Likelihood Of Publication Bias Research Articles

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.

A systematic evaluation on the quality of Meta-analysis in articles published in the Chinese Journal of Gastrointestinal Surgery from 1998 to 2014

To assess the methodological quality and reporting quality on Meta-analysis being published in the Chinese Journal of Gastrointestinal Surgery. Computerized literature searching was carried out in Wanfang Medical Online to collect articles that Meta-analysis was used in the Chinese Journal of Gastrointestinal Surgery since it was founded till July, 2014. Manual retrieval was also conducted. Two researchers independently screened for literature and extracted data. Qualities on methodologies or on the processes of reporting and reviewing were evaluated by both AMSTAR and PRISMA scales. Forty-two papers on meta-analyses were included in this study. Results on the quality of methodology evaluation showed that the lowest and highest scores were 6 and 9 respectively, the median score was 7. Two articles (4.8%) were rated as high, 40 articles (95.2%) as moderate and 0 articles (0%) as low. Although the quality of methodology was above the average, however, there were still some problems seen in some papers as the conflict of interest was not stated, the list of studies (included and excluded) was not provided, a comprehensive literature search was not performed, the likelihood of publication bias was not assessed, etc. Results on the quality of reporting evaluation showed that the lowest and highest scores were 14 and 22 respectively, the average score was 18.43 ± 2.03, 3 articles (7.1%) scored less than 15 points, 35 articles (83.3%) scored 15.5-21 points, and 4 articles (9.6%) scored 21.5-27 points. The included reviews had high quality on the titles of the report, inclusion criteria, rationale of introduction, synthesis of results, results of individual. However, the abstract, objectives of introduction, scheme and registered, inclusion criteria, research screening, additional analysis, conclusion limitations, funding support etc. were lack of comprehensive reports. Articles on Meta-analysis published in the Chinese Journal of Gastrointestinal Surgery are of high quality. The Chinese Journal of Gastrointestinal Surgery can provide better evidence for clinical decision to gastrointestinal surgeons. However, both of qualities on methodology and reports sill call for continuous improvement.

Anabolic steroids for rehabilitation after hip fracture in older people.

Anabolic steroids for rehabilitation after hip fracture in older people.

Candidate genes for aggression and antisocial behavior: a meta-analysis of association studies of the 5HTTLPR and MAOA-uVNTR.

Variation in central serotonin levels due to genetic mutations or experimental modifications has been associated with the manifestation of aggression in humans and animals. Many studies have examined whether common variants in serotonergic genes are implicated in aggressive or antisocial behaviors (ASB) in human samples. The two most commonly studied polymorphisms have been the serotonin transporter linked polymorphic region of the serotonin transporter gene (5HTTLPR) and the 30 base pair variable number of tandem repeats of the monoamine oxidase A gene (MAOA-uVNTR). Despite the aforementioned theoretical justification for these polymorphisms, findings across studies have been mixed and are thus difficult to interpret. A meta-analysis of associations of the 5HTTLPR and MAOA-uVNTR with ASB was conducted to determine: (1) the overall magnitude of effects for each polymorphism, (2) the extent of heterogeneity in effect sizes across studies and the likelihood of publication bias, and (3) whether sample-level or study-level characteristics could explain observed heterogeneity across studies. Both the 5HTTLPR and the MAOA-uVNTR were significantly associated with ASB across studies. There was also significant and substantial heterogeneity in the effect sizes for both markers, but this heterogeneity was not explained by any sample-level or study-level characteristics examined. We did not find any evidence for publication bias across studies for the MAOA-uVNTR, but there was evidence for an oversampling of statistically significant effect sizes for the 5HTTLPR. These findings provide support for the modest role of common serotonergic variants in ASB. Implications regarding the role of serotonin in antisocial behavior and the conceptualization of antisocial and aggressive phenotypes are discussed.

