• Title/Summary/Keyword: Confounding

검색결과 426건 처리시간 0.034초

한국 성인의 천식과 치아우식과의 관련성:제 6기 국민건강영양조사 자료 이용 (Relationship between asthma and dental caries in Korean adults: Data from the Sixth Korea National Health and Nutrition Examination Survey)

  • 최윤영
    • 한국치위생학회지
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    • 제19권1호
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    • pp.131-140
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    • 2019
  • Objectives: The purpose of this study was to evaluate the association between asthma and dental caries by using data from the Korean National Health and Nutrition Examination Survey (KNHANES), from 2013 to 2015. Methods: The study included 11,731 subjects who were ${\geq}19$ years of age and analyzed their demographic-, socioeconomic-, health-, and oral health care-related data. The chi-squared test and logistic regression analysis were conducted using complex sample analyses to examine the relationship between asthma and dental caries. Results: Compared with the control group, the risk for dental caries in the asthma group was 1.207 times higher, regardless of various confounding factors (p<0.001). In the asthma group, the mean DMFT score was significantly higher than that in the control group (p<0.001). After adjusting for confounding factors, the mean number of DMFT in subjects with asthma was 7.67, which was higher than that in subjects without asthma (7.28) (p<0.001). Conclusions: The study results show that asthma may be a risk factor for dental caries. Therefore, in order to prevent dental caries in asthma patients, oral hygiene education is important.

우리나라 노인의 성별에 따른 우울 증상과 미충족 치과 치료의 관련성: 제7기 국민건강영양조사 자료 활용 (Relationship between depressive symptoms and unmet dental treatment according to gender of the elderly in Korea: 7th National Health and Nutrition Survey)

  • 전영은;이가은;황진섭;정윤숙
    • 한국치위생학회지
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    • 제22권6호
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    • pp.503-512
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    • 2022
  • Objectives: This study aimed to study the association between unmet dental treatment and depression in the dental area of the elderly. Methods: The data was from the 7th period of the National Health and Nutrition Examination Survey. Multiple logistic regression analysis was performed to evaluate the relationship between depression and unmet dental treatment when confounding factors such as income quintile and smoking were considered. Statistical software, SAS 9.4 version was used. Results: After correcting all confounding factors, the analysis showed that the experience of unmet dental treatment was 2.73 times more likely among depressed men and 2.52 times more likely among depressed women (p<0.05). Conclusions: The results of this study suggested that we should consider that depression in the elderly can affect unmet dental treatment regardless of gender.

혼합물실험(混合物實驗)의 공정변수(工程變數)에 관한 교락(交絡) block 효과(效果) (Block Confounding Effect for Mixture Experiments with Process Variables)

  • 정중희;김정만
    • 품질경영학회지
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    • 제13권2호
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    • pp.66-72
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    • 1985
  • The objective of mixture experiments with process variables is to find experimental blends and conditions that produce the product of highest quality. In this paper, designs for mixture experiments with process variables are presented, where the emphasis is on using only a fraction of the total number of possible design points and the fitting of reduced models for measuring the effects of the mixture components and process variables.

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Confounded Row-Column Designs

  • Choi Kuey Chung;Gupta Sudhir
    • 한국통계학회:학술대회논문집
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    • 한국통계학회 2004년도 학술발표논문집
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    • pp.313-317
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    • 2004
  • Confounded row-column designs for factorial experiments are studied in this paper. The Designs, thus, have factorial balance with respect to estimable main effects and interactions. John and Lewis (1983) considered generalized cycle row=column designs for factorial experiments. A simple method of constructing confounded designs using the classical method of confounding for block designs is described in this paper

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A study On An Identification of Interactions In A Nonreplicated Two-Way Layout With $L_1$-Estimation

  • Lee, Ki-Hoon
    • Communications for Statistical Applications and Methods
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    • 제7권1호
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    • pp.119-128
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    • 2000
  • This paper proposes a method for detecting interactions in a two-way layout with one observation per cell. The identification of interactions in the model is not clear for they are confounding with error terms. The $L_1$-Estimation is robust with respect to a y-direction outlier in linear model so we are able to estimate main effects without affection of interactions, If an observation is classified as an outlier we conclude it contains an interaction. An empirical study compared with a classical method is performed.

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Association between periodontal flap surgery for periodontitis and vasculogenic erectile dysfunction in Koreans

  • Lee, Jae-Hong;Choi, Jung-Kyu;Kim, Sang-Hyun;Cho, Kyung-Hyun;Kim, Young-Taek;Choi, Seong-Ho;Jung, Ui-Won
    • Journal of Periodontal and Implant Science
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    • 제47권2호
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    • pp.96-105
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    • 2017
  • Purpose: The National Health Insurance Service-National Sample Cohort and medical checkup data from 2002 to 2013 were used to evaluate the association between periodontal surgery for the treatment of periodontitis (PSTP) and vasculogenic erectile dysfunction (VED). Methods: Bivariate and multivariate logistic regression analyses were applied to a longitudinal retrospective database to assess the association between PSTP and VED while adjusting for the potential confounding effects of sociodemographic factors (age, household income, insurance status, health status, residence area, and smoking status) and comorbidities (diabetes mellitus, angina pectoris, cerebral infarction, and myocardial infarction). Results: Among the 7,148 PSTP within the 268,296 recruited subjects, the overall prevalence of VED in PSTP was 1.43% (n=102). The bivariate analysis showed that VED was significantly related to PSTP (odds ratio [OR], 1.99; 95% confidence interval [CI], 1.38-2.06; P<0.001), and this was confirmed in the multivariate analysis after adjusting for sociodemographic factors and comorbidities (OR, 1.29; 95% CI, 1.06-1.58; P=0.002). Conclusions: Subjects with a history of periodontal flap surgery had a significantly higher risk of VED, after adjusting for potential confounding factors. Further studies are required to identify the key mechanisms underlying the association between severe periodontal disease and VED.

