• Title/Summary/Keyword: Cochran Q Test

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A Round Robin Study of Solid Content Test and Applicability Estimation of FT-IR Analysis for Chemical Admixtures (다자비교시험을 통한 화학혼화제 고형분량 시험법의 신뢰성 및 FT-IR 분석에 대한 효용성 평가)

  • Kim, Jin-Cheol;Yoo, Hyeok-Jin;Kim, Hong-Sam;Park, Ko-Eun
    • Journal of the Korea Concrete Institute
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    • v.27 no.6
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    • pp.695-703
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    • 2015
  • Acceptance criteria for chemical admixtures of cement concrete were investigated in domestic and international specifications. The reliability was verified for solid content test method of chemical admixture examined statistical analysis by round robin test. The applicability of FT-IR spectroscopy for qualitative measurement of multi-compound chemical admixtures verified. From solid content experimental results, outlier analysed using Cochran, Grubbs and Dickson's Q test. Repeatability and reproducibility standard deviation for solid content results showed 0.25 and 0.098% respectively according to KS A ISO 5725-2 procedure, it can be confirmed reliability of test methods. FT-IR spectrum of liquefied or oven-dried chemical admixtures condition showed big differences. It is needed that the FT-IR analysis is performed on dry material. However there's no difference with the applicability of FT-IR spectroscopy for multi-compound chemical admixtures. So the utility of method analysis could not identify.

Verification on the Measurement Uncertainty for Surface Roughness (표면거칠기측정에 대한 측정불확도 추정방법)

  • Kim, Chang-Soon;Park, Min-Won
    • Journal of the Korean Society for Precision Engineering
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    • v.27 no.4
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    • pp.40-45
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    • 2010
  • Evaluation of uncertainty is an ongoing process that can consume time and resources. It can also require the service of someone who is familiar with data analysis techniques. Therefore, it is important for laboratory personnel who are approaching uncertainty analysis for the first time to be aware of the resources required. International inclination of measurement filed to guarantee the traceability and confidence of measurement results discards the error concept and instead analyzes the measurement uncertainty. In this paper, we analyzed the elements of measurement uncertainty on surface roughness test which are the important things in mechanical parts test. Repeat the test by 3 men, the measurement uncertainty could be calculated.

The Study of Validity in Active Movement Control test for Low Back Pain Patients with or without Hamstring Shortening (슬괵근 단축 유무에 따른 요통환자에 대한 능동적 움직임 조절 검사의 타당도 연구)

  • Oh, Se-Jun;Choi, Jong-Duk
    • Journal of the Korean Society of Physical Medicine
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    • v.7 no.4
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    • pp.443-450
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    • 2012
  • PURPOSE: This study was investigated to find the validity of active movement control test for low back pain patients with or without hamstring shortening. METHODS: The subjects of this study were 28 subjects and all of them agreed to participate in the study. All subjects were classified according to 4groups. Group1 was no LBP, no hamstring shortening. Group2 was no LBP, hamstring shortening. Group3 was LBP, no hamstring shortening. Group4 was LBP, hamstring shortening. We measured to see their low back pain and hamstring shortening with VAS, Goniometer for active movement control test. We analyzed the data using Cochran Q test and crosstabulation for agreement index. RESULTS: The results of this study were as follows : 1) Low back pain had effect on active movement control by Group1 and Group2. 2) Hamstring had effect on active movement control by Group1 and Group2 3)Low back pain with or without hamstring shortening had effect on active movement control by Group4 CONCLUSION: According the results of this study, active movement control test were significantly influenced on low back pain and hamstring interaction.

Physical and Psychospiritual Care Need by End-of-life Stages among Non-cancer Patient at Home: Based on the Importance and Difficulty of Care Need (재가 비암 환자의 생의 말기 단계별 신체적, 영적 간호요구도 - 간호요구의 중요도와 난이도를 중심으로 -)

  • Lee, Jong-Eun;Kim, Soon-Lae
    • Research in Community and Public Health Nursing
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    • v.23 no.2
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    • pp.127-133
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    • 2012
  • Purpose: This study was conducted to assess needs at each end-of-life care stage and to analyze importance and difficulty of care needs for home care nursing among non-cancer patients. Methods: We used a retrospective design. Total eligible patients were 117 at the ages of 40 and over, who continuously received home care nursing throughout beginning, stable, and near death stages, and finally died at home from January 1, 2006 to December 31, 2006. Descriptive statistics, Cochran's Q test, Friedman's test were used for data analysis. Results: In the area of physical care, the care need for 'assistance for activities in daily life' was significantly highest in the beginning stage. The care need for 'aggravation or adverse changes in physical symptoms' was significantly increased in the near death stage. In the area of psychospiritual care, 'family's psychological burden' was revealed as having the highest rate of care needs in the every stage. Conclusion: Future intervention should consider assessing care needs in end-of-life care for non-cancer patients who are provided with home care nursing.

