• Title/Summary/Keyword: Cutoff points

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Optimal Waist Circumference for the Prevention of Cardiovascular Disease (심혈관계질환의 발병 위험을 선별할 수 있는 적정 허리둘레의 임계점)

  • Baik, In-Kyung;Shin, Chol
    • Korean Journal of Community Nutrition
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    • v.15 no.2
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    • pp.275-283
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    • 2010
  • There are few studies reporting optimal waist circumference that can be utilized to prevent the incidence of cardiovascular disease (CVD). We evaluated the association of waist circumference and waist and hip circumference ratio (WHR) with incident cases of CVD developed over 6 years in a population-based prospective study including Korean adults. Analyses for receiver-operating characteristic (ROC) curve were performed with data for 1,733 men and 1,579 women who were aged 40 to 69 years and were free of a physician-diagnosis of CVD at baseline. Information on the diagnosis of CVD was periodically reported using interviewer-administered questionnaires and anthropometric measures were obtained by biennial health examinations. We newly identified 77 cases of CVD during a follow-up period between 2003 and 2008. On the basis of measures of diagnostic accuracy including minimum distance to ROC curve and Youden index, waist circumference of 85 cm for men, in particular for male nonsmokers, and of 80 cm for women and WHR of 0.88 to 0.90 for men and of 0.83 for women were found to be optimal cutoff points to identify individuals at CVD risks. The study also found that the use of the suggested optimal values for waist circumference show higher sensitivity and lower specificity compared with 90 cm for men and 85 cm for women, which are waist cutoff points given by the Korean Society for the Study of Obesity to define abdominal obesity for Korean adults. Although lower cutoff points of waist circumference (83 cm) and WHR (0.87) were observed to be optimal for male smokers compared with male nonsmokers, whether suggesting waist cutoff points specific to smokers is needed warrants further studies. After taking into account other cardiovascular risk factors including smoking, men with waist circumference of 85 cm or greater and women with 80 cm or greater were at an increased risk of CVD. Thus, these cutoff points of waist circumference may be able to capture more individuals at CVD risks contributing to the prevention of future development of CVD.

A Note on Parametric Bootstrap Model Selection

  • Lee, Kee-Won;Songyong Sim
    • Journal of the Korean Statistical Society
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    • v.27 no.4
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    • pp.397-405
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    • 1998
  • We develop parametric bootstrap model selection criteria in an example to fit a random sample to either a general normal distribution or a normal distribution with prespecified mean. We apply the bootstrap methods in two ways; one considers the direct substitution of estimated parameter for the unknown parameter, and the other focuses on the bias correction. These bootstrap model selection criteria are compared with AIC. We illustrate that all the selection rules reduce to the one sample t-test, where the cutoff points converge to some certain points as the sample size increases.

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Developing Scales for the Assessment of Fatigue in Turkish Pediatric Oncology Patients Aged 13-18 and their Parents

  • Bektas, Murat;Kudubes, Asli Akdeniz
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.22
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    • pp.9891-9898
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    • 2014
  • Background: This study was planned in an attempt to develop scales for the assessment of fatigue in pediatric oncology patients aged 13-18 and also for their parents. Materials and Methods: In collecting the study data, we used the Child and Parent Information Form, Visual Fatigue Scale, Scale for the Assessment of Fatigue in Pediatric Oncology Patients Aged 13-18 and the Scale for the Assessment of Fatigue in Pediatric Oncology Patients Aged 13-18 for Parents. We also used Pearson correlation analysis, Cronbach alpha coefficient, factor analysis and ROC analysis for the study data. Results: In this study, the total Cronbach alpha value of the parent form was 0.99, the total factor load was 0.72-0.94 with 95% the total variance being explained. The cutoff point of the parent form is 73 points. The total Cronbach alpha value of the child form was 0.99, the total factor load was 0.82-0.95, with 89.4% of the total variance being explained. The cutoff point of the child form was 75.5 points. Conclusions: This study suggests that the Scale for the Assessment of Fatigue in Pediatric Oncology Patients Aged 13-18 and the Scale for the Assessment of Fatigue in Pediatric Oncology Patients Aged 13-18 for Parents are valid and reliable instruments in assessing the fatigue symptoms of children in Turkey.