Benzene and Leukemia: The 0.1 ppm ACGIH Proposed Threshold Limit Value for Benzene

  • Infante Peter F.
    • 대한예방의학회:학술대회논문집
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    • 대한예방의학회 1994년도 교수 연수회(환경)
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    • pp.681-691
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    • 1994
  • The American Conference of Governmental Industrial Hygienists (ACGIH) has proposed a threshold limit value (TLV) for benzene of 0.1 ppm. Individuals representing the American Petroleum Institute (API)and the Chemical Manufacturers Association (CMA) have argued that 1) the risk assessment by Rinsky .et al. which ACGIH partially relied upon for its proposed TLV overestimates the risk; however, at the exposures levels of interest - (e.g., 0.1 to 1.0 ppm) for establishing a benzene TLV, the Rinsky et al. assessment provides lower estimates of leukemia risk than most others; 2) ACGIH should not use the Dow study for direct observational evidence of leukemia risk associated with low-level benzene exposure because of confounding exposure; however, it is unlikely that confounding exposures played a role in the excess of leukemia demonstrated in the study, and the Dow cohort was exposed to an average benzene concentration of about 5.5 ppm benzene for 7.11 years (31:1.5 ppm-years), while some of the individuals in the study who died from leukemia were exposed to an average of only 1.0 ppm without the opportunity for highpeak exposures; 3) the Occupational Safety and Health Administration (OSHA) established an 8-hour time-weighted average (TWA) of 1.0 ppm in 1987, and there is no new evidence that would justify reducing the TWA below that level; however, the OSHA TWA of 1.0 ppm was based on economic feasibility and the level of excess risk remaining at 1.0 ppm, i.e., 10 excess leukemia deaths per 1000 workers over an occupational lifetime (45 years) according to OSHA's preferred estimate leaves behind I risk considered significant by OSHA. In addition, chromosomal studies among workers and in animals exposed to benzene indicate that low-level exposure, i.e., 1.0 ppm, is associated with elevated Cytogenetic damage. On the basis of adverse health effects data alone, in this author's opinion, it would be poor science and poor public health policy to establish a benzene TLV greater than 0.1 ppm.

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청소년의 간식 종류별 섭취빈도와 과체중 및 비만 위험률과의 연관성 분석 - 2007~2009 국민건강영양조사 자료를 바탕으로 - (Association between Consumption Frequency of Each Kind of Snack and Risk of Overweight and Obesity in Adolescents - From the Korean National Health and Nutrition Examination Surveys, 2007~2009 -)

  • 연지영
    • 한국식품영양학회지
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    • 제30권1호
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    • pp.74-82
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    • 2017
  • This study was conducted to evaluate the risk of overweight and obesity in adolescents consuming snacks frequently from 2007~2009, Korean National Health and Nutrition Examination Survey (KNHANES). The subjects (12~14 years: n=523; 15~18 years: n=614) were presented with food frequency questionnaires, and they were classified according to their gender and frequency of snack consumption. In the age group of 12~14 years, boys and girls (boys OR: 1.11, 95% CI: 0.52~2.39, girls OR: 12.45, 95% CI: 2.26~68.51) who consumed yogurt frequently had a higher risk of overweight and obesity at the highest quartile frequency compared with the lowest quartile after adjustments for multiple confounding factors, including age, physical activity, frequency of eating out and snack consumption, and energy intake. In the age group of 15~18 years, girls (OR: 1.01, 95% CI: 0.34~2.99) consuming fried foods had a higher risk of overweight and obesity at the highest quartile frequency compared with the lowest quartile after adjustments for multiple confounding factors, including age, physical activity, frequency of eating out and snack consumption, and energy intake. Thus, we conclude that frequent consumption of yogurt and fried foods increases the risk of overweight and obesity in adolescents. These findings suggest that the risk of overweight and obesity is associated with the frequency of snack consumption.

여성의 모유수유 기간 및 임신 횟수와 치주염의 연관성에 대한 융합연구 (A Convergence Study of association between breastfeeding and pregnancy and periodontitis in Women)

  • 이세영;박정란;심선주
    • 한국융합학회논문지
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    • 제9권10호
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    • pp.149-157
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    • 2018
  • 본 연구는 성인여성에서 임신관련 건강요인과 치주염과의 상관성을 연구하기 위해 2010-2014년 국민건강영양조사자료를 활용하여 분석하였다. 종속변수는 치주염이었으며 독립변수는 임신관련 건강요인으로서 출산후 수유기간과 임신횟수를 분석하였으며, 사회경제학적변수 및 건강관련행위는 혼란변수로 보정하였다. 임신횟수와 치주염은 여러 혼란요인을 보정한 후에 상관성이 높았다[임신횟수 2-3번인 여성의 교차비: 2.66(95% 신뢰구간: 1.56-4.54); 임신횟수 4회 이상인 여성의 교차비: 3.02(95% 신뢰구간: 1.70-5.36)]. 결론적으로 치주염은 임신횟수와 밀접하게 연관되어 있으며 향후 임산부 구강보건교육 및 여성을 대상으로 하는 구강보건교육 프로그램을 개발함에 있어서 기초자료로 활용하고자 한다.