• Title/Summary/Keyword: Meta study

Search Result 2,600, Processing Time 0.027 seconds

Current Evidence on the Relationship Between Two Polymorphisms in the NBS1 Gene and Breast Cancer Risk: a Meta-analysis

  • Zhang, Zhi-Hua;Yang, Lin-Sheng;Huang, Fen;Hao, Jia-Hu;Su, Pu-Yu;Sun, Ye-Huan
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.13 no.11
    • /
    • pp.5375-5379
    • /
    • 2012
  • Introduction: Published studies on the association between Nijmegen breakage syndrome 1(NBS1) gene polymorphisms and breast cancer risk have been inconclusive, and a meta-analysis was therefore performed for clarification. Methods: Eligible articles were identified by a search of MEDLINE and EMBASE bibliographic databases for the period up to March 2012. The presence of between-study heterogeneity was investigated using the chi-square-based Cochran's Q statistic test. When there was statistical heterogeneity, the random effects model was chosen; otherwise, fixed effects estimates were reported as an alternative approach. Results: A total of 11 eligible articles (14 case-control studies) were identified, nine case-control studies were for the 657del5 mutation (7,534 breast cancer cases, 14,034 controls) and five case-control studies were for the I171V mutation (3,273 breast cancer cases, 4,004 controls). Our analysis results indicated that the 657del5 mutation was associated with breast cancer risk (carriers vs. non-carriers: pooled OR =2.63, 95% CI: 1.76-3.93), whereas the I171V mutation was not (carriers vs. non-carriers: pooled OR =1.52, 95% CI: 0.70-3.28). Conclusion: The present meta-analysis suggests that the 657del5 gene mutation in the NBS1 gene plays a role in breast cancer risk, while the I171V mutation does not exert a significant influence.

Association between Cigarette Smoking and RASSF1A Gene Promoter Hypermethylation in Lung Cancer Patients: a Meta-analysis

  • Wu, Xiao-Ming;Chen, Yu;Shao, Yang;Zhou, Xiao-Long;Tang, Wen-Ru
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.19
    • /
    • pp.8451-8454
    • /
    • 2014
  • Objectives: Epidemiological studies have shown that molecular mechanisms underlying the development of lung cancers differ between smokers and unsmokers. Aberrant promoter methylation in some tumor suppressor genes is frequent in lung tumors from smokers but rare in those from non-smokers. Recently, many studies have investigated the association between cigarette smoking and RASSF1A gene promoter hypermethylation in lung cancer patients, but a unanimous conclusion could not be reached. We therefore performed this meta-analysis to derive a more precise estimation of any association. Study Design: An electronic search of PubMed and Chinese Biomedicine databases was conducted to select studies. A total of 19 case-control studies were chosen, and odds ratios (ORs) with confidence intervals (CIs) were used to assess the strength of associations. Results: The case-control studies covered 2, 287 lung cancer patients: 63.4%(1449) of the patients were smokers, 36.6% (838) were unsmokers. The overall results suggested that smokers with lung cancer had a 1.297-fold (95% CI: 1.066~1.580, p=0.010, p=0.087) higher risk for RASSF1A gene hypermethylation than the non-smokers. In the stratified analysis, an increased risk of RASSF1A gene hypermethylation in smokers than in non-smokers was found in Asian (OR=1.481, 95%CI: 1.179~1.861, p=0.001, p=0.186). Conclusions: This meta-analysis supports the idea that RASSF1A gene hypermethylation is associated with cigarette smoking-induced lung cancer.

