• Title/Summary/Keyword: likelihood ratio confidence interval

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Determinants of age at menarche in Korean elementary school girls (초등학교 여학생의 초경시기와 관련된 결정요인 분석)

  • Kwon, Mi-Kyoung;Seo, Eun Min;Park, Kyong
    • Journal of Nutrition and Health
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    • v.48 no.4
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    • pp.344-351
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    • 2015
  • Purpose: During the recent decades, the age at menarche continued to decline in Korea and worldwide. Prior studies have suggested that early menarche may increase the risk of various social, psychological, and physical health problems in young adolescent girls, but little is known about the determinants associated with early menarche. The purpose of this study is to evaluate independent determinants of early menarche among 5th~6th female graders in South Korea. Methods: Our analysis was conducted in 95 menarcheal girls and 95 age-matched pre-menarcheal girls residing in Daegu, South Korea. Demographic and lifestyle characteristics were collected using survey questionnaires for children and parents. Dietary information was assessed by 2 day~24 hour food records and survey questionnaires, which were completed by both children and their parents. Anthropometric data were obtained from the student health check-ups at the school. Results: A multiple logistic regression analysis using a conditional likelihood method was performed for simultaneous evaluation of several risk factors. There were significant differences in that higher proportion of obesity (OR, odds ratio = 5.60, 95% CI, confidence interval = 1.34~23.42), shorter sleep duration (OR = 0.45, 95% CI = 0.23~0.87), and younger mother's age at menarche (OR = 0.64, 95% CI = 0.44~0.93) were observed in the menarcheal group compared to the pre-menarcheal group. Conclusion: These findings indicate a possible association of sleep duration, mother's menarcheal age, and obesity with age at menarche. A well-planned, prospective cohort study is warranted to examine causal relationship.

Risk Factors of Delayed Surgical Intervention after Conservatively Treated Acute Traumatic Subdural Hematoma

  • Kwon, Hyungjoo;Choi, Kyu-Sun;Yi, Hyeong-Joong;Chun, Hyoung-Joon;Lee, Young-Jun;Kim, Dong-won
    • Journal of Korean Neurosurgical Society
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    • v.60 no.6
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    • pp.723-729
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    • 2017
  • Objective : Acute subdural hematoma (ASDH) is generally considered a condition that should be managed surgically. However, some patients initially receive conservative treatment, a subset of whom require surgical intervention later. This study aimed to evaluate the predictors of delayed surgical intervention in ASDH patients who are initially managed conservatively. Methods : From January 2007 to December 2015, 842 patients diagnosed with ASDH were treated at our institution. Among them, 158 patients with convexity ASDH were initially treated conservatively. Patients were divided into a delayed surgery group and a conservative group. Demographic characteristics, past medication and medical histories, and radiological and laboratory data were collected by retrospective chart review. Independent risk factors were identified with univariate and multivariate analyses. Results : Twenty-eight patients (17.7%) underwent delayed surgical intervention. Their mean age was 69.0 years, and 82.1% were male. Hypertension, diabetes mellitus, and heart disease prevalence and use of anti-platelet agents did not significantly differ from the conservative group. However, age (p=0.024), previous cerebral infarction history (p=0.026), increased maximal hematoma thickness (p<0.001), midline shifting (p=0.001) and accompanying subarachnoid hemorrhage (p=0.022) on initial brain computed tomography (CT) scan, low hemoglobin level (p<0.001), high leukocyte count (p=0.004), and low glucose level (p=0.002) were significantly associated with delayed surgical intervention. In multivariate analysis, increased maximal hematoma thickness (odds ratio [OR]=1.279, 95% confidence interval [CI] 1.075-1.521; p=0.006), low hemoglobin level (OR=0.673, 95% CI 0.467-0.970; p=0.034), and high leukocyte count (OR=1.142, 95% CI 1.024-1.272; p=0.017) were independent risk factors for delayed surgical intervention. Conclusion : Due to the high likelihood of delayed surgical intervention among minimal ASDH patients with a thicker hematoma on initial brain CT, lower hemoglobin level, and higher leukocyte count, these patients should receive more careful observation.