Abstract P1-08-08: Tumor infiltrating lymphocytes (TILs) in breast cancer: A meta-analysis of response to neoadjuvant chemotherapy based on TIL status

Abstract Background: TILs involving tumor and/or its associated stroma may be indicative of an immune response that may either facilitate anti-tumor immunity and clearance or immune tolerance and evasion. In this study we performed a meta-analysis evaluating the relationship between TILs and pathologic response to neoadjuvant chemotherapy (NAC) since this is considered as a surrogate endpoint of disease outcomes in ER negative or Her2 positive tumors. Methods: We searched PubMed and Embase (1991-May 2013), and ASCO abstracts (2009-2012), using a combination of free text search and controlled vocabulary search. We identified 1147 reports which met our initial search criteria, and they were reviewed to identify those which met the following criteria: (1) evaluated the presence of TILs, defined as tumor and/or stromal lymphocytes (CD4, CD8 or FOXP3) identified by H&amp;E, IHC or gene expression before NAC, (2) classified TIL's “high/low” or “positive/negative”, and (3) correlated TILs with pathological complete response (pCR) or near pCR after NAC. Standard anthracycline-containing regimens were used as NAC in most studies, and anti-HER2 therapy was not used in most studies with HER2-positive disease. Results are presented as pooled odds ratios (OR) with 95% confidence intervals (CI), based on random-effects (to account for between study variance and heterogeneity due to different cutoffs and subtypes of T lymphocytes). Sensitivity analysis was done and publication bias was investigated using a funnel plot. We employed the Chi(2) test and calculated the I(2) statistic to investigate study heterogeneity. Meta-analysis statistics were calculated using StatsDirect Version 2.7.9. Results: Seven studies including 1641 patients met our criteria for inclusion in this analysis. A TIL ratio classified as either high or positive was associated with a significantly higher likelihood of achieving a pCR/near pCR after NAC (OR 3.68; 95% CI 1.93–7.01. p&amp;lt;0.0001) [Table 1]. This effect was driven mainly by a difference in ER negative tumors (OR 4.04, 95% CI 2.16-7.57. p&amp;lt;0.0001) and Her2 positive tumors (OR 5.61, 95% CI 1.8–17.47, p = 0.0007); the association was present, but nonsignificant, in ER positive tumors (OR 2.17, 95% CI 0.95-4.98). Sensitivity analyses did not change the inference. Funnel plots suggested low likelihood of publication bias (Harbord Egger test, p = 0.604) for all studies, and the I(2) statistic was 67.5%. Table 1. Characteristics and Odds ratio for individual subtypesSubtypeNNo of studiesTIL low pCR%TIL high pCR%OR95% CIAll1641712.5%28.6%3.681.93 -7.01ER-/PR- and HER2- [except one study defined by ER-/PR-]403423.6%41.3%4.042.16 - 7.57Her2+326316.9%23.4%5.611.80 - 17.47ER/PR+55825.6%11.5%2.170.95 - 4.98 Conclusions: In this systematic review and meta-analysis, high or positive TIL status before NAC was associated with a significantly better pathologic response to NAC (surrogate for DFS and OS), particularly in patients with ER/PR-negative or HER2-overexpressing disease. Patients with tumors characterized by low or absent TILs require novel therapeutic approaches, and may be candidates for immunotherapeutic approaches to enhance innate immunity or reverse immune tolerance. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-08-08.

The relationship of Helicobacter pylori infection and colon neoplasia, on the basis of meta-analysis

