• Title/Summary/Keyword: publication bias

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Chorioamnionitis: Is a major player in the development of bronchopulmonary dysplasia?

  • Choi, Chang Won
    • Clinical and Experimental Pediatrics
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    • v.60 no.7
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    • pp.203-207
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    • 2017
  • Chorioamnionitis is an inflammation in the fetal membranes or placenta. When chorioamnionitis develops, fetal lungs are exposed to inflammatory cytokines and mediators via amniotic fluid. Because inflammation plays a pivotal role in the development of bronchopulmonary dysplasia (BPD), a chronic lung disease of prematurity, fetal lung inflammation induced by chorioamnionitis has been considered to be one of the major pathogenetic factors for BPD. Although there have been a number of studies that demonstrated the relationship between chorioamnionitis and BPD, there are still controversies on this issue. The controversies on the relationship between chorioamnionitis and BPD arise from not-unified definitions of chorioamnionitis and BPD, different study populations, and the proportion of contribution between inflammation and infectious microorganisms. The publication bias also contributes to the controversies. Clinical trials targeting chorioamnionitis or microorganisms that cause chorioamnionitis will answer on the actual relationship between chorioamnionitis and BPD and provide a novel prophylactic strategy against BPD based on that relationship.

The Effects of Hardiness : A Meta-Analysis of Korean Nursing Research Findings (국내 강인성 효과 연구결과에 대한 메타분석)

  • Kim, Young Ock
    • Korean Journal of Adult Nursing
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    • v.17 no.5
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    • pp.783-792
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    • 2005
  • Purpose: This study was conducted to meta-analyze the effects of hardiness on health-related variables. Method: After review of 19 studies performed by Korean nurses, research variables, statistical data(r or F), and other methodological data were extracted and coded. Research variables were categorized under 5 groups such as health-related behavior, well-being, adaptation, stress, and support according to conceptual similarity. Using SAS program, 20 research variables and 34 effect sizes were calculated after eliminating heterogeneous data by Q-test, Results: Effects of hardiness on whole research variables was .512 and ranged from .322 to .643 by categories. The greatest effect was obtained from well-being category, whereas the smallest effect from stress category. All effect sizes were statistically significant. But fail-safe numbers were small and failed to achieve reasonable tolerance level. Conclusion: Results of meta-analysis indicated that hardiness has a moderate effect on health-related variables. But for improving the reliability of the results by minimizing publication bias, the more hardiness studies should be done.

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Meta-analysis in dental research (치의학 분야에서의 메타 분석)

  • Lim, Hoi-Jeong
    • The Journal of the Korean dental association
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    • v.52 no.8
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    • pp.478-490
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    • 2014
  • Recently, importance of meta-analysis is increasing in the field of dentistry, since it is not easy to settle controversies arising from conflicting studies. Meta-analysis is the statistical method of combining results from two or more individual studies that have been done on the same topic. Merits of meta-analysis include an increase in power, an improvement in precision, and the ability to address solution not provided by individual studies. However, it might mislead researchers when variation across studies and publication bias are not carefully taken into consideration. The purpose of this study is to help understand meta-analysis by making use of individual results in dental research paper.

A meta-analysis of the effects of post-traumatic stress disorder intervention programs on firefighters (소방공무원의 외상 후 스트레스 장애 중재 프로그램 효과에 관한 메타분석)

  • Kang, Min-Ju
    • The Korean Journal of Emergency Medical Services
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    • v.23 no.2
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    • pp.33-42
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    • 2019
  • Purpose: This study aimed to identify the effects of post-traumatic stress disorder intervention programs on firefighters through a meta-analysis. Methods: Seven studies were selected for meta-analysis. The overall average effect size, effect sizes for each intervention variables, and publication bias were analyzed using Comprehensive Meta-Analysis(CMA) version 2.0 (Biostat, Englewood, NJ, USA). Results: Post-traumatic stress disorder intervention programs were found to have a very low, not statistically significant effect (effect size=-.171, confidence interval=-0.361~0.019, Z=-1.768, p>.05). However, these programs was less than 50 (effect size=-.622). Conclusion: The results of this study suggest that further research on the effects of post-traumatic stress disorder intervention among firefighters is needed in order to develop more effective programs.

A meta-analysis on the correlation of factors related to major satisfaction of paramedic students (응급구조(학)과 학생의 전공만족도 관련 요인에 관한 연구)

  • Min-Ju Kang;Mi-Young Choi;Jeong-Mi Ju
    • The Korean Journal of Emergency Medical Services
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    • v.27 no.1
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    • pp.31-41
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    • 2023
  • Purpose: This study was conducted to analyze variables related to paramedic students' major satisfaction comprehensively and present development plans to improve major satisfaction. Methods: Five studies were selected for analysis. The overall average effect size, effect sizes for each related variable, and publication bias were analyzed using Comprehensive Meta-Analysis (CMA) version 2.0 (Biostat, Englewood, NJ, USA). Results: Various known variables related to major satisfaction were found to have little correlation, and paramedic students' major satisfaction were highly correlated variables, such as major commitment (ES=.781), and department adaptation (ES=.722). Conclusion: Research should be continuously conducted to examine additional variables correlated with the major satisfaction of paramedic students.