A Three-Dimensiomal Slope Stability Analysis in Probabilistic Solution (3차원(次元) 사면(斜面) 안정해석(安定解析)에 관한 확률론적(確率論的) 연구(研究))

  • Kim, Young Su
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.4 no.3
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    • pp.75-83
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    • 1984
  • The probability of failure is used to analyze the reliability of three dimensional slope failure, instead of conventional factor of safety. The strength parameters are assumed to be normal variated and beta variated. These are interval estimated under the specified confidence level and maximum likelihood estimation. The pseudonormal and beta random variables are generated using the uniform probability transformation method according to central limit theorem and rejection method. By means of a Monte-Carlo Simulation, the probability of failure is defined as; $P_f=M/N$ N: Total number of trials M: Total number of failures Some of the conclusions derived. from the case study include; 1. Three dimensional factors of safety are generally much higher than 2-D factors of safety. However situations appear to exist where the 3-D factor of safety can be lower than the 2-D factor of safety. 2. The $F_3/F_2$ ratio appears to be quite sensitive to c and ${\phi}$ and to the shape of the 3-D shear surface and the slope but not to be to the unit weight of soil. 3. From the two models (normal, beta) considered for the distribution of the factor of safety, the beta distribution generally provides lager than normal distribution. 4. Results obtained using the beta and normal models are presented in a nomgraph relating slope height and slop angle to probability of failure.

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A Study on the Application of Generalized Extreme Value Distribution to the Variation of Annual Maximum Surge Heights (연간 최대해일고 변동의 일반화 극치분포 적용 연구)

  • Kwon, Seok-Jae;Park, Jeong-Soo;Lee, Eun-Il
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.21 no.3
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    • pp.241-253
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    • 2009
  • This study performs the investigation of a long-term variation of annual maximum surge heights(AMSH) and main characteristics of high surge events, and the statistical evaluation of the AMSH using sea level data at Yeosu and Tongyeong tidal stations over more than 30 years. It is found that the long-term uptrends based on the linear regression in the AMSH are 34.5 cm/34 yr at Yeosu and 33.6 cm/31 yr at Tongyeong, which are relatively much higher than those at Sokcho and Mukho in the Eastern Coast. 71% and 68% of the AMSH occur during typhoon's event in Yeosu and Tongyeong tidal stations, respectively, and the highest surge records are mostly produced by the typhoon. The generalized extreme value distribution taking into account of the time variable is applied to detect time trend in annual maximum surge heights. In addition, Gumbel distribution is checked to find which one is best fitted to the data using likelihood ratio test. The return level and its 90% confidence interval are obtained for the statistical prediction of the future trend. The prevention of the growing storm surge damage by the intensified typhoon requires the steady analysis and prediction of the surge events associated with the climate change.

The likelihood of achieving pregnancy through timed coitus in young infertile women with decreased ovarian reserve

  • Koo, Hwa Seon;Song, In Ok;Cha, Sun Hwa;Park, Chan Woo;Kim, Hye Ok
    • Clinical and Experimental Reproductive Medicine
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    • v.45 no.1
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    • pp.31-37
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    • 2018
  • Objective: To evaluate the pregnancy rate and time to pregnancy after timed coitus with or without superovulation in infertile young women younger than 35 years old with low serum $anti-M{\ddot{u}}llerian$ hormone (AMH) levels ( < 25th percentile). Methods: A total of 202 patients younger than 35 years old were recruited retrospectively between 2010 and 2012. Ninety-eight women had normal serum AMH levels (25-75th percentile), 75 women had low serum AMH levels (5th ${\leq}$ & < 25th percentile) and 29 women had very low serum AMH levels ( < 5th percentile), according to reference values for their age group. Results: The clinical pregnancy rate was positively associated with AMH levels, but this trend did not reach statistical significance (43.9% vs. 41.3% vs. 27.6% in the normal, low, and very low AMH groups, respectively). The time to pregnancy was longer in the very low AMH group than in the normal AMH group ($13.1{\pm}10.9months$ vs. $6.9{\pm}6.1months$, p= 0.030). The cumulative live birth rate over 18 months was lower in the very low AMH group than in the normal AMH group, with marginal significance (20.0% vs. 55.9%, p= 0.051). The duration of infertility was negatively correlated with achieving pregnancy (odds ratio, 0.953; 95% confidence interval, 0.914-0.994; p= 0.026). Conclusion: Conservative management, such as timed coitus with or without superovulation, should be considered in young patients who have low ovarian reserve without any infertility factors. However, for women with a long duration of infertility or very low serum AMH levels, active infertility treatment should be considered.