Helicobacter pylori is an important causative factor in gastric carcinogenesis. However, its role in extragastric gastrointestinal malignancies, such as colon neoplasia, is controversial. The aim of this study was to explore the relationship of H. pylori infection with colon neoplasia by meta-analysis of all relevant studies. Pooled estimates were obtained using fixed or random-effects models as appropriate. Heterogeneity between studies was evaluated using the Cochran Q-test, whereas the likelihood of publication bias was assessed by constructing funnel plots. Among 238 potentially relevant studies, 210 were rejected as unsuitable and 28 studies were finally eligible for meta-analysis, including a total of 33 sets of data (17 on colon cancer and 16 on colon polyps). There was evidence of heterogeneity (I=57.37%); thus, the random-effects model of meta-analysis was chosen, showing pooled odds ratio (OR) equal to 1.41 [95% confidence interval 1.24-1.60, P=0.000]. The subgroup meta-analyses showed a significant relationship between H. pylori and colon cancer as well as colon polyps [OR 1.3 (1.07-1.59), P=0.01 and OR 1.5 (1.26-1.79), P=0.000, respectively]. The results of this meta-analysis showed a modest statistically significant relationship of H. pylori infection with both colon cancer and polyps.

A flood tide of systematic reviews on endodontic posts: methodological assessment using of R-AMSTAR

To help the dental practitioner solve a specific clinical problem, systematic reviews (SRs) are seen as the best guide. In addition to the unmanageable quantity of SRs, however, one should be aware of their variable quality. The present review describes the methodological quality of SRs on postendodontic restorations to work out the value of these reviews for the dental practitioner. SRs were searched in April 2012, independently and in triplicate. Post survival was used as measure of outcome. The methodological quality of included SRs was assessed with the Revised Assessment of Multiple Systematic Reviews (R-AMSTAR) checklist. Kappa statistics were used to assess reviewer agreement. Three hundred sixty-three papers were retrieved from the initial search. Ten SRs were included. One SR achieved a high R-AMSTAR score, whereas the other nine SRs achieved scores that indicate a substantial lack of methodological quality. Especially the items "grey literature," "combination of findings," "likelihood of publication bias," and conflict of interest" showed low R-AMSTAR scores. The three reviews with the highest R-AMSTAR scores tended to conclude that fewer failures occurred when using nonmetal posts. The reviewer agreement was excellent (kappa ranged from 0.79 to 0.85) in the R-AMSTAR classification. The approach presented revealed a lack of SRs with high methodological quality. Thus, no decisive conclusion can be drawn with respect to this topic. It appears that there is a trend for the superiority of fiber-reinforced posts. SRs must be of high methodological quality. This can be achieved by taking into consideration the results of this review. Improved methodological quality would make SRs more supportive for the general practitioner.

Helicobacter pylori infection and gastric histology in first-degree relatives of gastric cancer patients: a meta-analysis

Helicobacter pylori (H. pylori) is believed to predispose to gastric cancer by inducing the precancerous changes, that is, atrophy and intestinal metaplasia (IM). First-degree relatives of patients with gastric cancer might be at an increased risk of developing gastric cancer. However, this evidence is based on the scattered individual studies. The aim of this study was to examine the risk of first-degree relatives developing gastric cancer, in comparison with controls that have no family history of gastric cancer, by meta-analyzing all relevant studies. Extensive English language medical literature searches for human studies were performed up to the end of November 2009, using suitable keywords. Inclusion and exclusion criteria were identified and in eligible studies data on three parameters, that is, H. pylori prevalence, atrophy and IM, were extracted. Pooled estimates (odds ratio with 95% confidence intervals) were obtained using either the fixed or random-effects model as appropriate. 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 Egger's regression asymmetry test. Out of 155 initially identified studies, 11 studies, from various countries, fulfilling the inclusion criteria, examined the risk of first-degree relatives developing gastric cancer (n=1500) in comparison with controls (n=2638). For H. pylori prevalence, the pooled odds ratio with 95% confidence interval was 1.925 (1.419-2.611) and the test for overall effect Z was 4.211 (P=0.000). The respective values for atrophy and IM were 2.200 (1.266-3.824), Z=2.797, (P=0.005) and 1.982 (1.363-2.881), Z=3.582 (P=0.000) respectively. The results of this meta-analysis showed that first-degree relatives of patients with gastric cancer might be at an increased risk of developing gastric cancer, as judged by significantly higher prevalence of H. pylori, gastric atrophy and IM, in comparison with controls. Consequently, H. pylori detection and prophylactic eradication of the infection should be offered to such individuals. However, follow-up studies are required to prove the above.