The Diagnostic Performance of the Length of Tumor Capsular Contact on MRI for Detecting Prostate Cancer Extraprostatic Extension: A Systematic Review and Meta-Analysis

  • Tae-Hyung Kim;Sungmin Woo;Sangwon Han;Chong Hyun Suh;Soleen Ghafoor;Hedvig Hricak;Hebert Alberto Vargas
    • Korean Journal of Radiology
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    • v.21 no.6
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    • pp.684-694
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    • 2020
  • Objective: The purpose was to review the diagnostic performance of the length of tumor capsular contact (LCC) on magnetic resonance imaging (MRI) for detecting prostate cancer extraprostatic extension (EPE). Materials and Methods: PubMed and EMBASE databases were searched up to March 24, 2019. We included diagnostic accuracy studies that evaluated LCC on MRI for EPE detection using radical prostatectomy specimen histopathology as the reference standard. Quality of studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Sensitivity and specificity were pooled and graphically presented using hierarchical summary receiver operating characteristic (HSROC) plots. Meta-regression and subgroup analyses were conducted to explore heterogeneity. Results: Thirteen articles with 2136 patients were included. Study quality was generally good. Summary sensitivity and specificity were 0.79 (95% confidence interval [CI] 0.73-0.83) and 0.67 (95% CI 0.60-0.74), respectively. Area under the HSROC was 0.81 (95% CI 0.77-0.84). Substantial heterogeneity was present among the included studies according to Cochran's Q-test (p < 0.01) and Higgins I2 (62% and 86% for sensitivity and specificity, respectively). In terms of heterogeneity, measurement method (curvilinear vs. linear), prevalence of Gleason score ≥ 7, MRI readers' experience, and endorectal coils were significant factors (p ≤ 0.01), whereas method to determine the LCC threshold, cutoff value, magnet strength, and publication year were not (p = 0.14-0.93). Diagnostic test accuracy estimates were comparable across all assessed MRI sequences. Conclusion: Greater LCC on MRI is associated with a higher probability of prostate cancer EPE. Due to heterogeneity among the studies, further investigation is needed to establish the optimal cutoff value for each clinical setting.

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
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    • v.13 no.11
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    • pp.5375-5379
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    • 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.

Meta Analysis of Symptom Improvement through Eradication of Helicobacter pylori in Patients with Non-ulcer Dyspepsia (비궤양성 소화불량에서 Helicobacter pylori 박멸치료후 증상개선에 대한 메타분석)

  • Ohm, Sang-Hwa;Jeong, Ki-Won;Shin, Won-Chang;Cho, Jong-Rae;Shon, Hye-Suk;Pae, Ki-Taek;Kim, Sung-Jun
    • Journal of Preventive Medicine and Public Health
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    • v.32 no.4
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    • pp.427-434
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    • 1999
  • Objectives: This study was conducted to determine, by reviewing the literature, whether treatment of Helicobacter pylori infection in patients with non-ulcer dyspepsia affects symptoms. Methods: We retrieved the literature using MEDLINE search, with nonulcer dyspepsia and Hericobacter pylori and treatment as key words, which were reported from 1984 to 1998, and manual literature search. The criteria for inclusion was as follows; 1) The paper should have confirmed nonulcer dyspepsia as case definition. 2) The paper should have peformed a randomized, blind trial. 3) Confirmation of Helicobacter pylori eradication should be done 4 weeks after treatment. 4) studies with no information on measurement of symptoms after treatment were not accepted. The percentage of patients with symptom improvement after eradication therapy for Helicobacter pylori infection was calculated. Cumulative odds ratio was compared by fixed effect model and random effect model as sensitivity and funnel plot was used to evaluate publication bias. Results: The overall effect size of symptom improvement was calculated by cumulative odds ratio. Cumulative odds ratio of random effect model was 4.16(95% CI: 1.55-11.19). Before integrating each effect sizes into common effect size, the homogeneity test was conducted and random effect model was selected(Cochran's Q=41.08 (d.f=10, p<0.001)). The heterogeneity across studies was evaluated and the different methodological aspects of studies led to differences between study results Conclusions: The results suggest that the eradication of Helicobacter pylori in patients with non-ulcer dyspepsia results more symptom improvement. In studios that shows the opposite results there are methodological aspects explaining the heterogeneity.

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Evaluation of the MTHFR C677T Polymorphism as a Risk Factor for Colorectal Cancer in Asian Populations

