• 제목/요약/키워드: confounding factors

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Risk Factors for Delayed Hinge Fracture after Plate-Augmented Cervical Open-Door Laminoplasty

  • Hur, Junseok W.;Park, Youn-Kwan;Kim, Bum-Joon;Moon, Hong-Joo;Kim, Joo-Han
    • Journal of Korean Neurosurgical Society
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    • 제59권4호
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    • pp.368-373
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    • 2016
  • Objective : Delayed hinge fracture (HF) that develops after cervical open door laminoplasty can be a source of postoperative complications such as axial pain. However, risk factors related to this complication remain unclear. We performed a retrospective clinical series to determine risk factors for delayed HF following plate-only open-door cervical laminoplasty. Methods : Patients who underwent plate-only open-door laminoplasty and had available postoperative computed tomography (CT) scans (80 patients with 270 laminae) were enrolled. Hinge status, hinge gutter location, open location, hinge width, number of screws used, operation level, and open angle were observed in the CT to determine radiographic outcome. Demographic data were collected as well. Radiographic and clinical parameters were analyzed using univariate and multivariate logistic regression analysis to determine the risk factors for HF. Results : Univariate logistic regression analysis results indicated poor initial hinge status, medially placed hinge gutter, double screw fixation on the elevated lamina, upper surgical level, and wide open angle as predictors for HF (p<0.05). Initial hinge status seemed to be the most powerful risk factor for HF (p=0.000) and thus was collinear with other variables. Therefore, multivariate logistic regression analysis was performed excluding initial hinge status, and the results indicated that medially placed hinge gutter, double screw fixation on the elevated lamina, and upper surgical level were risk factors for HF after adjustment for other confounding factors. Conclusion : To prevent HF and to draw a successful postoperative outcome after cervical laminoplasty, surgical and clinical precautions should be considered.

Did the Timing of State Mandated Lockdown Affect the Spread of COVID-19 Infection? A County-level Ecological Study in the United States

  • Trivedi, Megh M.;Das, Anirudha
    • Journal of Preventive Medicine and Public Health
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    • 제54권4호
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    • pp.238-244
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    • 2021
  • Objectives: Previous pandemics have demonstrated that several demographic, geographic, and socioeconomic factors may play a role in increased infection risk. During this current coronavirus disease 2019 (COVID-19) pandemic, our aim was to examine the association of timing of lockdown at the county level and aforementioned risk factors with daily case rate (DCR) in the United States. Methods: A cross-sectional study using publicly available data was performed including Americans with COVID-19 infection as of May 24, 2020. The United States counties with >100 000 population and >50 cases per 100 000 people were included. The independent variable was the days required from the declaration of lockdown to reach the target case rate (50/100 000 cases) while the dependent (outcome) variable was the DCR per 100 000 on the day of statistical calculation (May 24, 2020) after adjusting for multiple confounding socio-demographic, geographic, and health-related factors. Each independent factor was correlated with outcome variables and assessed for collinearity with each other. Subsequently, all factors with significant association to the outcome variable were included in multiple linear regression models using stepwise method. Models with best R2 value from the multiple regression were chosen. Results: The timing of mandated lockdown order had the most significant association on the DCR per 100 000 after adjusting for multiple socio-demographic, geographic and health-related factors. Additional factors with significant association with increased DCR include rate of uninsured and unemployment. Conclusions: The timing of lockdown order was significantly associated with the spread of COVID-19 at the county level in the United States.

Measurements of fractional exhaled nitric oxide in pediatric asthma

  • Hahn, Youn-Soo
    • Clinical and Experimental Pediatrics
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    • 제56권10호
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    • pp.424-430
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    • 2013
  • Exhaled nitric oxide (NO) has been extensively investigated as a noninvasive marker of airway inflammation in asthma. The increased NO expression induced by inflammatory mediators in airways can be monitored easily in exhaled air from asthmatic children. Based on the relationship between the increased NO expression and eosinophilic airway inflammation, fractional exhaled nitric oxide (FeNO) measurements become an important adjunct for the evaluation of asthma. In addition, the availability of portable devices makes it possible to measure FeNO more easily and frequently in the routine pediatric practice. Despite various confounding factors affecting its levels, FeNO can be applicable in diagnosing asthma, monitoring treatment response, evaluating asthma control, and predicting asthma exacerbations. Thus, although pulmonary function tests are the standard tools for objective measurements of asthmatic control, FeNO can broaden the way of asthma monitoring and supplement standard clinical asthma care guidelines.

