• Title/Summary/Keyword: fixed bias

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The Effects of Long-term Care Insurance on the Life Satisfaction and Satisfaction in Family Relationships - The DD Method Combined with Propensity Score Matching - (노인장기요양보험제도가 대상노인 및 부양가족의 삶의 질과 가족관계 만족도에 미치는 영향 - 성향점수매칭(PSM)과 이중차이(DD) 결합모형을 이용한 분석 -)

  • Kwon, Hyun-Jung;Cho, Yong-Un;Ko, Ji-Young
    • Korean Journal of Social Welfare
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    • v.63 no.4
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    • pp.301-326
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    • 2011
  • The major purpose of this study is to evaluate the impact of the long-term care insurance program. In order to estimate the impact of policy accurately, certain bias which might hamper the validity of this study has been removed by Propensity Score Matching(PSM) and Double Difference(DD) method from the semi-experimental design. To study the effects of long-term care insurance on the elderly and their family members as social outcome variable sand the quality of life of their family and satisfaction in family relationships, the third and fourth waves of Korea Welfare Panel are used to match experimental and comparative groups by the propensity score matching. Then, DD method, using the panel fixed effects model, is applied to estimate the differences of those groups'treatment effects before and after the policy implementation. As a result, it was found that the Quality of life on the elderly and their family members is statistically meaningless, while the satisfaction in family relationships has much increased after the policy implementation. The result has a limitation in that this evaluation is performed at the point when the long-term insurance program has not been ripened enough. However, there is an important implication on the significance of realizing the main goal of the long-term care insurance to improve the quality of life of the elderly and their family members and as for the potentiality of further system improvements.

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Association between Pax8-PPARγ1 Rearrangement and Follicular Thyroid Cancer: a Meta-Analysis

  • Li, Hang-Yu;Xie, Zhi-Hao;Xu, Cong-Hui;Pu, Mei-Ling;Chen, Zi-Yan;Yu, Miao;Wang, Heng-Shu;Zhou, Chen-Ming;Pu, Chao-Yu;Liu, Wei
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.9
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    • pp.4247-4250
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    • 2016
  • Background: Pax8 and peroxisome proliferator-activated receptor gamma 1 gene (Pax8-$PPAR{\gamma}1$) are important factors in tumors. Several studies have suggested that follicular thyroid cancer may arise from Pax8- $PPAR{\gamma}1$ rearrangement. In order to have a better understanding of the association between Pax8-$PPAR{\gamma}1$ rearrangement and follicular thyroid cancer, we conducted the presenmt meta-analysis. Materials and Methods: The information was extracted from PubMed, EMBASE and Web of Science. Statistic analysis was performed with Stata12.0 software. Odds ratios (ORs) were calculated using a fixed-effects model. We also performed heterogeneity and publication bias analyses. Results: Nine studies including 198 follicular thyroid cancer patients and 268 controls were considered eligible. The frequency of Pax8-$PPAR{\gamma}1$ rearrangement was significantly higher in the follicular thyroid cancer group than in the control group, with a pooled OR of 6.63 (95%CI=3.50-12.7). In addition, through subgroup analysis, the OR between Pax8-$PPAR{\gamma}1$ rearrangement and follicular thyroid cancer was 6.04 (95%CI = 3.18-11.5) when using benign tumor tissues as controls. The OR for the method subgroup was 9.99 (95% CI =4.86-20.5) in the RT-PCR. Conclusions: The final results demonstrated that Pax8-$PPAR{\gamma}1$ rearrangement has significant association with follicular thyroid cancer.

Methodologic Lessons Learned from Multicenter, Randomized, Controlled Clinical Trial of Acupuncture for Hot Flashes in Peri- and Postmenopausal Women (갱년 및 폐경 후 여성의 안면홍조에 대한 침 치료 다기관 임상연구 : 수행보고 및 방법론적 교훈)

  • Kim, Kun-Hyung;Kim, Dong-Il;Hwang, Deok-Sang;Lee, Jin-Moo;Kim, Hyung-Jun;Yoon, Hyun-Min;Jung, Hee-Jung;Kang, Kyung-Won;Lee, Myeong-Soo;Choi, Sun-Mi
    • The Journal of Korean Obstetrics and Gynecology
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    • v.23 no.1
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    • pp.42-52
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    • 2010
  • Purpose: This report aims to administer methodologic issues around recently conducted multicenter study for evaluating the effects of acupuncture on menopusal hot flashes and discuss practical issues for further implementation of acupuncture clinical trial for hot flashes. Methods: Study process were mentioned, and issues related to avoiding risk of bias, designing appropriate control group, optimal outcome measurement, potential different effects of menopausal status on study outcomes, and suggestions for developing future clinical trials are discussed. Results: Shortcomings of our multicenter study include lack of allocation concealment and assessor blinding, subjective outcome measurement, short-term follow-up, and fixed acupuncture regimen despite pragmatic purpose of this study. Improving trial design, using objective or validated outcomes, assessing long-term effects of acupuncture, and individualizing acupuncture regimen are needed in future clinical trials. Conclusion: We expect these practical discussions to enable researchers to plan and develop future well-designed clinical trials for evaluating the effects of acupuncture on hot flashes or other women's health issues.

