• Title/Summary/Keyword: mortality function

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Marriage, Sex Role, and Mortality : A Comparison Between Korea and the United States (결혼, 성역할 및 사망력 : 한.미 비교연구)

  • 박경애
    • Journal of Families and Better Life
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    • v.10 no.2
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    • pp.51-59
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    • 1992
  • Previous studies indicated that unmarried persons are subject to higher mortality than the married, and that the differentials are more marked for male than for females. There are two major approaches to explaining the marital status differentials in mortality ; selection function and protection function of marriage. Following protection fucntion, this study develops the new "instrumental / expressive sex-role" hypothesis in order to explain why marriage protects males more against death. The hypothesis expects that male's instrumental role and female's expressive role have direct effect as well as indirect effect through social integration on sex differential mortality by marital status. for the hypothesis testing, Korea and US vital statistics and census data are used to compute age-specific , age-adjusted mortality rates and their ratios for persons in different marital status. Major findings are as follows. 1)For both Korea and US being married is more advantageous to males than females, ad being widowed, divorced, and separated is more disadvantageous to males, while being never-married is more disadvantageous to females, 2) For Korea, the never married men and women have the highest mortality rates, 3) For US the never married women have the highest mortality rate, while the divorced, separated, and widowed men have the highest mortality rate. Fro both Korea and US data, selection function is rejected, but instrumental/expressive sex-role hypothesis succeeds in accounting for the sex and marital status differential in mortality.

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Effect Modification of Kidney Function on the Non-linear Association Between Serum Calcium Levels and Cardiovascular Mortality in Korean Adults

  • Jung-Ho Yang;Sun-Seog Kweon;Young-Hoon Lee;Seong-Woo Choi;So-Yeon Ryu;Hae-Sung Nam;Hye-Yeon Kim;Min-Ho Shin
    • Journal of Preventive Medicine and Public Health
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    • v.56 no.3
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    • pp.282-290
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    • 2023
  • Objectives: This study aimed to evaluate the potential interaction between kidney function and the non-linear association between serum calcium levels and cardiovascular disease (CVD) mortality. Methods: This study included 8927 participants enrolled in the Dong-gu Study. Albumin-corrected calcium levels were used and categorized into 6 percentile categories: <2.5th, 2.5-25.0th, 25.0-50.0th, 50.0-75.0th, 75.0-97.5th, and >97.5th. Restricted cubic spline analysis was used to examine the non-linear association between calcium levels and CVD mortality. Cox proportional hazard regression was used to estimate hazard ratios (HRs) for CVD mortality according to serum calcium categories. All survival analyses were stratified by the estimated glomerular filtration rate. Results: Over a follow-up period of 11.9±2.8 years, 1757 participants died, of whom 219 died from CVD. A U-shaped association between serum calcium and CVD mortality was found, and the association was more evident in the low kidney function group. Compared to the 25.0-50.0th percentile group for serum calcium levels, both low and high serum calcium tended to be associated with CVD mortality (<2.5th: HR, 6.23; 95% confidence interval [CI], 1.16 to 33.56; >97.5th: HR, 2.56; 95% CI, 0.76 to 8.66) in the low kidney function group. In the normal kidney function group, a similar association was found between serum calcium levels and CVD mortality (<2.5th: HR, 1.37; 95% CI, 0.58 to 3.27; >97.5th: HR, 1.65; 95% CI, 0.70 to 3.93). Conclusions: We found a non-linear association between serum calcium levels and CVD mortality, suggesting that calcium dyshomeostasis may contribute to CVD mortality, and kidney function may modify the association.

A Study on the Sorting Effect in Aquafarm (양식선별효과에 관한 연구)

  • EH, Youn-Yang;Song, Dong-Hyo
    • The Journal of Fisheries Business Administration
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    • v.49 no.4
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    • pp.19-36
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    • 2018
  • Overstock in aquaculture is a matter of concern in aquaculture management. To sort fish based on fingerling size in case of overstocking is an important problem in aquaculture farm. This study aims to determine the amount of fry overstock and sorting time in aquaculture farm. This study builds a mathematical model that finds the value of decision variables to optimize objective function summing up the fingerling purchasing cost, aquaculture farm operating cost and feeding cost under mortality and farming period constraints. The proposed mathematical model involves following biological and economical variables and coefficients: (1) number of fingerlings, (2) sorting time, (3) fish growth rate and variation, (4) mortality, (5) price of a fry (6) feeding cost, and (7) possible sorting periods. Numerical simulation is presented herein. The objective of numerical simulation is to provide decision makers to analyse and comprehend the proposed model. When extensive biological data about growth function of fry becomes available, the proposed model can be widely applicable to real aquaculture farms.