Improving Indentification Performance by Integrating Evidence From Evidence

  • Park, Kwang-Chae;Kim, Young-Geil;Cheong, Ha-Young
    • 한국정보전자통신기술학회논문지
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    • 제9권6호
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    • pp.546-552
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    • 2016
  • We present a quantitative evaluation of an algorithm for model-based face recognition. The algorithm actively learns how individual faces vary through video sequences, providing on-line suppression of confounding factors such as expression, lighting and pose. By actively decoupling sources of image variation, the algorithm provides a framework in which identity evidence can be integrated over a sequence. We demonstrate that face recognition can be considerably improved by the analysis of video sequences. The method presented is widely applicable in many multi-class interpretation problems.

Application of Standardization for Causal Inference in Observational Studies: A Step-by-step Tutorial for Analysis Using R Software

  • Lee, Sangwon;Lee, Woojoo
    • Journal of Preventive Medicine and Public Health
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    • 제55권2호
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    • pp.116-124
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    • 2022
  • Epidemiological studies typically examine the causal effect of exposure on a health outcome. Standardization is one of the most straightforward methods for estimating causal estimands. However, compared to inverse probability weighting, there is a lack of user-centric explanations for implementing standardization to estimate causal estimands. This paper explains the standardization method using basic R functions only and how it is linked to the R package stdReg, which can be used to implement the same procedure. We provide a step-by-step tutorial for estimating causal risk differences, causal risk ratios, and causal odds ratios based on standardization. We also discuss how to carry out subgroup analysis in detail.

Depressive Symptoms and Menstrual Cycle Irregularity among Community Women of Childbearing Age

  • Heeja Jung;Yanghee Pang
    • International Journal of Advanced Culture Technology
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    • 제11권2호
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    • pp.109-117
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    • 2023
  • Menstrual cycle irregularity reflects the reproductive health of women of childbearing age, but studies are scant on women in communities. In this study, we identified factors associated with menstrual cycle irregularity among 884 community women of childbearing age (19-40 years) and confirmed the relationship between menstrual cycle irregularity and depressive symptoms. Data were collected through online or mobile platforms. We noted that 25% of participants had menstrual cycle irregularity. Multivariable ordinal logistic regression analysis revealed that age, irregular eating, and depressive symptoms were associated with menstrual cycle irregularity. After adjusting for confounding variables, participants with depressive symptoms were at a slightly higher risk of menstrual cycle irregularity (odds ratio = 1.078, confidence interval = 1.021-1.139). Additional support be provided for community-living women of childbearing age with depressive symptoms, to improve their reproductive health

서울시 교직원 당뇨병의 역학적 특성 및 관련위험요인분석 (A Study of the Epidemiological Characteristics and Related Factors in School personnel with Diabetes Mellitus)

  • 이희우;김종희;장철환;신선미
    • 한국학교보건학회지
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    • 제17권1호
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    • pp.71-83
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    • 2004
  • Purpose: To describe the prevalence, epidemiological characteristics, and related factors of diabetes mellitus in school personnel. Method:5,384 school personnel (2,638 males 2,746 females) received physical examinations at the Seoul School Health Center in 2002. Using the American Diabetes Association criteria, and fasting blood sugar(FBS) was classified as normal at 110>=FBS, borderline 111-125, and the diabetes group 126<=FBS. Related factors of each group were evaluated by gender. Results: In the diabetes group, there were 4.74% males and 0.8% females, and the borderline group was 6.37% males and 2.22% females. The older age group gad a higher distribution in both males and females in the diabetes group. In the diabetes group, the mean and abnormal rate of BMI, systolic hypertension, diastolic hypertension, total cholesterol, GOT, GPT, and GTP were higher than in the normal group. In life style factor, the diabetes group gad a higher distribution of meat eating and smoking more than 20 years than the normal group. The effect of FBS on BMI, BP(blood pressure), total cholesterol, GOT, GPT, and GTP were investigated after controlling for confounding variables. In the borderline and diabetes group, the mean of BMI, BP, total cholesterol, GOT, GPT, and GTP was higher in dose-response effect. In the logistic multiple regression, the related factors of the diabetes group were hypertension and abnormal GTP in males, and abnormal total cholesterol and GTP in females. In the borderline group, the related factors were meat eating, hypertension, and high GOT in males and the older age group, and hypertension, total cholesterol, and abnormal GTP in females. Conclusions: It is possible to manage all related factors of diabetes mellitus except for age. An appropriate program for health promotion is necessary.