Vegetable Oil Intake and Breast Cancer Risk: a Meta-analysis

  • Xin, Yue;Li, Xiao-Yu;Sun, Shi-Ran;Wang, Li-Xia;Huang, Tao
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.12
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    • pp.5125-5135
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    • 2015
  • Background: Total fat intake may be associated with increased risk of breast cancer, and fish oil has been suggested as a protection factor to breast cancer. But the effect of vegetable oils is inconclusive. We aimed to investigate the association with high vegetable oils consumption and breast cancer risk, and evaluated their dose-response relationship. Design: We systematically searched the MEDLINE, EMBASE, Cochrane databases, and CNKI updated to December 2014, and identified all observational studies providing quantitative estimates between breast cancer risk and different vegetable oils consumption. Fixed or random effect models were used to estimate summary odds ratios for the highest vs. lowest intake, and dose-response relationship was assessed by restricted cubic spline model and generalized least-squares trend (GLST) model. Results: Five prospective cohort studies and 11 retrospective case-control studies, involving 11,161 breast cancer events from more than 150,000 females, met the inclusion criteria. Compared with the lowest vegetable oils consumption, higher intake didn't increased the risk of breast cancer with pooled OR of 0.88 (95% CIs:0.77-1.01), and the result from dose-response analyses didn't show a significant positive or negative trend on the breast cancer risk for each 10g vegetable oil/day increment (OR=0.98, 95% CIs: 0.95-1.01). In the subgroup analyses, the oils might impact on females with different strata of BMI. Higher olive oil intake showed a protective effect against breast cancer with OR of 0.74 (95% CIs: 0.60-0.92), which was not significant among the three cohort studies. Conclusions: This meta-analyses suggested that higher intake of vegetable oils is not associated with the higher risk of breast cancer. Olive oil might be a protective factor for the cancer occurrence among case-control studies and from the whole. Recall bias and imbalance in study location and vegetable oils subtypes shouldn't be ignored. More prospective cohort studies are required to confirm the interaction of the impact of vegetable oils on different population and various cancer characteristic, and further investigate the relationship between different subtype oils and breast cancer.

Lack of Any Association of GST Genetic Polymorphisms with Susceptibility to Ovarian Cancer - a Meta-analysis

  • Han, Li-Yuan;Liu, Kui;Lin, Xia-Lu;Zou, Bao-Bo;Zhao, Jin-Shun
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.15
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    • pp.6131-6136
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    • 2014
  • Objective: Epidemiology studies have reported conflicting results between glutathione S-transferase Mu-1 (GSTM1), glutathione S-transferase theta-1 (GSTT1) and glutathione S-transferase pi-1 (GSTP1) and ovarian cancer (OC) susceptibility. In this study, an updated meta-analysis was applied to determine whether the deletion of GSTM1, GSTT1 and GSTP1 has an influence on OC susceptibility. Methods: A published literature search was performed through PubMed, Embase, Cochrane Library, and Science Citation Index Expanded database for articles published in English. Pooled odds ratios (ORs) and 95% confidence intervals (95%CIs) were calculated using random or fixed effects models. Heterogeneity between studies was assessed using the Cochrane Q test and $I^2$ statistics. Sub-group analysis was conducted to explore the sources of heterogeneity. Sensitivity analysis was employed to evaluate the respective influence of each study on the overall estimate. Results: In total, 10 published studies were included in the final analysis. The combined analysis revealed that there was no significant association between GSTM1 null genotype and OC risk (OR=1.01, 95%CI: 0.91-1.12). Additionally, there was no significant association between GSTT1 genetic polymorphisms and OC risk (OR=0.98, 95% CI: 0.85-1.13). Similalry, no significant associations were found concerning the GSTP1 rs1695 locus and OC risk. Meanwhile, subgroup analysis did not show a significant increase in eligible studies with low heterogeneity. However, sensitivity analysis, publication bias and cumulative analysis demonstrated the reliability and stability of the current meta-analysis. Conclusions: These findings suggest that GSTs genetic polymorphisms may not contribute to OC susceptibility. Large epidemiological studies with the combination of GSTM1 null, GSTT1 null and GSTP1 Ile105Val polymorphisms and more specific histological subtypes of OC are needed to prove our findings.

