• Title/Summary/Keyword: Cohort model

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Skeletal stability following mandibular advancement: is it influenced by the magnitude of advancement or changes of the mandibular plane angle?

  • Tabrizi, Reza;Nili, Mahsa;Aliabadi, Ehsan;Pourdanesh, Fereydoun
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.43 no.3
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    • pp.152-159
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    • 2017
  • Objectives: The aim of this study was to investigate the effects of advancement magnitude and changes in mandibular plane angle on the stability of mandibular advancement. Materials and Methods: This retrospective cohort study evaluated the postoperative stability of mandibular advancement in class II skeletal subjects who underwent bilateral sagittal split osteotomy. Radiographs taken preoperatively, immediately postoperatively and 1 year postoperatively were traced and analyzed using linear and angular measurements. To determine horizontal and vertical relapse, an X-Y coordinate system was established in which the X-axis was constructed by rotating S-N downward by $7^{\circ}$ (approximation of the Frankfort horizontal plane) and the Y-axis was defined as a line perpendicular to the X-axis and passing through the point Sella. For certain reference points including point A, point B, pogonion and menton, the perpendicular distance between each point and both axes was determined and cephalometric variables were recorded as X and Y coordinates. Results: Twenty-five subjects were studied. A significant correlation between the amount of mandibular advancement and relapse in the B point (vertical and horizontal) and the pogonion point was observed (vertical and horizontal, P<0.001). Evaluation of data demonstrated a positive correlation between the mandibular plane angle (SN/ML) change and vertical relapse in the B point (P<0.05). A simple regression model demonstrated that 74% of horizontal relapse and 42.3% of vertical relapse in the B point was related to the amount of mandibular advancement. The receiver operating characteristic test showed that 8.5 mm mandibular advancement is related to a relapse rate of 1 mm or more in the pogonion, vertically or horizontally. Conclusion: The magnitude of mandibular advancement is a stronger surgical predictor for horizontal rather than vertical relapse at the B point. Changes in mandibular plane angle (SN/ML) during surgery affect vertical, but not horizontal relapse at the B point.

Associations of serum levels of vitamins A, C, and E with the risk of cognitive impairment among elderly Koreans

  • Kim, Sung Hee;Park, Yeong Mi;Choi, Bo Youl;Kim, Mi Kyung;Roh, Sungwon;Kim, Kyunga;Yang, Yoon Jung
    • Nutrition Research and Practice
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    • v.12 no.2
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    • pp.160-165
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    • 2018
  • BACKGROUND/OBJECTIVES: Korea is quickly becoming an aged society. Dementia is also becoming a vital public health problem in Korea. Cognitive impairment as a pre-stage of dementia shares most risk factors for dementia. The aim of the present study was to determine associations of serum levels of vitamins A, C, and E with the risk of cognitive impairment among elderly Koreans. SUBJECTS/METHODS: In this cross-sectional study, a total of 230 participants aged 60-79 years from Yangpyeong cohort were included. Cognitive function was assessed by the Korean version of the Mini-Mental State Examination for Dementia Screening. The logistic multivariable regression model was applied to determine the effect of serum vitamins A, C, and E on the risk of cognitive impairment. RESULTS: There was no significant association between the risk of cognitive impairment and serum levels of vitamin A and vitamin C. There was a significant odd ratio when the second tertile group of beta-gamma tocopherol level was compared to the first tertile group [odds ratio (OR) = 0.37, 95% confidence interval (CI) = 0.14-0.98, P for trend = 0.051]. In subgroup analyses, there were significant negative associations between beta-gamma tocopherol level and the risk of cognitive impairment in men (OR = 0.17, 95% CI = 0.03-0.87, P for trend = 0.028), non-drinkers or former drinkers (OR = 0.13, 95% CI = 0.02-0.66, P for trend = 0.025), and non-smokers or former smokers (OR = 0.27, 95% CI = 0.09-0.82, P for trend = 0.017). CONCLUSION: Serum beta-gamma tocopherol levels tended to be inversely associated with the risk of cognitive impairment. Further prospective large-scaled studies are needed to examine this association.