Effects of Dietary and Physical Activity Interventions on Metabolic Syndrome: A Meta-analysis (대사증후군에 대한 식이와 운동 효과에 대한 메타분석)

  • Lee, Guna;Choi, Hye-Young;Yang, Sook-Ja
    • Journal of Korean Academy of Nursing
    • /
    • v.45 no.4
    • /
    • pp.483-494
    • /
    • 2015
  • Purpose: This study identified effects of dietary and physical activity interventions including dietary interventions or physical activity interventions alone or combined dietary-physical activity interventions to improve symptoms in metabolic syndrome including abdominal obesity, high triglycerides, low high density lipoprotein cholesterol, elevated blood pressure, and elevated fasting glucose through meta-analysis. Methods: Articles on metabolic syndrome X published from 1988 to 2013 were searched through electronic databases, Google Scholar, and reference reviews. Methodological quality was assessed by the checklist, SIGN (Scottish Intercollegiate Guidelines Network). Results: In the meta-analysis, there were 9 articles reporting 13 interventions with 736 participants. Using random effect models, the dietary and/or physical activity interventions showed a lower mean difference in waist circumference ( - 1.30 cm, 95% CI: - 2.44~ - 0.15, p=.027). The combined dietary-physical activity interventions showed a lower mean difference in waist circumference ( - 2.77 cm, 95% CI: - 4.77~ - 0.76, p=.007) and systolic blood pressure ( - 5.44 mmHg, 95% CI: - 10.76~ - 0.12, p=.044). Additionally, interventions of over 24 weeks yielded a lower mean difference in waist circumference ( - 2.78 cm, 95% CI: - 4.69~ - 0.87, p=.004) and diastolic blood pressure ( - 1.93 mmHg, 95% CI: - 3.63~ - 0.22, p=.026). Conclusion: The findings indicate that dietary and/or physical activity interventions for metabolic syndrome reduce central obesity with no adverse effects. This finding provides objective evidences for dietary and physical activity management on metabolic syndrome as an efficient intervention.

Outcomes of comprehensive fixed appliance orthodontic treatment: A systematic review with meta-analysis and methodological overview

  • Papageorgiou, Spyridon N.;Hochli, Damian;Eliades, Theodore
    • The korean journal of orthodontics
    • /
    • v.47 no.6
    • /
    • pp.401-413
    • /
    • 2017
  • Objective: The aim of this systematic review was to assess the occlusal outcome and duration of fixed orthodontic therapy from clinical trials in humans with the Objective Grading System (OGS) proposed by the American Board of Orthodontics. Methods: Nine databases were searched up to October 2016 for prospective/retrospective clinical trials assessing the outcomes of orthodontic therapy with fixed appliances. After duplicate study selection, data extraction, and risk of bias assessment according to the Cochrane guidelines, random-effects meta-analyses of the mean OGS score and treatment duration were performed and 95% confidence intervals (CIs) were calculated. Results: A total of 34 relevant clinical trials including 6,207 patients (40% male, 60% female; average age, 18.4 years) were identified. The average OGS score after treatment was 27.9 points (95% CI, 25.3-30.6 points), while the average treatment duration was 24.9 months (95% CI, 24.6-25.1 months). There was no significant association between occlusal outcome and treatment duration, while considerable heterogeneity was identified. In addition, orthodontic treatment involving extraction of four premolars appeared to have an important effect on both outcomes and duration of treatment. Finally, only 10 (39%) of the identified studies matched compared groups by initial malocclusion severity, although meta-epidemiological evidence suggested that matching may have significantly influenced their results. Conclusions: The findings from this systematic review suggest that the occlusal outcomes of fixed appliance treatment vary considerably, with no significant association between treatment outcomes and duration. Prospective matched clinical studies that use the OGS tool are needed to compare the effectiveness of orthodontic appliances.