Heparanase mRNA and Protein Expression Correlates with Clinicopathologic Features of Gastric Cancer Patients: a Meta-analysis

  • Li, Hai-Long;Gu, Jing;Wu, Jian-Jun;Ma, Chun-Lin;Yang, Ya-Li;Wang, Hu-Ping;Wang, Jing;Wang, Yong;Chen, Che;Wu, Hong-Yan
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.18
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    • pp.8653-8658
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    • 2016
  • Background: Heparanase is believed to be involved in gastric carcinogenesis. However, the clinicopathologic features of gastric cancer with high heparanase expression remain unclear. Aim : The purpose of this study was to comprehensively and quantitatively summarize available evidence for the use of heparanase mRNA and protein expression to evaluate the clinicopathological associations in gastric cancer in Asian patients by meta-analysis. Materials and Methods: Relevant articles listed in MEDLINE, CNKI and the Cochrane Library databases up to MARCH 2015 were searched by use of several keywords in electronic databases. A meta-analysis was performed to clarify the impact of heparanase mRNA and protein on clinicopathological parameters in gastric cancer. Combined ORs with 95%CIs were calculated by Revman 5.0, and publication bias testing was performed by stata12.0. Results: A total of 27 studies which included 3,891 gastric cancer patients were combined in the final analysis. When stratifying the studies by the pathological variables of heparanase mRNA expression, the depth of invasion (633 patients) (OR=4.96; 95% CI=2.38-1.37; P<0.0001), lymph node metastasis (639 patients) (OR=6.22; 95%CI=2.70-14.34, P<0.0001), and lymph node metastasis (383 patients) (OR=6.85; 95% CI=2.04-23.04; P=0.002) were all significant. When stratifying the studies by the pathological variables of heparanase protein expression, this was the case for depth of invasion (1250 patients) (OR=2.76; 95% CI=1.52-5.03; P=0.0009), lymph node metastasis (1178 patients) (OR=4.79 ; 95% CI=3.37-6.80, P<0.00001), tumor size (727 patients) (OR=2.06 ; 95% CI=1.31-3.23; P=0.002) (OR=2.61; 95% CI=2.09-3.27; P=0.000), and TNM stage (1233 patients) (OR=6.85; 95% CI=2.04-23.04; P=0.002). Egger's tests suggested publication bias for depth of invasion, lymph node metastasis, lymph node metastasis and tumor size of heparanase mRNA and protein expression. Conclusions: This meta-analysis suggests that higher heparanase expression in gastric cancer is associated with clinicopathologic features of depth of invasion, lymph node metastasis and TNM stage at mRNA and protein levels, and of tumor size only at the protein level. Egger's tests suggested publication bias for these clinicopathologic features of heparanase mRNA and protein expression, and which may be caused by shortage of relevant studies. As a result, although abundant reports showed heparanase may be associated with clinicopathologic features in gastric cancer, this meta-analysis indicates that more strict studies were needed to evaluate its clinicopathologic significance.

Effect of High Dose Insulin/Euglycemia Therapy for Acute Calcium Channel Blocker Intoxication: A Systematic Review (급성 칼슘통로차단제 중독에서 고용량 인슐린/정상혈당치료의 효과: 체계적 고찰)

  • Yang, Jinmo;Ko, Dong Ryul;Kong, Taeyoung;Joo, Young Seon;You, Je Sung;Chung, Sung Phil
    • Journal of The Korean Society of Clinical Toxicology
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    • v.13 no.2
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    • pp.103-110
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    • 2015
  • Purpose: The purpose of this study is to evaluate the effectiveness and the adverse events of high dose insulin/euglycemia therapy in acute calcium channel blocker (CCB) poisoning. Methods: We developed a systematic search strategy and applied it to 4 electronic reference databases. We searched medical journals as well as the bibliographies of relevant articles. All forms of literature relevant to human use of high dose insulin for acute CCB poisoning were included. The literature search was conducted by two investigators in August, 2015 with publication language restricted to English and Korean. Case reports were divided between CCB overdose alone and multi-drug overdose including CCB. The effect and adverse event of high dose insulin and clinical outcome of each case were analyzed. Results: Among 55 searched studies, 20 studies were included. A prospective study, a retrospective study, a systematic review study, and 17 case reports were identified. Case reports consisted of 11 CCB alone and 12 multidrug overdose cases including CCB. Although most cases described significant clinical improvements, one of them showed no beneficial effect. Several adverse events including hypoglycemia and hypokalemia were reported. No significant sequalae from adverse events was reported. Conclusion: Although there were many case reports demonstrating successful use of high dose insulin for CCB poisoning, the effect cannot be estimated due to a possibility of publication bias. Therefore, high dose insulin/euglycemia therapy might be considered adjunctive therapy in cases of CCB intoxication refractory for standard therapy.