중장년층과 노년층의 건강관련 특성이 현존 자연치아수에 미치는 영향 (Effect of Health-Related Characteristics of Middle-Aged and Elderly People on the Number of Existing Permanent Teeth)

  • 이은주
    • 보건의료산업학회지
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    • 제10권3호
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    • pp.123-133
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    • 2016
  • Objectives : This study analyzed the effect of health-related characteristics of middle-aged and elderly people on the number of existing permanent teeth by considering each age group through the improvement of health-related characteristics. This study contributes by offering fundamental information on the prevention of dental diseases and on developing an education program that can be used by dental health businesses to improve dental health. Methods : This study used primitive data of the sixth term of the first year and the second year and selected a total of 4,393 people as the final research subject. In order to determine the factors that influence the number of existing natural teeth, confounding factors were considered, and regression analysis using general linear models was done. Results : According to the results of this research, the middle-aged and elderly groups have more existing permanent teeth in the following three cases: 1. Talking is comfortable when daily brushing frequency is 3 times or more. 2. Self-recognition of dental health condition is good. 3. Number of dental caries present in permanent teeth is low. Conclusions : For a and medical system, a dental health care system that takes into consideration the lifespans of people must be legislated and implemented.

Risk Assessment of Breast Cancer in Guangdong, China: A Community-based Survey

  • Lin, Ying;Shao, Nan;Zhang, Yun-Jian;Wu, Zhuang-Hong;Li, Zhi-Bin;Ren, Ze-Fang;Wang, Shen-Ming
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권6호
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    • pp.2759-2763
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    • 2012
  • Objectives: Compared with Western countries, the incidence rates for breast cancer in China are still low. However, breast cancer appears to be hitting Chinese women at a much younger age, with a peak between 40 and 50 years. Furthermore, breast tumors of Asian women have molecular and genetic characteristics that are different from those of Caucasian women. Methods: A community-based study was designed to evaluate the relationship between lifestyles and breast cancer risk in Chinese women residing in Guangzhou. 16,314 subjects completed the questionnaire. Potential confounding factors included sociodemographic characteristics. Results: 33 individuals reported a history of breast cancer, yielding a prevalence rate of 202.3/100000. Associations between subjects' demographic and breast cancer risk factors were assessed. Breast cancer is associated with family history of breast cancer, X-rays received, benign breast disease and hyperlipoidemia or hypercholesteremia with elevated odds ratios. Conclusions: Family history of breast cancer, X-ray received benign breast disease and hyperlipoidemia or hypercholesteremia were significantly associated with risk of breast cancer and may havepotential for breast cancer risk assessment.

서울 지역에서 분진에 대한 장기 추세 연구 (Long term trend for particular matters in Seoul)

  • 박혜련;최기헌
    • Journal of the Korean Data and Information Science Society
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    • 제20권5호
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    • pp.765-777
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    • 2009
  • 본 연구에서는 대기오염물질 중에서 주목을 받고 있는 분진 직경이 10마이크로미터 (micrometer) 이내의 것을 대상으로 실제로 증가하는지 감소하는지를 알아보기 위하여 교락 요인을 제외한 분진을 대상으로의 순수한 장기 추세를 연구하였다. 자료는 1996년에서 2000년까지 서울시의 기상 변수들 (최대기온, 평균습도, 최대풍속, 일사량)과 27지점에서 얻은 분진 직경이 10마이크로미터 이내의 것을 이용한다. 이 자료를 이용하여 분진과 비선형 관계를 보이는 기상 변수들의 회귀 스플라인을 이용하여 계절성을 통제한 일반화 부가모형을 세웠다. 그 결과 증가가 아닌 감소하는 순수 장기 추세를 얻을 수 있었다.

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