The relation of α-linolenic acid to the risk of prostate cancer: a systematic review and meta-analysis

Backgroundα-Linolenic acid (ALA; 18:3n-3) has been associated inconsistently with an increased risk of prostate cancer. Additional studies have become available since the publication of 2 previous meta-analyses. Objective:The objective was to review the published data on the relation between ALA and prostate cancer. Design:We conducted a systematic review to identify studies that included data on ALA and risk of prostate cancer. Data were pooled from studies that compared the highest ALA quantile with the lowest ALA quantile, and risk estimates were combined by using a random-effects model. Results:The relation between ALA and prostate cancer is inconsistent across studies. We pooled data from 8 case-control and 8 prospective studies. The summary estimate revealed that high ALA dietary intakes or tissue concentrations are weakly associated with prostate cancer risk (relative risk [RR]: 1.20; 95% CI: 1.01, 1.43). When examined by study type (ie, retrospective compared with prospective or dietary ALA compared with tissue concentration) or by decade of publication, only the 6 studies examining blood or tissue ALA concentrations revealed a statistically significant association. With the exception of these studies, there was significant heterogeneity and evidence of publication bias. After adjustment for publication bias, there was no association between ALA and prostate cancer (RR: 0.96; 95% CI: 0.79, 1.17). Conclusions:Studies examining the relation between ALA and prostate cancer have produced inconsistent findings. High ALA intakes or high blood and adipose tissue concentrations of ALA may be associated with a small increased risk of prostate cancer. However, these conclusions are qualified because of the heterogeneity across studies and the likelihood of publication bias.

A Meta-Analysis to Evaluate Results of Colon Capsule Endoscopy Trials

Background: Small intestine capsule endoscopy (CE) is a well evaluated method for non-invasive detection of small-bowel disease. However, colon CE is more recent and so far only scattered trials evaluating its efficacy, in comparison to established colon diagnostic methods, exist. Aims: The aim of the present study therefore was to meta-analyse the data of existing colon CE trials to help determine the yield and miss rate of this new diagnostic modality. Methods: Extensive English language medical literature searches for human studies were performed up to the end of October 2008, using suitable keywords. Inclusion and exclusion criteria were identified and in eligible studies data on four parameters, i.e. sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV), were extracted. Pooled estimates with 95% confidence intervals (CI) were obtained using either the fixed or random-effects model as appropriate. 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 adjusted rank correlation test. Results: Out of 82 initially identified studies, in 4 studies which fulfilled the inclusion criteria, 465 individuals were studied. Capsules were expelled within 10 hours post ingestion in 85.3% (95% CI 66.3-94.5) of the individuals. The pooled data showed CE sensitivity 67.2% (95% CI 62.7-71.3), specificity 75.3% (64.8-83.5), PPV 67.8% (59.5-75.2) and NPV 77% (73-80.6). Conclusion: The results of this meta-analysis showed that colon CE is a promising alternative method for colon investigation, including screening for polyps and colorectal cancer.

Risk of colorectal neoplasm in patients with acromegaly: A meta-analysis

To examine the risk of colorectal neoplasm in acromegalic patients by meta-analyzing all relevant controlled studies. Extensive English language medical literature searches for human studies, up to December 2007, were performed using suitable keywords. Pooled estimates [odds ratio (OR) with 95% confidence intervals (CI)] were obtained using either the fixed or random-effects model as appropriate. 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 adjusted rank correlation test. For hyperplastic polyps the pooled ORs with 95% CI were 3.557 (2.587-4.891) by fixed effects model and 3.703 (2.565-5.347) by random effects model. The Z test values for overall effect were 7.81 and 6.984, respectively (P < 0.0001). For colon adenomas the pooled ORs with 95% CI were 2.486 (1.908-3.238) (fixed effects model) and 2.537 (1.914-3.364) (random effects model). The Z test values were 6.747 and 6.472, respectively (P < 0.0001). For colon cancer the pooled OR with 95% CI was identical for both fixed and random effects model (OR, 4.351; 95% CI, 1.533-12.354; Z = 2.762, P = 0.006]. There was no significant heterogeneity and no publication bias in all the above meta-analyses. Acromegaly is associated with an increased risk of colorectal neoplasm.