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Effect of Intravenous Lipid Emulsion in the Patient with Acute Poisoning : A Systematic Review (급성 중독 환자에서 지질 유탁액 정맥투여의 효과: 체계적 고찰)

  • Myung, Jinwoo;Ko, Dong Ryul;Kong, Taeyoung;Joo, Young Seon;You, Je Sung;Chung, Sung Phil
    • Journal of The Korean Society of Clinical Toxicology
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    • v.13 no.1
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    • pp.1-10
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    • 2015
  • Purpose: The purpose of this study was to evaluate the usefulness of intravenous lipid emulsion as well as adverse events in acute poisoning patients. Methods: Literature was accessed through PubMed, EMBASE, Cochrane library, Web of science, and KoreaMed. All forms of literatures relevant to human use of intravenous lipid emulsion for acute poisoning were included. Cases reports or letters without description of clinical outcomes for each case were excluded. The literature search was conducted by two investigators in March, 2015, with publication language restricted to English and Korean. The effect, onset time, and adverse event of lipid emulsion and final outcome of each case were analyzed. Results: Eighty-one published articles were included, excluding articles whose title and abstract were not relevant to this study. No articles were classified as high level of evidence. Sixty-eight case reports were identified, consisting of 25 local anesthetics and 43 other drugs, such as tricyclic antidepressants and calcium channel blockers. Although most cases described significant clinical improvements, some of them showed no beneficial effect or worsening of clinical course. Several adverse events including hyperamylasemia and laboratory interference were reported. Conclusion: Although there were many case reports illustrating successful use of lipid for various drug poisonings, the effect cannot be estimated due to significant possibility of publication bias. Therefore, lipids might be considered in severe hemodynamic instability resulting from lipophilic drug poisoning, however further studies should follow to establish the use of lipid as the standard of care.

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The Anti-hepatotoxic Effect of Ginseng in Rats: Meta-analysis

  • Kook, Se-Jeong;Han, Hye-Kyoung;Kim, Gun-Hee;Choi, Ki-Heon
    • Journal of Ginseng Research
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    • v.32 no.2
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    • pp.161-170
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    • 2008
  • The aim of this meta-analysis was to systematically investigate the anti-hepatotoxic effect of ginseng in rats induced toxicity which damage to liver. Primary researches were gained on the ScienceDirect database, the DBpia, and the KISS, and the data about the effect factors in plasma and in enzyme were listed as many as possible. The effect factors were alanine transaminase (ALT), aspartate transaminase (AST), liver aminopyrine N-demethylase (AD), liver aniline hydroxylase (AH), liver 3,4-Methylenedioxyamphetamine (liver MDA), cytochrome P450 (P450), serum alkaline phosphatase (ALP), serum lactate dehydrogenase (LDH), cytochrome b5 (Cyto b5), glutathione reductase (GR), Liver glutathione S-transferase (GST), liver glutamyltransferase (GT), Liver (${\gamma}-GCS$), serum liver 3,4-Methylenedioxyamphetamine (serum MDA), serum sorbitol dehydrogenase (SDH), serum total protein (TP), serum ${\gamma}-glutamyltransferase$ (${\gamma}-GT$). To investigate the effect of ginseng, the mean difference (MD) between the group of rats induced by toxicity (RH) and the group of rats induced by toxicity with ginseng (RHG) were combined, and the significance of MDs were tested. The combined MDs were checked the biases caused by heterogeneity among studies and the publication biases, and adjusted by using random effect model and trim and fill method, respectively. The effect about ALT, AST, ALP, LDH, SDH, TP and ${\gamma}-GT$ in plasma factors were significant, and about AD, liver MDA, P450, Cyto b5, GR, GST, GT and ${\gamma}-GCS$ in enzyme factors were significant. The treatment with ginseng supplementation was significantly effected on plasma and enzyme factors of damaged-rats.

Association between dental X-ray exposure and the thyroid cancer risk: A meta-analysis of case-control studies

  • Hwang, Su-Yeon;Kim, Hae-Young;Song, Sun-Mi;Choi, Eun-Sil
    • Journal of Korean society of Dental Hygiene
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    • v.20 no.3
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    • pp.269-279
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    • 2020
  • Objectives: Previous studies have reported inconsistent findings in the association between dental diagnostic X-ray exposure and thyroid cancer. This study was a meta-analysis of case-control studies evaluating the association between exposure to dental radiation and the thyroid cancer risk. Methods: We searched the PubMed and EMBASE databases to identify studies on dental radiation and thyroid cancer risks that were published up to September 2018. Quality of studies was assessed using the Newcastle-Ottawa scale. A fixed-effects model was used to estimate pooled odds ratios (ORs) and 95% confidence intervals (CIs) using STATA 14.0. Potential publication biases were evaluated using Egger's test and Begg's funnel plot. Results: From the literature search, we included six case-control studies in this meta-analysis. The meta-analysis using the fixed-effects model found that dental X-ray exposure was associated with 2.34 times increased risk for thyroid cancer (OR=2.34, 95% CI=1.79-3.21). There was no heterogeneity in the data (p=0.662, I2 =0%). Egger's test showed that there was no publication bias (p=0.532). Conclusions: This meta-analysis confirmed the association of dental X-ray exposure and thyroid cancer risk. The current results underscore the importance of applying safety regulations at dental clinics to protect thyroid glands during dental radiography examinations.