The XRCC1 Arg399Gln Genetic Polymorphism Contributes to Hepatocellular Carcinoma Susceptibility: An Updated Meta-analysis

  • Pan, Yan;Zhao, Lei;Chen, Xing-Miao;Gu, Yong;Shen, Jian-Gang;Liu, Lu-Ming
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.10
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    • pp.5761-5767
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    • 2013
  • The potential correlation of X-ray repair cross-complementing group 1 (XRCC1) Arg399Gln polymorphism with hepatocellular carcinoma (HCC) susceptibility is ambiguous. Taking account of inconsistent results of previous meta-analyses and new emerging literatures, we conducted a meta-analysis covering 15 case-control datasets to evaluate the relationship. Relevant studies from Medline, Embase and CNKI were retrieved. A fixed-effect model or a random-effect model, depending on between-study heterogeneity, were applied to estimate the association between XRCC1 polymorphism Arg399Gln and HCC risk with the results presented as odds ratios (ORs) and 95% confidence intervals (95% CIs). In accordance with Hardy-Weinberg equilibrium, 15 studies with data for 6,556 individuals were enrolled in this systematic review. For overall HCC,thr XRCC1 polymorphism Arg399Gln was significantly associated with HCC susceptibility in a homozygote model as well as in a dominant model (G/G vs. A/A, OR=1.253, p=0.028; G/G+A/G vs. A/A, OR= 1.281, p=0.047, respectively), but not in a heterozygote model (A/G vs. A/A, OR=1.271, p=0.066) or a recessive model (G/G vs. A/G + A/A, OR= 1.049, p=0.542). Similar results were also observed on stratification analysis by ethnicity (A/G vs. A/A, OR=1.357, p=0.025; G/G vs. A/A, OR=1.310, p=0.011; G/G+A/G vs. A/A, OR= 1.371, p=0.013). However, no potential contribution of XRCC1 Arg399Gln polymorphism to HCC susceptibility in HBV/HCV subgroups was identified. No publication bias was found in this study. In conclusion, the XRCC1 Arg399Gln polymorphism contributes to HCC susceptibility. Due to the lack of studies in Western countries, further large-sample and rigorous studies are needed to validate the findings.

XRCC1 Gene Polymorphisms and Breast Cancer Risk: A Systematic Review and Meta-analysis Study

  • Moghaddam, Ali Sanjari;Nazarzadeh, Milad;Moghaddam, Hossein Sanjari;Bidel, Zeinab;Karamatinia, Aliasghar;Darvish, Hossein;Jarrahi, Alireza Mosavi
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.sup3
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    • pp.323-335
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    • 2016
  • Breast cancer risk assessment has developed during years and evaluation of genetic factor affecting risk of breast cancer is an important component of this risk assessment. The aim of this meta-analysis was to investigate the role of XRCC1 polymorphisms (Arg194Trp, Arg280His and Arg399Gln) in risk of breast cancer among different population and categories of menopausal status.PubMed, Medline, Web of Science, and PubMed Central were systematically searched to identify studies evaluating association between breast cancer and XRCC1 gene polymorphisms (Arg194Trp, Arg280His and Arg399Gln). Two authors independently extracted required information. Odds Ratios were pooled for four genetic inheritance models using both fixed and the DerSimonian and Laird random-effect models. Egger's test and contour-enhanced funnel plot was used to evaluate publication bias and small study effect. Additional subgroup analysis was performed for menopausal status, ethnicity, and source of controls. After evaluation and applying inclusion criteria on extracted studies, fifty three studies were included in this meta-analysis. For polymorphisms of Arg194Trp and Arg280His, no significant association was observed in all genetic models. Arg194Trp had a protective effect in post-menopausal status only in homozygote model (OR=0.57 [0.37-0.88]). Arg399Gln showed significant association with breast cancer in homozygote (OR=1.21 [1.10-1.34]), dominant (OR=1.09 [1.03-1.15]) and recessive (OR=1.21 [1.09- 1.35]) genetic models. Arg399Gln was associated with higher risk in post-menopausal status for homozygote and heterozygote models. Our findings suggest that XRCC1 gene polymorphisms modify breast cancer risk in different populations and different categories of menopausal status.