A Study on Metadata Development for Establishing International Research Cooperation Information Database (국제연구협력정보 DB 구축을 위한 메타데이터 개발에 관한 연구)

  • Noh, Younghee
    • Journal of the Korean BIBLIA Society for library and Information Science
    • /
    • v.29 no.2
    • /
    • pp.5-34
    • /
    • 2018
  • In this research, we intended to discover all types of information related to international research cooperation, collect information by each type, and build a database. To this end, we initially developed metadata, discussed with metadata experts to develop metadata in the primary phase, and conducted a survey on the experts related to international research cooperation. Furthermore, we collected and entered data in the meta field for each type of information source, and verified the meta field through processes such as the existence of actual data for each meta field, among others. The types of database designed in this research are the international research cooperation information source database, international research cooperation project database, international research cooperation expert database, international research cooperation institution database, international organization database, and other database, and as a result of validating of the field by entering the data by conducting the survey, the survey results and the data entry rate by field demonstrated such a high rate of consistency. However, only the international organization data field was confirmed to have approximately 25% of the field having the data entry rate of less than 10% despite the high rate of significance rated by the users.

Radiation Exposure and Cancer Mortality Among Nuclear Power Plant Workers: a Meta-analysis (원전종사자의 방사선 노출과 암사망 위험도와의 관련성에 대한 메타분석)

  • Park, Eun-Sook;Moon, Ki-Eun;Kim, Han-Na;Lee, Won-Jin;Jin, Young-Woo
    • Journal of Preventive Medicine and Public Health
    • /
    • v.43 no.2
    • /
    • pp.185-192
    • /
    • 2010
  • Objectives: We conducted a meta-analysis to investigate the relationship between low external doses of ionizing radiation exposure and the risk of cancer mortality among nuclear power plant workers. Methods: We searched MEDLINE using key words related to low dose and cancer risk. The selected articles were restricted to those written in English from 1990 to January 2009. We excluded those studies with no fit to the selection criteria and we included the cited references in published articles to minimize publication bias. Through this process, a total of 11 epidemiologic studies were finally included. A publication bias was tested for using Egger's test. The homogeneity test was performed before the integration of each of the standardized mortality ratios (SMRs) and the result proved that the studies were heterogeneous. Results: We found significant decreased deaths from all cancers (SMR = 0.75, 95% CI = 0.62 - 0.90), all cancers excluding leukemia, solid cancer, mouth and pharynx, esophagus, stomach, rectum, liver and gallbladder, pancreas, lung, prostate, lymphopoietic and hematopoitic cancer. The findings of this meta-analysis were similar with those of the 15 Country Collaborative Study conducted by the International Agency for Research on Cancer. A publication bias was found only for liver and gallbladder cancer (p = 0.015). Heterogeneity was observed for all cancers, all cancers excluding leukemia, solid cancer, esophagus, colon and lung cancer. Conclusions: Our findings of low mortality for stomach, rectum, liver and gallbladder cancers may explained by the health worker effect. Yet further studies are needed to clarify the low SMR of cancers, for which there is no useful screening tool, in nuclear power plant workers.

Meta-analysis on the Blood Lipids as Risk Factors of Coronary Heart Diseases in Koreans (한국인 관상동맥성 심질환의 위험요인으로서 혈청지질에 관한 메타분석)

  • Kim, Ki-Soon;Kim, Yang-Ok;Park, Jong;Park, Jong-Ku;Kim, Chun-Bae;Jee, Sun-Ha;Ryu, So-Yeon
    • Journal of Preventive Medicine and Public Health
    • /
    • v.32 no.4
    • /
    • pp.491-498
    • /
    • 1999
  • Objectives : To determine the relations between seven blood lipids such as total cholesterol(TC), triglyceride(TG), HDL-cholesterol(HDL), LDL-cholesterol(LDL), apolipoprotein A-1(Apo A1), apolipoprotein B(Apo B) and lipoprotein(a)(Lp(A)) and the coronary heart diseases(CHD), the quantitative techniques of meta-analysis were applied to studios of blood lipids and CHD in Koreans. Methods : We searched the Korean and the English literature published from 1980 to August, 1997 by manual search and bibliography review. Information on sample size, study design, participant characteristics(gender, age) and blood lipid levels were abstracted by reviewers using inclusion criteria. Estimates of the effect sizes of blood lipid levels on CHD in Koreans and corresponding 95% confidence intervals were calculated using random-effect models. Results : We identified 16 case-control studies to apply meta-analysis. The overall effect sizes for CHD were 20.3(95% CI: 14.23-20.22) in TC, 24.8(95% CI: 12.6-36.86) in TG, 15.16(95% CI: 3.99-26.33) in LDL, -3.48(95% CI: -5.79 - -1.17) in HDL, -9.78(95% CI: -16.98 - -2.58) in Apo-a1, 17.88(95% CI: 9.72-26.05) in Apo B and 18.95(95% CI: 17.88-20.02) in Lp(a). Conclusions : Our results suggested that seven blood lipids were significantly associated with CHD in Koreans. Well-designed and prospective studies between blood lipids and CMD in Koreans should be peformed.