Developing a Scale for the Assessment of Fatigue in Pediatric Oncology Patients Aged 7-12 for Children and Parents

  • Kudubes, Asli Akdeniz;Bektas, Murat;Ugur, Ozlem
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.23
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    • pp.10199-10207
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    • 2015
  • Background: This study was planned in an attempt to develop scales for the assessment of fatigue in pediatric oncology patients aged 7-12 as well as for their parents. Materials and Methods: In collecting the study data, we used the Child and Parent Information Form, Visual Fatigue Scale, Scale for the Assessment of Fatigue in Pediatric Oncology Patients Aged 7-12 and the Scale for the Assessment of Fatigue in Pediatric Oncology Patients Aged 7-12 for Parents. We also used Pearson correlation analysis, the Cronbach Alpha coefficient, Factor Analysis and ROC Analysis for the study data. Results: In this study, the total Cronbach alpha value of the parent form was 0.95, the total factor load was 0.52-0.95 and the total variance being explained was 85.7%. The cutoff point of the parent form was 82 points. The total Cronbach alpha value of the child form was 0.98, the total factor load was 0.71-0.94 and the total variance being explained was 84.7%. The cutoff point of the child form was 75 points. Conclusions: This study suggests that our scales for the assessment of fatigue in pediatric oncology patients aged 7-12 and their parents are valid and reliable instruments.

Iron Nutriture and Related Dietary Factors in Apparently Healthy Young Korean Women(1) : Comparison and Evaluation of Blood Bichemical Indices for Assessment of Iron Nutritional Status (우리나라 젊은 성인 여성의 철분영양상태와 이에 영향을 미치는 식이요인 분석(1) : 혈액의 철분 영양 상태 평가 지표의 비교 및 분석)

  • 계승희
    • Journal of Nutrition and Health
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    • v.26 no.6
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    • pp.692-702
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    • 1993
  • To evaluate iron nutritional status and to compare biochemical indices used for evaluation of iron nutriture, fasting blood sample was taken from 96 Korean female college student and hemoglobin(Hb) concentration, hematocrit(Hct), serum iron, total iron binding capacity(TIBC) and serum ferritin concentration were measured and transferrin(TF) saturation was calculated. Prevalence of iron deficiency varied from 4.2% when judged from Hb concentration and Hct to 38.5% and 40.6% when TIBC and serum ferritin concentration were used. TIBC was negatively correlated with serum ferritin(r=0.4561, p<0.001), while other indices showed positive but less significant correlations(p<0.05). Regarding iron status judged by serum ferritin was regarded as true iron status, the present cutoff points of Hb, Hct, serum iron, TF saturation were very insensitive in identifying the subjects with iron deficiency. Only TIBC was suitable for detecting iron deficiency in the study subjects. It is concluded from the study results that iron deficiency in young Korean adult women would be significantly underestimated with presently used biochemical measurements except TIBC and new cutoff points of these indices were proposed based on sensitivity, specificity measured prevalence, and positive and negative predictive values.

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Bandwidth Limitations of the TEM Cell due to Higher Order Modes (고차 모드로 인한 TEM Cell의 대역 제한)

  • 이애경;이상회;김정기
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.28A no.11
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    • pp.866-873
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    • 1991
  • In this paper the electric and magnetic field distributions in a TEM cell used for EMC testing are analyzed numerically. The fields are distorted with the increase of frequency. These distortions are due to higher order modes and resonances and cause the bandwidthe limitations in the uae of TEM cels. The upper frequency is lower modes however, are reflected at some points through the tapered ends of the cell. Higher order modes however, are reflected at some points within the tapered region where it becomes too small to support the modes, The first two TE mode(TE$_{01}$ and TE$_{10}$) cutoff frequencies and the first six TE$_mnp$ resonant ferquencies are identified in a TEM cell (1x0 6x2m,w=0.72m) from field patterns and the results are consistent with others' data. The circumferential wall currents to support resonances are shown. For the large cell it is desired to extend the usable frequency range above the cutoff frequency of the first higher order mode. This study proposes an attempt to expand the frequency bandwidth by a resonance suppression.

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Developing a Scale for Quality of Life in Pediatric Oncology Patients Aged 7-12 - Children and Parent Forms

  • Kudubes, Asli Akdeniz;Bektas, Murat
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.2
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    • pp.523-529
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    • 2015
  • Background: This study was planned in an attempt to develop a scale for the quality of life in pediatric oncology patients aged 7-12, with child and parents forms. Materials and Methods: In collecting the study data, we used the Child and Parent Information Form, Visual Quality of Life Scale, Scale for Quality of Life Pediatric Oncology Patients Aged 7-12 and the Scale for the Quality of Life in Pediatric Oncology Patients Aged 7-12 for Parents. We also used Pearson correlation analysis, the Cronbach alpha coefficient, factor analysis and ROC analysis for the study data. Results: In this study, the total Cronbach alpha value of the parent form was 0.96, the total factor load being 0.54-0.90 and the total variance explained was 82.5%. The cutoff point of the parent form was 93 points. The total Cronbach alpha value for the child form was 0.96, with a total factor load of 0.55-0.91 and the total variance being explained was 78.3%. The cutoff point of the child form was 65 points. Conclusions: This study suggests that the Scale for Quality of Life in Pediatric Oncology Patients Aged 7-12 Child and Parents Forms are valid and reliable instruments in assessing the quality of life of children.