The change in the fertility rates and the determinants of birth interval of Korean women (한국여성의 출산율 변화와 출산간격 영향요인)

  • Ryoo, Kee-Cheol;Piao, Ying-Hua
    • Korea journal of population studies
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    • v.32 no.1
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    • pp.1-23
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    • 2009
  • This paper uses a survey data to analyze the age-specific fertility rates, age-specific cumulative fertility rates, and ages of marriage of the five birth cohorts of Korean women born in the 1940s and thereafter. It was found that later cohorts reach their highest age-specific fertility rate at higher ages than earlier cohorts. The age-specific cumulative fertility rates of the 1950s and 1960 cohorts were found to be much lower than those of the immediately preceding cohorts, while those of the 1970s and 1980s cohorts were not different from those of the 1960s cohorts. Women belonging to later cohorts were found to get married at relatively higher ages. The estimation results of the hazard model show that women belonging to later cohorts and those with more schooling have a tendency to get married at higher ages. The effect of the birth cohorts is thought to be due to the economic, social, and cultural changes in Korea during the late 50 years or so. The time interval between a woman‘s marriage and first birth was found not to be affected by either the year of marriage or that of her birth. Also, those who remained employed for some time around their marriage and those with low schooling were found to have a lower first child birth hazard, which implies that married women’s employment status and family income play an important role in their decisions on childbirth.

A Converged Study on the Longitudinal Relationship between Self-esteem and Community Spirit in Adolescents: Focusing on the Data of KCYPS (청소년의 자아존중감과 공동체의식에 관한 종단적 융합연구 -한국아동·청소년패널조사를 중심으로-)

  • Choi, Jung-Hyun
    • Journal of Convergence for Information Technology
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    • v.9 no.12
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    • pp.62-70
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    • 2019
  • The study used cross-lagged path modeling to examine the longitudinal associations between self-esteem and community spirit among adolescents. This is a longitudinal study designed to examine the developmental changes of adolescents' self-esteem and community spirit in Korea. This study used the data collected by the Korean Children and Youth Panel Survey (KCYPS) from 2014 through 2016. Participants were surveyed from the 5th grade to the 7th, which belonged to the 1st elementary school cohort panel of the KCYPS. To be used as the data of this study, children should have all information at 3-time points: the 5th grade; 6th grade; 7th grade. The collected data were analyzed with PSAW 18.0 and AMOS statistical program. The participants in this study were 903 males (51.6%) and 847 females (48.4%). The level of self-esteem was 3.29±.51, 3.19±.55, and 3.15±.57 point at 5th grade, 6th grade, and 7th grade each. The level of community spirit was 3.12±.52, 3.09±.59, 3.15±.55 point respectively. Community spirit from elementary school to middle school is consistently predicted by previous self-esteem. Likewise self-esteem has a significant predictive effect on subsequent community spirit.

The Association Between Cancer and Network Structure of Depressive Symptoms (암과 우울증상 네트워크 구조의 연관성)

  • Hwang, Hwijin;Lee, Kyung Kyu;Lee, Seok Bum;Lee, Jung Jae;Kim, Kyoung Min;Kim, Dohyun
    • Korean Journal of Psychosomatic Medicine
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    • v.29 no.2
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    • pp.121-127
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    • 2021
  • Objectives : The characteristics of depressive symptoms in patients with cancer is different from those in control group. However, few research has focused on the association between depressive symptoms in cancer patients. The aim of this study was to compare the network structure of depressive symptoms between patients with cancer and normal control. Methods : This study was based on cohort data from Korea National Health and Nutrition Examination Survey in 2016-2018. The Patient health Quetionnaire-9 (PHQ-9) was used to assess depressive symptoms in 599 patients with cancer and 599 age-sex matched controls. We estimated network structure of depressive symptom using Isingfit model. Results : There was no significant difference of each PHQ-9 item score. There were strong associations between symptoms were concentration problem-psychomotor activity, anhedonia-depressed mood, and depressed mood-suicidal ideation in both groups. Strength centrality of worthlessness was significantly higher in patients with cancer. Conclusions : These results suggest that worthless is associated with other depressive symptoms more tightly in patients with cancer. Worthless can serve as important treatment targets for intervention of depression in patients with cancer.