  • Rai, Vandana
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.18
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    • pp.8093-8100
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    • 2016
  • Background: Genetic and environmental factors play important roles in pathogenesis of digestive tract cancers like those in the esophagus, stomach and colorectum. Folate deficiency and methylenetetrahydrofolate reductase (MTHFR) as an important enzyme of folate and methionine metabolism are considered crucial for DNA synthesis and methylation. MTHFR variants may cause genomic hypomethylation, which may lead to the development of cancer, and MTHFR gene polymorphisms (especially C677T and A1298C) are known to influence predispositions for cancer development. Several case control association studies of MTHFR C677T polymorphisms and colorectal cancer (CRC) have been reported in different populations with contrasting results, possibly reflecting inadequate statistical power. Aim: The present meta-analysis was conducted to investigate the association between the C677T polymorphism and the risk of colorectal cancer. Materials and Methods: A literature search of the PubMed, Google Scholar, Springer link and Elsevier databases was carried out for potential relevant articles. Pooled odds ratio (OR) with corresponding 95 % confidence interval (95 % CI) was calculated to assess the association of MTHFR C677T with the susceptibility to CRC. Cochran's Q statistic and the inconsistency index (I2) were used to check study heterogeneity. Egger's test and funnel plots were applied to assess publication bias. All statistical analyses were conducted by with MetaAnalyst and MIX version 1.7. Results: Thirty four case-control studies involving a total of 9,143 cases and 11,357 controls were retrieved according to the inclusion criteria. Overall, no significant association was found between the MTHFR C677T polymorphism and colorectal cancer in Asian populations (for T vs. C: OR=1.03; 95% CI= 0.92-1.5; p= 0.64; for TT vs CC: OR=0.88; 95%CI= 0.74-1.04; p= 0.04; for CT vs. CC: OR = 1.02; 95%CI= 0.93-1.12; p=0.59; for TT+ CT vs. CC: OR=1.07; 95%CI= 0.94-1.22; p=0.87). Conclusions: Evidence from the current meta-analysis indicated that the C677T polymorphism is not associated with CRC risk in Asian populations. Further investigations are needed to offer better insight into any role of this polymorphism in colorectal carcinogenesis.

Risk Factors of Breast Cancer in the Eastern Mediterranean Region: A Systematic Review and Meta-Analysis

  • Namiranian, Nasim;Moradi-Lakeh, Maziar;Razavi-Ratki, Seid Kazem;Doayie, Mahdyie;Nojomi, Marzieh
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.21
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    • pp.9535-9541
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    • 2014
  • Background: Identifying risk factors of breast cancer is a key point for preventive strategies to reduce the incidence. The aim of current study was to determine most important risk factors for breast cancer in the Eastern Mediterranean Region (EMR) using a systematic review. Materials and Methods: PubMed, Scopus, Web of Science till August 24, 2012 and the reference lists of all included studies were searched. Analytic studies which had reported odds ratios (OR), relative risk (RR) or required data to calculate them were included. A total of 343 studies were critically appraised and finally 30 studies were meta-analyzed. Heterogeneity between the studies was assessed by $I^2$ and Cochran's Q. Egger's test was used to assess publication bias. Results: Twenty five casecontrol studies, one nested case-control and four cohort studies were included. The largest ORs were obtained for history of no live birth (2.25; 95%CI: 1.58-3.18), body mass index (BMI) more than 30 (2.21; 95%CI: 1.71-2.36), age at first pregnancy more than 30 years old (1.52; 95%CI: 1.30-1.77) and meat consumption more than three times per week (1.39; 95%CI: 1.03-1.87). The other important predictors were higher education and smoking as risk factors, physical activity and ovulatory stimulating medication as protective factors. Conclusions: The most important predictors of breast cancer in EMR were history of no live birth, BMI more than 30, age at first pregnancy more than 30 years old, physical inactivity and smoking. Almost all these risk factors are consistent with known risk factors for this cancer in other parts of the world.

Estimate of the Basic Reproduction Number for COVID-19: A Systematic Review and Meta-analysis

  • Alimohamadi, Yousef;Taghdir, Maryam;Sepandi, Mojtaba
    • Journal of Preventive Medicine and Public Health
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    • v.53 no.3
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    • pp.151-157
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    • 2020
  • Objectives: The outbreak of coronavirus disease 2019 (COVID-19) is one of the main public health challenges currently facing the world. Because of its high transmissibility, COVID-19 has already caused extensive morbidity and mortality in many countries throughout the world. An accurate estimation of the basic reproduction number (R0) of COVID-19 would be beneficial for prevention programs. In light of discrepancies in original research on this issue, this systematic review and meta-analysis aimed to estimate the pooled R0 for COVID-19 in the current outbreak. Methods: International databases (including Google Scholar, Science Direct, PubMed, and Scopus) were searched to identify studies conducted regarding the R0 of COVID-19. Articles were searched using the following keywords: "COVID-19" and "basic reproduction number" or "R0." The heterogeneity among studies was assessed using the I2 index, the Cochran Q test, and T2. A random-effects model was used to estimate R0 in this study. Results: The mean reported R0 in the identified articles was 3.38±1.40, with a range of 1.90 to 6.49. According to the results of the random-effects model, the pooled R0 for COVID-19 was estimated as 3.32 (95% confidence interval, 2.81 to 3.82). According to the results of the meta-regression analysis, the type of model used to estimate R0 did not have a significant effect on heterogeneity among studies (p=0.81). Conclusions: Considering the estimated R0 for COVID-19, reducing the number of contacts within the population is a necessary step to control the epidemic. The estimated overall R0 was higher than the World Health Organization estimate.