  • PDF

A Study on the Relationship between Public Subsidies and Private R&D Expenditure: A Meta-Regression Analysis of the Econometric Evidence (정부보조금의 민간R&D투자에 대한 관계: 계량경제학적 문헌에 대한 메타회귀분석)

  • Kim, Ho;Kim, Byung-Keun
    • Journal of Technology Innovation
    • /
    • v.19 no.3
    • /
    • pp.141-174
    • /
    • 2011
  • This paper presents the results of a meta-regression analysis on econometric evidence concerning the relationship between public funding of R&D and private R&D expenditure by reviewing literature and synthesizing existing results. The analysis on the effects of public financing on private investments in R&D has been the object of numerous studies, none of which having arrived at definite conclusion. A meta-analysis based upon a data-base including all relevant studies was carried out to examine whether the characteristics of the applied analysis influence the results. Three different empirical results are presented.

  • PDF

Development of the new meta-heuristic optimization algorithm inspired by a vision correction procedure: Vision Correction Algorithm (시력교정 과정에서 착안된 새로운 메타휴리스틱 최적화 알고리즘의 개발: Vision Correction Algorithm)

  • Lee, Eui Hoon;Yoo, Do Guen;Choi, Young Hwan;Kim, Joong Hoon
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.17 no.3
    • /
    • pp.117-126
    • /
    • 2016
  • In this study, a new meta-heuristic optimization algorithm, Vision Correction Algorithm (VCA), designed according to the optical properties of glasses was developed. The VCA is a technique applying optometry and vision correction procedure to optimization algorithm through the process of myopic/hyperopic correction-brightness adjustment-compression enforcement-astigmatism adjustment. The proposed VCA unlike the conventional meta-heuristic algorithm is an automatically adjusting global/local search rate and global search direction based on accumulated optimization results. The proposed algorithm was applied to the representative optimization problem (mathematical and engineering problem) and results of the application are compared with that of the present algorithms.

Meta-analysis of the Effects of Gifted-mathematics programs on Creativity Improvement (수학영재프로그램이 창의성 향상에 미치는 효과 메타분석)

  • Cho, Yun-Hee;Ko, Ho kyoung
    • Journal of Science Education
    • /
    • v.41 no.3
    • /
    • pp.499-518
    • /
    • 2017
  • In this study, the meta-analysis technique was applied to investigate the effectiveness of gifted-mathematics programs on development of creativity. Studies conducted the outcomes form the 20 studies were used for meta-analysis. Research questions are as follows; first, what is the overall effect size of the gifted mathematics programs on development of mathematical creativity. Second, what are effect sizes of sub-group(fluency, flexibility, originality) analysis. Third, compare the effect sizes of those in compliance with the grade and the class type. Results from data analysis are as follows. First, the overall effect size for studies related the gifted-mathematical programs was .66, which is high. Second, it was found that each sub-group differed from its effect on learning outcomes. Fluency(.76) was the highest of all, which was followed by flexibility(.60) and originality(.50) in a row. Lastly, the overall effect size for gifted elementary school students related the gifted-mathematical programs was .69, which is high than gifted middle school students was .46.