Cost-Utility Analysis of Pegfilgrastim and Pegteograstim in Patients with Breast Cancer using Doxorubicin and Cyclophosphamide (Doxorubicin과 Cyclophosphamide를 투여받는 유방암 환자에서 Pegfilgrastim과 Pegteograstim의 비용-효용 분석)

  • Kwon, Su Ji;Geum, Min Jung;Kim, Jae Song;Son, Eun Sun;Kwon, Kyeng Hee
    • Journal of Korean Society of Health-System Pharmacists
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    • v.35 no.4
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    • pp.409-417
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    • 2018
  • Background : Febrile neutropenia (FN) is one of the side effects in the patients treated with chemotherapy, and the patients who have FN generally need immediate treatment with extended-spectrum antibiotics and hospitalization. Pegfilgrastim and pegteograstim, which are used for the prevention of FN as a granulocyte-colony stimulating factor (G-CSF), have been granted insurance coverage in the Republic of Korea for certain breast cancer patients using doxorubicin and cyclophosphamide (AC) from September 2016. Methods : The data of the patients with breast cancer using AC regimen and G-CSF were collected retrospectively. This study involves cost-utility analysis of pegfilgrastim and pegteograstim. In this study, we constructed a simple decision tree model for short-term observation and calculated quality-adjusted life year (QALY) and the direct medical costs from the medical provider's perspective. Results : From September 2016 to May 2017, 15 patients were treated with pegfilgrastim and 15 patients were treated with pegteograstim. As a result of dividing the average cost by QALY for each treatment group, it was observed that pegfilgrastim and pegteograstim were consumed 24,923,384 won and 22,808,336 won per 1QALY, respectively. Consequently, incremental cost effectiveness ratio (ICER) showed 2,115,048 won more per pegfilgrastim than pegteograstim per 1QALY, and the cost per 1QALY of both the drugs was lower than 30,500,000 won; the Koreans were willing to pay this amount. Conclusions : This study suggests that pegfilgrastim and pegteograstim can be used to improve the quality of life of breast cancer patients undergoing AC therapy. Among the two drugs, pegteograstim seems to be more cost-effective. However, since this study was conducted as a retrospective observation method on a small scale, it is associated with many limitations. Therefore, a long-term prospective cohort study is needed to supplement the present findings.

An Analysis of Change in Efficiency of Department of Early Childhood Education in KOREA (3주기 및 4주기 교원양성기관 평가 후 전국 대학 유아교육과 효율성 분석)

  • Song, Woon-Kyung;Song, Yun-Kyung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.5
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    • pp.517-529
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    • 2021
  • This study analyzes changes in the efficiency of the Department of Early Childhood Education in Korea to examine the effectiveness of the National Evaluation for Teacher Education Institution. We provide policy implications from exploring factors influencing efficiency and comparing characteristics of efficient and inefficient departments. With 149 Department of Early Childhood Education in Korea, DEA was conducted to estimate the relative efficiency, and the Tobit model was applied to explore factors affecting efficiency. The results confirm that the Department of Early Childhood in Korea is run efficiently, though there was no change in scale efficiency and relative efficiency after the two phases of the National Evaluation for Teacher Education Institution. The results show the number of books per student was significantly lower despite a significantly higher employment rate. Efficiency of college departments, department greater than 60 (per cohort), and department in metropolitan city (except Seoul area) is confirmed greater. These results provide policy implications on developing evaluation measure and processes to improve education quality and efficiency.

Association of Pre- and Perinatal Risk Factors With Tourette Syndrome or Chronic Tic Disorders in a Korean School-Age Population