Influences of Chronic Pain on the Use of Medical Services in South Korea (만성 통증이 한국의 의료 이용 행태에 미치는 영향)

  • Jeong, Eui-Kyun;Kwak, Yeun-Hee;Song, Jae-Seok
    • The Journal of the Korea Contents Association
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    • v.15 no.2
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    • pp.363-369
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    • 2015
  • Chronic pain is one of the leading causes of hospital visits. It not only affects the patients themselves but also has a major negative impact on their families and society. In this study, we investigated epidemiology of musculoskeletal disorders induced chronic pain among general population based on Korea National Health and Nutrition Examination Survey database and also analysed how it influenced on the use of medical services. This study was done by using the data of 5th Korea National Health and Nutrition Examination Survey (KNHANES V), taking aged 20 years and over adults as research subjects. The EuroQoL-5 Dimension Index(EQ-5D) was used as a survey instrument. T-test, chi-square test and multivariate logistic regression were used for statistical analysis. Subjects with chronic pain had a higher likelihood than control group to use medical services(odds ratio : 5.858, confidence interval 3.636-9.438). Controlling for existence of chronic pain, more women were likely to use medical services than men(1.156, 0.707-1.889). Age, gender and household income level did not affect the use of medical services. Proper control of chronic pain is very helpful in improving patient's quality of life and it also accounts for a large proportion in suppressing excessive consumption of medical services. Anesthesia and pain medicine specialists have superior knowledge about analgesics and anticonvulsants than other physicians do and also have specialized skills to perform procedures like nerve blocks in treating chronic pain. Therefore Anesthesia and pain medicine specialists need to play a leading role in managing chronic pain.

Investigation on Perceptions, Attitudes, and Contributing Factors to Spontaneous Adverse Drug Reaction Reporting among Community Pharmacists: Results from a Web-based Survey (지역 약사의 자발적 부작용 보고에 대한 인식 및 태도와 영향요인 조사: 설문조사 결과를 중심으로)

  • Lee, Mo-Se;Choi, Ah-Hyung;Jang, Bo-Hyun;Kim, Na-Young;Lee, Jung-Min;Shin, Ju-Young;Jeon, Ha-Lim
    • Korean Journal of Clinical Pharmacy
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    • v.29 no.2
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    • pp.125-132
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    • 2019
  • Objective: To examine the perceptions and attitudes toward spontaneous adverse drug reaction (ADR) reporting system among community pharmacists and identify factors that influence reporting, by implementing a survey. Methods: A structured questionnaire was developed and distributed online. Request for the survey was posted on the website of pharmacy's billing program, and the survey was conducted for 8 days. We collected the participants' response on their work environment, experience of ADR reporting, and their perception and attitude on the reporting system. Multivariate logistic regression was used to evaluate factors influencing ADR reporting. Results: A total of 382 pharmacists participated in the survey. Significant contributing factors for reporting level were age (odds ratio [OR], 0.90; 95% confidence interval [CI], 0.84-0.96), knowledge of reporting method (OR, 53.56; 95% CI, 9.10-315.41), installation of reporting program (OR, 31.92; 95% CI, 4.16-244.75), and encouragement from the Korean pharmaceutical association (OR, 4.13; 95% CI, 1.11-15.35). Regarding the attitude toward spontaneous ADR reporting system, 'lack of time for reporting' (OR, 0.29; 95% CI, 0.15-0.53) and 'complexity of reporting procedure' (OR, 0.51; 95% CI, 0.31-0.84), were associated with a low likelihood of reporting. Conclusion: Our results indicated that the knowledge of ADR reporting method, installation of the reporting program, and encouragement from the Korean Pharmaceutical Association contribute to active reporting. It is necessary to simplify the reporting method, make the ADR reporting program user-friendly, and provide educational interventions to increase participation in spontaneous reporting by the community pharmacists.

