs) with 95% confidence intervals (CIs) were used to evaluate associations between MUC expression levels and prognosis or clinicopathological characteristics, respectively. The heterogeneity between studies was assessed by the I2 values, whereas the likelihood of publication bias was assessed by Egger's linear regression and Begg's rank correlation test. Results Among 33 included studies (n = 6032 patients), there were no associations between combined MUC phenotype expression levels and overall survival (OS) or disease-free survival (DFS)/relapse-free survival (RFS) in patients with CRC. In subgroup analyses, the upregulated MUC1 expression (HR = 1.50; 95% CI, 1.29–1.74; P < 0.00001) was associated with poor OS. However, the upregulated MUC2 expression (HR = 0.64; 95% CI, 0.52–0.79; P < 0.00001) was associated with better OS. Furthermore, a high level of MUC1 expression (HR = 1.99; 95% CI, 0.99–3.99; P = 0.05) was associated with shorter DFS/RFS. However, patients with a low level of MUC2 tumors showed better DFS/RFS than patients with a high level of MUC2 tumors (HR = 0.71; 95% CI, 0.49–1.04; P = 0.08; P = 0.0.009, I2 = 67%) and MUC5AC expression (HR = 0.56; 95% CI, 0.38–0.82; P = 0.003) was associated with longer DFS/RFS. In addition, a high level of MUC1 expression was associated with CRC in the rectum, deeper invasion, lymph node metastasis, distant metastasis, advanced tumor stage, and lymphatic invasion. A high level of MUC2 expression had a protective effect. High secretion of MUC5AC is associated with colon cancer compared with rectal cancer. Conclusion The protein expression of MUC1 might be a poor biomarker in colorectal cancer and might play a role in tumor transformation and metastasis. However, the protein expression of MUC2 expression might have a protective effect. Furthermore, randomized controlled trials (RCTs) of large patients are needed to confirm the results.

Mucin Expression in Colorectal Cancer (CRC): Systematic Review and Meta-Analysis.

A body of evidence has suggested that mucins play an important role in adhesion, invasion, and cancer metastasis. However, this evidence is scarce and sometimes confusing. We performed a systematic review and meta-analysis of available studies to better define the role of mucins in the behavior of colorectal cancer (CRC). Medical literature was searched through November 30, 2017, using suitable keywords. Pooled estimates, that is, odd ratios (ORs), were obtained using fixed or random-effects models, as appropriate. Heterogeneity between studies was evaluated with the Cochran Q test and I values, whereas the likelihood of publication bias was assessed by constructing funnel plots. Their symmetry was estimated by the Begg and Mazumdar adjusted rank correlation test and by the Egger regression test. A total of 2234 CRC patients were included in 12 studies, eligible for meta-analysis. There was a significant difference concerning total mucin expression between CRC patients and controls [pooled ORs (95% confidence interval)=8.156 (2.624-25.354), test for overall effect Z=3.627, P<0.0001]. There was no significant publication bias. This significant difference was constricting to MUC1. In addition, there was a significance concerning MUC1 overexpression according to the stage of CRC, that is advanced stage versus localized disease [ORs (95% confidence interval)=2.724 (1.211-6.127), Z= 2.423, P=0.015], as opposed to MUC2 and MUC4. MUC1 is overexpressed in CRC tissue comparing with healthy mucosa, and may have a role in the neoplastic transformation and metastatic process. MUC2 has probably no role in carcinogenesis.

Systematic review and meta-analysis of incisional hernia post-reversal of ileostomy.

Incisional hernia following closure of loop ileostomy is a common problem. Assessment of the proportion of this complication is limited by small sample size and inconsistent reporting. The aim of this review was to provide an estimate of the proportion of incisional hernia following closure of loop ileostomy according to clinical and radiological diagnostic criteria and to investigate the association of bibliometric and study quality parameters with reported proportion. A systematic review of PubMed, Embase, CENTRAL, ISRCTN Registry and Open Grey from 2000 onwards was performed according to PRISMA standards. Reporting on the type of stoma and mesh reinforcement after closure was mandatory for inclusion, whereas studies on paediatric populations were excluded. Fixed effect or random effects models were used to calculate pooled proportion estimates. Meta-regression models were formed to explore potential heterogeneity. 42 studies with 7166 patients were included. The pooled estimate of the proportion of incisional hernia after ileostomy closure was 6.1% (95% confidence interval, CI 4.4-8.3%). Proportion estimates for higher quality studies and studies reporting on incisional hernia as primary outcome were 9.0% (95% CI 6.3-12.7%) and 13.1% (95% CI 8.8-19.1%). Significant between-study heterogeneity was identified (P < 0.001, I2 = 87%) and the likelihood of publication bias was high (P = 0.028). Mixed effects regression showed that both year of publication (P = 0.034, Q = 4.484, df = 1.000) and defining hernia as a primary outcome (Q = 20.298, P < 0.001) were related to effect size. Method of follow-up and quality of the studies affected the proportion. The proportion of incisional hernia at ileostomy closure site is estimated at 6.1%. Reporting incisional hernia as primary or secondary outcome, the method of diagnosis, the year of publication and methodological quality are associated with reported proportion.