Mid-upper-arm circumference as a screening measure for identifying children with elevated body mass index: a study for Pakistan

  • Asif, Muhammad;Aslam, Muhammad;Altaf, Saima
    • Clinical and Experimental Pediatrics
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    • v.61 no.1
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    • pp.6-11
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    • 2018
  • Purpose: Mid-upper-arm circumference (MUAC) is considered an alternative screening method for obesity. The aims of this investigation were to examine the ability of MUAC to correctly identify children with elevated body mass index (BMI) and to determine the best MUAC cutoff point for identification of children with high BMI. Methods: Anthropometric measurements (height, weight, and MUAC) from a cross-sectional sample of 7,921 Pakistani children aged 5-14 years were analyzed. Pearson correlation coefficients between MUAC and other anthropometric measurements were calculated. Receiver operating characteristic curve analysis was used to determine the optimal MUAC cutoff point for identifying children with high BMI. Results: Among 7,921 children, the mean (${\pm}$standard deviation) age, BMI, and MUAC were 10.00 (${\pm}2.86years$), 16.16 (${\pm}2.66kg/m^2$), and 17.73 (${\pm}2.59cm$), respectively. The MUAC had a strong positive correlation with BMI. The optimal MUAC cutoff points indicating elevated BMI in boys ranged from 16.76 to 22.73, while the corresponding values in girls ranged from 16.38 to 20.57. Conclusion: MUAC may be used as a simple indicator of overweight/obesity in children, with reasonable accuracy in clinical settings.

A Study on the Reliability and Validity of the Five-Visceral Weak Children Questionnaire for Children with Anorexia (식욕부진 소아 대상 오장허약아 설문지의 신뢰도 및 타당도 연구)

  • Ko Mi Mi;Lee Sun Haeng;Chang Gyu Tae;Lee Boram
    • The Journal of Pediatrics of Korean Medicine
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    • v.38 no.2
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    • pp.1-10
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    • 2024
  • Objectives This study aimed to assess the reliability and validity of the Five-Visceral Weak Children Questionnaire (FWCQ) in childhood anorexia and to propose optimal cutoff values. Methods We conducted two surveys, spaced one month apart, targeting the parents of 366 children aged 2-9 years who had been diagnosed with anorexia for at least one month. To evaluate the reliability of the FWCQ, we calculated Cronbach's alpha coefficient and employed the test-retest method. Additionally, correlation analysis was performed between the FWCQ and each visceral question, and discriminant validity was assessed by comparing responses from the anorexic and normal groups. Furthermore, we determined the cutoff value of the spleen weak score, which is closely associated with appetite, for the anorexic group. Results The first survey yielded responses from 336 participants, followed by 171 responses in the second survey conducted one month later. The FWCQ demonstrated high internal consistency (Cronbach's alpha = 0.776), and test-retest results were consistent. The correlation coefficients between the FWCQ and each visceral question were all statistically significant. Moreover, significant discriminant validity was observed between the anorexic and normal groups in the FWCQ score and the heart, spleen, and kidney weak scores. The optimal cutoff value for the spleen weak score in the anorexic group was found to be 5.5 points (with a sensitivity of 73.44% and specificity of 66.47%). Conclusions The FWCQ exhibited strong reliability and validity in children with anorexia.

A study of coupling mechanism between two dipoles integrated within a conductor-backed thin dieelectric layer above earth using asymptotic evaluation (점근적 근사를 사용한 지표면 위에 놓여 있는 한쪽 면이 도체로 된 얇은 유전체 층 내부의 두 다이폴 사이의 상호 결합 원리에 관한 연구)

  • 박동국;라정웅
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.34D no.1
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    • pp.8-13
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    • 1997
  • An electric field due to point dipole within conductor-backed thin dielectric layer above the earth is calculated by using saddle point method When the dielectric layer is thin enough to support a cutoff mdoe, we show that the field may be approximated by sum of contributions of branch points of TE mode and poles of tM mode and that the branch points and poles contributions are interpreted as an evanescent lateral waves and leaky waves, respectively.

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