Antenatal Corticosteroids and Clinical Outcomes of Preterm Singleton Neonates with Intrauterine Growth Restriction

  • Kim, Yoo Jinie;Choi, Sung Hwan;Oh, Sohee;Sohn, Jin A;Jung, Young Hwa;Shin, Seung Han;Choi, Chang Won;Kim, Ee-Kyung;Kim, Han-Suk;Kim, Beyong Il;Lee, Jin A
    • Neonatal Medicine
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    • v.25 no.4
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    • pp.161-169
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    • 2018
  • Purpose: We assessed the influence of antenatal corticosteroid (ACS) on the inhospital outcomes of intrauterine growth restriction (IUGR) infants. Methods: A retrospective study was conducted with singletons born at $23^{+0}$ to $33^{+6}weeks$ of gestation at Seoul National University Hospital from 2007 to 2014. We compared clinical outcomes between infants who received ACS 2 to 7 days before birth (complete ACS), at <2 or >7 days (incomplete ACS), and those who did not receive ACS in IUGR and AGA infants. Multivariate logistic regression using Firth's penalized likelihood was performed. Results: 304 neonates with 91 IUGR neonates were eligible. Among AGA neonates, mortality (adjusted odds ratio [aOR], 0.13; 95% confidence interval [CI], 0.02 to 0.78), hypotension within 7 postnatal days (aOR, 0.20; 95% CI, 0.06 to 0.64), and severe bronchopulmonary dysplasia (BPD) or death (aOR, 0.24; 95% CI, 0.07 to 0.77) were lower in complete ACS group after adjusting for pregnancy induced hypertension and uncontrolled preterm labor. Mortality (aOR, 0.18; 95% CI, 0.04 to 0.78), hypotension (aOR, 0.26; 95% CI, 0.09 to 0.70), and severe BPD or death (aOR, 0.33; 95% CI, 0.12 to 0.92) were also lower in the incomplete ACS group. Among IUGR infants, after adjusting for birth weight and 5-minute Apgar score, inhaled nitric oxide use within 14 postnatal days was lower in both complete ACS (aOR, 0.07; 95% CI, 0.01 to 0.67) and incomplete ACS (aOR, 0.04; 95% CI, 0.01 to 0.37) groups. Conclusion: ACS was not effective in reducing morbidities in IUGR preterm infants.

Does the Obesity Paradox Exist in Cognitive Function?: Evidence from the Korean Longitudinal Study of Ageing, 2006-2016 (인지기능에 비만 역설은 존재하는가?: 고령화연구패널자료(2006-2016)를 이용하여)