  • Wooseok Choi;Soon-beom Hong;Johanna Inhynag Kim;Jung Lee;Soomin Jang;Yebin D Ahn;You Bin Lim;Sumin Kim;Mee Rim Oh;Bung-Nyun Kim
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.34 no.1
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    • pp.37-44
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    • 2023
  • Objectives: Tic disorders are highly heritable; however, growing evidence suggests that environmental factors play a significant role in their pathogenesis. Studies on these factors have been inconsistent, with conflicting results. Therefore, this study aimed to examine the associations of pre- and perinatal exposure to Tourette syndrome (TS) or chronic tic disorders (CTD) in Korean school-aged children. Methods: This case-control study used data from a large prospective cohort study. The primary outcome was TS/CTD diagnosis according to the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) criteria and Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version-Korean Version. Demographic, pre-, and perinatal information was obtained from the maternal questionnaires. Data between the TS/CTD and control groups were compared using the chi-squared or Student's t-test, as appropriate. Two-step logistic regression analyses were used to test the association between TS/CTD and pre- and perinatal risk factors. Results: We included of 223 children (78 with TS/CTD and 145 controls). Significant differences in the demographic data between the two groups were observed. The male sex ratio, mean parental age, parental final education level, and family history of tics were included as confounders. In the final adjusted multivariable model, TS/CTD was significantly associated with antiemetic exposure during pregnancy (odds ratio [OR]=16.61, 95% confidence interval [CI] 1.49-185.22, p=0.02) and medically assisted reproduction (OR=7.89, 95% CI 2.28-27.28, p=0.01). Conclusion: Antiemetic exposure and medically assisted reproduction are significantly associated with the risk of TS/CTD. These results should be replicated in future prospective and gene-by-environment studies.

The Moderating Effect of Gender in the Relationship between Physical Education and Adolescents' Internalizing and Externalizing Problem Behaviors: Using Multi-level Growth Modeling (체육시간과 청소년의 외현화·내재화 문제와의 관계에서 성별의 조절효과: 다층성장모형의 적용)

  • Taekho Lee;Seokyoung Lee;Yoonsun Han
    • Korean Journal of Culture and Social Issue
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    • v.21 no.2
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    • pp.131-158
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    • 2015
  • This study examined the relationship between physical education and externalizing(aggression) and internalizing(depression, social withdrawal) problem behaviors among adolescents. The moderating role of gender and time in the association between physical education and problem behavior was also identified. This study used data from the second, third, and fourth waves of the middle school student cohort (N=2,133, N=2,151, N=1,979) of the Korean Children-Youth Panel Survey(KCYPS). Main analyses involved multilevel growth model with interaction terms. The dependent variables were aggression, depression, and social withdrawal. The independent variables were gender and physical education (exercise hours) at school. The control variables were abuse, school-adjustment, annual household income and parents' highest level of education. The major longitudinal findings of this study are as follows: First, there was significant change according to the passage of time only in aggression among externalizing and internalizing problems. Second, gender differences exist in aggression and depression. Third, exercise hours of physical education had a negative relationship with internalizing problems. Fourth, there were no gender differences over time in both externalizing and internalizing problems. Fifth, the interaction between exercise hours of physical education and time was statistically significant for social withdrawal. Sixth, the interaction between exercise hours of physical education and gender was statistically significant for depression. The results of this study may become an academic basis for suggesting policy directions that promote increased exercise hours in physical education classes at school.

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Analysis of Job Creation Effects and Spatial Distribution Characteristics of Startups in Manufacturing at Different Technology Levels (기술수준별 제조창업의 공간분포 특성과 고용증가 효과 분석)

  • Hansoun Woo;Daehyun Seo
    • Journal of the Economic Geographical Society of Korea
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    • v.25 no.4
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    • pp.600-616
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    • 2022
  • This study contemplates spatial context of startup in manufacturing, mainly analyzing job creation effects of time lag of startups in manufacturing at different technology levels. Using DID model, we found that each region including capital, non-capital and metropolitan area shows different job creation effects of time lag. In capial region, startup cohort in high R&D intensity manufacturing was found to show short-term job creation effects, but in non-capital region, long-term job creation effects was found with the one in medium-high R&D intensity manufacturing. In case of metropolitan area, we couldn't find much evidence of job creation effects that was statistically significant. The result of analysis implied that, in capital region, startup support policies, targeting at high R&D intensity manufacturing, ought to be focused on scale-up of startups that survived for a certain period. And non-capital area and some of metropolitan areas in non-capital region that have comparatively inferior infrastructure and brain-drain problems as well should focus on fostering startups in medium-high R&D intensity manufacturing in a long-term perspective and utilize their traditional manufacturing base.