Chevron osteotomy versus scarf osteotomy for hallux valgus correction: A meta-analysis

BackgroundThis study intended to investigate the optimal surgical strategy in hallux valgus (HV), and to provide a basis for clinical treatment of HV. MethodsStudies related to chevron osteotomy and scarf osteotomy for HV were enrolled from online databases. Hallux valgus angle (HVA) was the main outcome variable. Enrolled studies included posttreatment data for intermetatarsal angle (IMA), American Orthopaedic Foot & Ankle Society (AOFAS) score, and complications. A random-effects model was applied for significant heterogeneity. Otherwise, a fixed-effects model was used. Heterogeneity was assessed with Q test and I2 statistics. Publication bias was evaluated with Egger's test. Based on the influence of weighted mean difference values or odds ratios, a sensitivity analysis was performed. ResultsFour studies including 384 subjects were evaluated to determine the optimal surgical strategy for HV. There was no statistically significant difference between chevron and scarf groups for HVA, IMA, AOFAS score, and complication rates. Sensitivity analysis showed good stability. The likelihood of publication bias was small. ConclusionThe effects of chevron osteotomy and scarf osteotomy for HV are comparable. Chevron osteotomy is less technically demanding.

A Systematic Overview of Reviews on the Efficacy of Complementary and Alternative Medicine in Erectile Dysfunction

Background & aim: This systematic overview of reviews on complementary and alternative medicine (CAM) was performed to summarize the clinical efficacy of this approach in the treatment of erectile dysfunction (ED) and assess methodological quality of the included reviews. Methods: A comprehensive search was performed to find the systematic reviews and meta-analyses on CAM interventions (e.g., acupuncture, saffron, yohimbine, and ginseng) for ED treatment, published until October 2017. To this end, we searched the international databases, including PubMed, Scopus, and Cochrane, as well as Iranian databases, such as SID, IranMedex, and Magiran. The assessment of the methodological quality of the included systematic reviews was accomplished using the AMSTAR scale. Results: The searching process led to the inclusion of five systematic reviews examining CAM therapies, including acupuncture, saffron, Yohimbine, and ginseng. The methodological quality of the retrieved reviews was at a favorable level. Positive results were found for the administration of yohimbine, saffron, and ginseng as treatment agents for ED. However, there was insufficient evidence regarding the effect of acupuncture on this health problem. Major methodological defects included the use of a grey literature search, likelihood of publication bias, and conflicts of interests. Conclusion: As the findings indicated, CAM appeared to be an effective treatment for ED. However, it is essential to conduct further studies on the safety and value of CAM for the management of this condition.

Payer Perspective of the American Academy of Sleep Medicine Clinical Practice Guideline for the Pharmacologic Treatment of Chronic Insomnia

Payer Perspective of the American Academy of Sleep Medicine Clinical Practice Guideline for the Pharmacologic Treatment of Chronic Insomnia

What Causes Unethical Behavior? A Meta‐Analysis to Set an Agenda for Public Administration Research

AbstractThis article uses meta‐analysis to synthesize 137 experiments in 73 articles on the causes of unethical behavior. Results show that exposure to in‐group members who misbehave or to others who benefit from unethical actions, greed, egocentrism, self‐justification, exposure to incremental dishonesty, loss aversion, challenging performance goals, or time pressure increase unethical behavior. In contrast, monitoring of employees, moral reminders, and individuals’ willingness to maintain a positive self‐view decrease unethical conduct. Findings on the effect of self‐control depletion on unethical behavior are mixed. Results also present subgroup analyses and several measures of study heterogeneity and likelihood of publication bias. The implications are of interest to both scholars and practitioners. The article concludes by discussing which of the factors analyzed should gain prominence in public administration research and uncovering several unexplored causes of unethical behavior.

Anabolic steroids for rehabilitation after hip fracture in older people.

Anabolic steroids for rehabilitation after hip fracture in older people.

Colon neoplasia in patients with type 2 diabetes on metformin: A meta-analysis

BackgroundA growing body of evidence has suggested that metformin potentially reduces the risk of cancer. ObjectiveWe performed a meta-analysis of available studies to better define the effect of metformin on colon neoplasia (cancer and polyps) in patients with type 2 diabetes. MethodsMedical literature searches for human studies were performed through December 2015, using suitable keywords. Pooled estimates were obtained using fixed or random-effects models. Heterogeneity between studies was evaluated with the Cochran Q test whereas the likelihood of publication bias was assessed by constructing funnel plots. Their symmetry was estimated by the Begg and Mazumdar adjusted rank correlation test and by the Egger's regression test. In addition subgroup and sensitivity analyses were performed. ResultsA total number of 709,980 patients, with type 2 diabetes, were included in 17 studies eligible for meta-analysis [1 RCT and 16 observational studies (13 cohort and 3 case–controls)]. The risk of colon neoplasia was significantly lower among metformin users than controls (non-metformin users) [pooled RRs (95% CI)=0.75 (0.65–0.87), test for overall effect Z=−3.95, p<0.001]. This observation applied separately for colon cancer [0.79 (0.69–0.91), Z=−3.34, p<0.001] and for colon polyps [0.58 (0.42–0.80), Z=−3.30, p<0.001]. ConclusionThis meta-analysis shows that the use of metformin in patients with type 2 diabetes is associated with significantly lower risk of colon neoplasia.