  • Kang, Kyung Sik;Lee, Yongjae;Park, Sohee;Kimm, Heejin;Chung, Woojin
    • Health Policy and Management
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    • v.30 no.4
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    • pp.493-504
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    • 2020
  • Background: There have been many studies on the associations between body mass index (BMI) and cognitive function. However, no study has ever compared the associations across the methods of categorizing BMI. In this study, we aimed to fill the gap in the previous studies and examine whether the obesity paradox is valid in the risk of cognitive function. Methods: Of the 10,254 people aged 45 and older from the Korean Longitudinal Study of Ageing from 2006 to 2016, 8,970 people were finalized as the study population. The dependent variable was whether a person has a normal cognitive function or not, and the independent variables of interest were BMI categorized by the World Health Organization Western Pacific Regional Office (WHO-WPRO) method, the WHO method, and a 10-group method. Covariates included sociodemographic factors, health behavior factors, and health status factors. A generalized linear mixed model analysis with a logit link was used. Results: In the adjusted model with all covariates, first, in the case of BMI categories of the WHO-WPRO method, underweight (odds ratio [OR], 1.16; 95% confidence interval [CI], 1.15-1.17), overweight (OR, 1.36; 95% CI, 1.35-1.36), and obese (OR, 1.34; 95% CI, 1.33-1.34) groups were more likely to have a normal cognitive function than a normal-weight group. Next, in the case of BMI categories of the WHO method, compared to a normal-weight group, underweight (OR, 1.15; 95% CI, 1.14-1.16) and overweight (OR, 1.06; 95% CI, 1.06-1.07) groups were more likely to have a normal cognitive function; however, obese (OR, 0.62; 95% CI, 0.61-0.63) group was less likely to have it. Lastly, in the case of the 10-group method, as BMI increased, the likelihood to have a normal cognitive function changed like a wave, reaching a global top at group-7 (26.5 kg/㎡ ≤ BMI <28.0 kg/㎡). Conclusion: The associations between BMI and cognitive function differed according to how BMI was categorized among people aged 45 and older in Korea, which suggests that cognitive function may be positively associated with BMI in some categories of BMI but negatively in its other categories. Health policies to reduce cognitive impairment need to consider this association between BMI and cognitive function.

Factors Associated with the Use of Medical Care at Hospitals among Outpatients with Hypertension: A Study of the Korea Health Panel Study Dataset (2010-2016) (우리나라 고혈압 환자의 병원급 의료기관 외래이용 관련 요인: 한국의료패널자료(2010-2016)를 이용하여)

  • Lee, Sumi;Park, Sohee;Kimm, Heejin;Lee, Yongjae;Chung, Woojin
    • Health Policy and Management
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    • v.30 no.4
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    • pp.479-492
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    • 2020
  • Background: As the prevalence of hypertension is increasing in Korea, the government is seeking policy actions to manage patients with hypertension more efficiently. In this paper, we aimed to identify factors associated with the use of medical care at hospitals among outpatients with hypertension. Methods: We analyzed a total of 15,040 cases of 3,877 outpatients with hypertension obtained from the Korea Medical Panel database from 2010 to 2016. The dependent variable was whether a patient with hypertension visited a hospital or not; and independent variables were the patient's various socio-demographic, health-related, and heath-status characteristics. We conducted a generalized linear mixed model analysis with logit link for all the cases and then conducted it stratified by gender. Results: As a result of a multivariable analysis, women were less likely than to visit at a hospital (odds ratio [OR], 0.44; 95% confidence interval [CI], 0.32-0.61) and people aged 65 years and older than those aged less than 65 years (OR, 0.71; 95% CI, 0.57-0.89). Residents in Busan, Ulsan, and Gyeongnam were more likely than those in than Seoul, Gyeonggi, Incheon, and Jeju to visit a hospital (OR, 1.40; 95% CI, 1.05-1.86). The likelihood of visiting a hospital was high in people belonging to a group of: the highest level of annual household income (OR, 1.73; 95% CI, 1.30-2.29); Medical care aid recipients (OR, 1.94; 95% CI, 1.34-2.83); people having three or more complex chronic diseases (OR, 1.59; 95% CI, 1.19-2.11); people having diabetes (OR, 1.81; 95% CI, 1.41-2.32); or people having ischemic heart disease or cerebrovascular disease (OR, 6.80; 95% CI, 5.28-8.76). Also, we found that factors associated with the use of medical care at hospitals among outpatients with hypertension differed between genders. Conclusion: A variety of factors seem to be associated with the use of medical care at hospitals among outpatients with hypertension. Future research needs to find a way to help patients with hypertension visit an appropriate medical institution between clinics and hospitals.