Simulation of Agricultural Water Supply Considering Yearly Variation of Irrigation Efficiency (연단위 관개효율 변화를 고려한 관개지구 용수 공급량 모의)

  • Song, Jung Hun;Song, Inhong;Kim, Jin Taek;Kang, Moon Seong
    • Journal of Korea Water Resources Association
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    • v.48 no.6
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    • pp.425-438
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    • 2015
  • The objective of this study was to evaluate simulation of agricultural water supply considering yearly variation of irrigation efficiency. The water supply data of the Idong reservoir from 2001 through 2009 was collected and used for this study. Total 6 parameters including irrigation efficiency (Es), drainage outlet height, and infiltration, were used for sensitivity analysis, calibration, and validation. Among the parameters, the Es appeared to be the most sensitivity parameter. The Es was calibrated on a yearly basis considering sensitivity and time-varying characteristic, while other parameters were set to fixed values. The statistics of percent bias (PBLAS), Nash-Sutcliffe efficiency (NSE), and root means square error to the standard deviation of measured data (RSR) for a monthly step were 2.7%, 0.93, and 0.26 for the calibration, and 3.9%, 0.89, and 0.32 for the validation, correspondently. The results showed a good agreement with the observations. This implies that the modeling only with appropriate parameter values, apart from modeling approaches, can simulate the real supply operation reasonably well. However, the simulations with uncalibrated parameters from previous studies produced poor results. Thus, it is important to use calibrated values, and especially, we suggest the Es's yearly calibration for simulating agricultural water supply.

Systematic Review of Short Stature and Growth Related Qualitative Researches (저신장 및 성장과 관련된 질적연구에 대한 체계적 문헌 고찰)

  • Kim, Hye Jin;Jeon, Chae Heun;Roh, Min Yeong;Han, Ye Ji;Kim, Hyun Ho;Cheong, Moon Joo;Leem, Jung Tae
    • The Journal of Pediatrics of Korean Medicine
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    • v.33 no.4
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    • pp.74-88
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    • 2019
  • Objectives The aim of this study is systematic evaluation of the quality of qualitative studies related to short stature. It will be utilized as fundamental data for future qualitative research about Korean Medicine Pediatrics treatment for short stature. Methods We searched qualitative studies related to short stature in the Pubmed. Two researchers independently assessed the quality of the qualitative researches by using Consolidated criteria for reporting qualitative research (COREQ) and Critical Appraisal Skills Program (CASP). We also qualitatively synthesized theme of each included studies. We presented integrated theme and categories with in vivo coding about qualitative research about short stature. Results A total of 47 papers were screened and 7 papers were finally selected. In the quality assessment using COREQ, detalied information about the researchers, methods of approach, reasons for non-participation, presence of non-participants, participant's review of the transcript, and participant's review of the findings were insufficient. In the quality evaluation using CASP, there were lack of justifications for the research methods, description method of research, and bias in process of data analysis. The findings were synthesized into three themes: fixed idea about height, discomfort caused by small stature and personal coping strategy with stress caused by short stature. Conclusions In further qualitative research, it is necessary to report the research according to COREQ and CASP checklist. It is also necessary to understand the stress and coping strategies to short stature of patients, We need to develop a social management strategy for short stature.

Estimation of reflectivity-rainfall relationship parameters and uncertainty assessment for high resolution rainfall information (고해상도 강수정보 생산을 위한 레이더 반사도-강수량 관계식 매개변수 보정 및 불확실성 평가)

  • Kim, Tae-Jeong;Kim, Jang-Gyeong;Kim, Jin-Guk;Kwon, Hyun-Han
    • Journal of Korea Water Resources Association
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    • v.54 no.5
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    • pp.321-334
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    • 2021
  • A fixed reflectivity-rainfall relationship approach, such as the Marshall-Palmer relationship, for an entire year and different seasons, can be problematic in cases where the relationship varies spatially and temporally throughout a region. From this perspective, this study explores the use of long-term radar reflectivity for South Korea to obtain a nationwide calibrated Z-R relationship and the associated uncertainties within a Bayesian inference framework. A calibrated spatially structured pattern in the parameters exists, particularly for the wet season and parameter for the dry season. A pronounced region of high values during the wet and dry seasons may be partially associated with storm movements in that season. Overall, the radar rainfall fields based on the proposed modeling procedure are similar to the observed rainfall fields. In contrast, the radar rainfall fields obtained from the existing Marshall-Palmer relationship show a systematic underestimation. In the event of high impact weather, it is expected that the value of national radar resources can be improved by establishing an active watershed-level hydrological analysis system.