Relationship Between Helicobacter pylori Infection and Esophageal Neoplasia: A Meta-analysis

Helicobacter pylori is an important causative factor in gastric carcinogenesis. However, its role in extragastric gastrointestinal malignancies, such as esophageal cancer, is controversial. The aim of this study was to explore the relationship of H. pylori infection and H. pylori cagA-positive strain with this malignancy by performing meta-analysis of all relevant studies. Extensive MEDLINE English language medical literature searches for human studies were performed through February 2007 with suitable keywords. Pooled estimates were obtained by using fixed or random-effects model as appropriate. 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. In adenocarcinoma patients there were inverse significant relationships with both the H. pylori prevalence (pooled odds ratio [OR], 0.52; 95% confidence interval [CI], 0.37-0.73; P < .001) and the prevalence of H. pylori cagA-positive strain (pooled OR, 0.51; 95% CI, 0.31-0.82; P = .006). Similarly in patients with Barrett's esophagus there were inverse significant relationships (pooled OR, 0.64; 95% CI, 0.43-0.94; P = .025 and pooled OR, 0.39; 95% CI, 0.21-0.76; P = .005, respectively). In patients with squamous cell carcinoma there were no significant relationships with both H. pylori prevalence (pooled OR, 0.85; 95% CI, 0.55-1.33; P = .48) and the prevalence of H. pylori cagA-positive strains (pooled OR, 1.22; 95% CI, 0.7-2.13; P = .48). The results showed an inverse statistically significant relationship of H. pylori infection with both esophageal adenocarcinoma and Barrett's esophagus, which might suggest a protective role of the infection in these entities. On the contrary, no statistically significant relationship with squamous cell carcinoma was found.

Oral vasoactive medication in intermittent claudication: utile or futile?

To evaluate the role of orally administered vasoactive medication in the management of intermittent claudication. We limited our study to the products on the market in Belgium: cinnarizine, cyclandelate, isoxsuprine, naftidrofuryl, pentoxifylline, xanthinol nicotinate and buflomedil. We conducted a systematic literature search involving Medline, International Pharmaceutical Abstracts, the Cochrane Library, direct contact with marketing companies and key authors, snowballing and Science Citation Index search. We looked for randomised placebo-controlled trials (RCTs) in patients with Fontaine stage II, in which pain-free and/or maximal walking distance were measured using a standardised exercise test. For isoxsuprine and xanthinol nicotinate, no trials conforming to these criteria were found. Thirty-six trials on cinnarizine, cyclandelate, buflomedil, naftidrofuryl and pentoxifylline met our inclusion criteria. After quality assessment, 26 trials were excluded, mainly because of short trial duration (less than 12 weeks), small sample size (less than 30 patients) and/or failure to report details on variability (standard deviation or confidence limits). For cinnarizine and cyclandelate, none of the three selected RCTs was included. For buflomedil, of six published RCTs, two were included after quality assessment, each showing a marginally positive effect of buflomedil versus placebo. For naftidrofuryl, nine RCTs were selected; six were included of which five showed a significant positive result. The likelihood of publication bias and the heterogeneity of the results within and between trials precluded a meta-analysis. For pentoxifylline, of the 18 selected RCTs, only two could be included, both with inconclusive results. A national consensus conference, based on this review, concluded that health resources should be allocated to prevention and rehabilitation of intermittent claudication rather than to reimbursement of these products with doubtful efficacy.