Social relationships and cognitive decline: a systematic review and meta-analysis of longitudinal cohort studies.

Although poor social relationships are assumed to contribute to cognitive decline, meta-analytic approaches have not been applied. Individual study results are mixed and difficult to interpret due to heterogeneity in measures of social relationships. We conducted a systematic review and meta-analysis to investigate the relation between poor social relationships and cognitive decline. MEDLINE, Embase and PsycINFO were searched for longitudinal cohort studies examining various aspects of social relationships and cognitive decline in the general population. Odds ratios (ORs) with 95% confidence intervals (CIs) were pooled using random effects meta-analysis. Sources of heterogeneity were explored and likelihood of publication bias was assessed. We stratified analyses according to three aspects of social relationships: structural, functional and a combination of these. We identified 43 articles. Poor social relationships predicted cognitive decline; for structural (19 studies): pooled OR: 1.08 (95% CI: 1.05-1.11); functional (8 studies): pooled OR: 1.15 (95% CI: 1.00-1.32); and combined measures (7 studies): pooled OR: 1.12 (95% CI: 1.01-1.24). Meta-regression and subgroup analyses showed that the heterogeneity could be explained by the type of social relationship measurement and methodological quality of included studies. Despite heterogeneity in study design and measures, our meta-analyses show that multiple aspects of social relationships are associated with cognitive decline. As evidence for publication bias was found, the association might be overestimated and should therefore be interpreted with caution. Future studies are needed to better define the mechanisms underlying these associations. Potential causality of this prognostic association should be examined in future randomized controlled studies.

The association between Helicobacter pylori infection and inflammatory bowel disease based on meta-analysis.

In humans there are epidemiological data suggesting a protective effect of Helicobacter pylori (H. pylori) infection against the development of autoimmune diseases and in addition, there are laboratory data illustrating H. pylori's ability to induce immune tolerance and limit inflammatory responses. Thus, numerous observational studies have examined the association between H. pylori infection and inflammatory bowel disease (IBD) with various results. We performed a meta-analysis of available studies to better define the association of H. pylori infection and IBD. Medical literature searches for human studies were performed through September 2014, using suitable keywords. In each study the risk ratio (RR) of H. pylori infection in IBD patients vs controls was calculated and pooled estimates were obtained using fixed- or random-effects models as appropriate. Heterogeneity between studies was evaluated using Cochran Q test and I(2) statistics, whereas the likelihood of publication bias was assessed by constructing funnel plots. Thirty-three studies were eligible for meta-analysis, including 4400 IBD patients and 4763 controls. Overall 26.5% of IBD patients were positive for H. pylori infection, compared to 44.7% of individuals in the control group. There was significant heterogeneity in the included studies (Q = 137.2, df (Q) =32, I(2) ( )= 77%, p < 0.001) and therefore the random-effects model of meta-analysis was used. The obtained pool RR estimation was 0.62 (95% confidence interval (CI) 0.55-0.71, test for overall effect Z = -7.04, p < 0.001). There was no evidence of publication bias. The results of this meta-analysis showed a significant negative association between H. pylori infection and IBD that supports a possible protective benefit of H. pylori infection against the development of IBD.

Association Between Overweight or Obesity and Lumbar Disk Diseases: A Meta-Analysis.

A meta-analysis. We performed this meta-analysis to evaluate the association between overweight and lumbar disease. An extensive English language literature retrieval regarding the association between overweight and the risk of lumbar disease was conducted on Public Medline and Excerpta Medica Database until May 2014. Meta-analysis for all the included literatures was performed by STATA 11.0 to summarize test performance with forest plots after heterogeneity test. Moreover, subgroup and sensitivity analyses were performed to examine the potential candidate effect factors. Afterward, the likelihood of publication bias was assessed by constructing funnel plots and performing Begg rank correlation test and Egger linear regression method. A total of 5 studies satisfied the predefined eligibility criteria, including 1749 cases with lumbar disk diseases and 1885 controls. Altogether, overweight was associated with increased risk of lumbar disease [odds ratio (OR)=1.45; 95% confidence interval (CI), 1.27, 1.66; P<0.001]. Moreover, subgroup analysis proved that overweight was a predominant factor in development of lumbar disease compared with age and sex. Although significant publication bias was observed in our meta-analysis, we proved high credibility of meta-analysis result using trim and fill method (OR=1.27; 95% CI, 1.06, 1.53). We suggest that overweight might increase the risk of lumbar diseases, and weight control should be considered for overweight or obese population to reduce the occurrence and development of lumbar disease.