An analysis of the potential impact of various ozone regulatory standards on mortality

  • Kim, Yong-Ku
    • Journal of the Korean Data and Information Science Society
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    • v.22 no.1
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    • pp.125-136
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    • 2011
  • Ground-level ozone, an air pollutant that is monitored by the Environmental Protection Agency (EPA), damages human health by irritating the respiratory system, reducing lung function, damaging lung cells, and aggravating asthma and other chronic conditions. In March 2008, the EPA strengthened ozone standards by lowering acceptable limits from 84 parts per billion to 75 parts per billion. Here epidemiologic data is used to study the effects of ozone regulation on human health and assessed how various regulatory standards for ozone may affect nonaccidental mortality, including respiratory-related deaths during ozone season. The assessment uses statistical methods based on hierarchical Bayesian models to predict the potential effects of the different regulatory standards. It also analyzes the variability of the results and ho they are impacted by different modeling assumptions. We focused on the technical an statistical approach to assessing relationship between new ozone regulations and mortality while other researches have detailed the relationship between ozone and human mortality. We shows a statistical correlation between ozone regulations and mortality, with lower limits of acceptable ozone linked to a decrease in deaths, and projects that mortality is expected to decrease by reducing ozone regulatory standards.

Left Ventricular Ejection Fraction Predicts Poststroke Cardiovascular Events and Mortality in Patients without Atrial Fibrillation and Coronary Heart Disease

  • Lee, Jeong-Yoon;Sunwoo, Jun-Sang;Kwon, Kyum-Yil;Roh, Hakjae;Ahn, Moo-Young;Lee, Min-Ho;Park, Byoung-Won;Hyon, Min Su;Lee, Kyung Bok
    • Korean Circulation Journal
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    • v.48 no.12
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    • pp.1148-1156
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    • 2018
  • Background and Objectives: It is controversial that decreased left ventricular function could predict poststroke outcomes. The purpose of this study is to elucidate whether left ventricular ejection fraction (LVEF) can predict cardiovascular events and mortality in acute ischemic stroke (AIS) without atrial fibrillation (AF) and coronary heart disease (CHD). Methods: Transthoracic echocardiography was conducted consecutively in patients with AIS or transient ischemic attack at Soonchunhyang University Hospital between January 2008 and July 2016. The clinical data and echocardiographic LVEF of 1,465 patients were reviewed after excluding AF and CHD. Poststroke disability, major adverse cardiac events (MACE; nonfatal stroke, nonfatal myocardial infarction, and cardiovascular death) and all-cause mortality during 1 year after index stroke were prospectively captured. Cox proportional hazards regressions analysis were applied adjusting traditional risk factors and potential determinants. Results: The mean follow-up time was $259.9{\pm}148.8days$ with a total of 29 non-fatal strokes, 3 myocardial infarctions, 33 cardiovascular deaths, and 53 all-cause mortality. The cumulative incidence of MACE and all-cause mortality were significantly higher in the lowest LVEF (<55) group compared with the others (p=0.022 and 0.009). In prediction models, LVEF (per 10%) had hazards ratios of 0.54 (95% confidence interval [CI], 0.36-0.80, p=0.002) for MACE and 0.61 (95% CI, 0.39-0.97, p=0.037) for all-cause mortality. Conclusions: LVEF could be an independent predictor of cardiovascular events and mortality after AIS in the absence of AF and CHD.

Study of age specific lung cancer mortality trends in the US using functional data analysis

  • Tharu, Bhikhari;Pokhrel, Keshav;Aryal, Gokarna;Kafle, Ram C.;Khanal, Netra
    • Communications for Statistical Applications and Methods
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    • v.28 no.2
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    • pp.119-134
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    • 2021
  • Lung cancer is one of the leading causes of cancer deaths in the world. Investigation of mortality rates is pivotal to adequately understand the determinants causing this disease, allocate public health resources, and apply different control measures. Our study aims to analyze and forecast age-specific US lung cancer mortality trends. We report functions of mortality rates for different age groups by incorporating functional principal component analysis to understand the underlying mortality trend with respect to time. The mortality rates of lung cancer have been higher in men than in women. These rates have been decreasing for all age groups since 1990 in men. The same pattern is observed for women since 2000 except for the age group 85 and above. No significant changes in mortality rates in lower age groups have been reported for both gender. Lung cancer mortality rates for males are relatively higher than females. Ten-year predictions of mortality rates depict a continuous decline for both gender with no apparent change for lower age groups (below 40).

ESTIMATION AND SENSITIVITY OF GOMPERTZ PARAMETERS WITH MORTALITY DECELERATION RATE

  • PITCHAIMANI M.
    • Journal of applied mathematics & informatics
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    • v.18 no.1_2
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    • pp.311-320
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    • 2005
  • Studies in the evolutionary biology of aging require good estimates of the age-dependent mortality rate coefficient (one of the Gompertz parameters). In this paper we introduce an alternative algorithm for estimating this parameter. And we discuss the sensitivity of the estimates to changes in the other model parameters.

Correlation of Preoperative Pulmonary Function Testing and with Pulmonary Complication in Patients after Pneumonectomy (술전 폐기능과 전폐적출술후 폐합병증과의 연관성)

  • Bae, Byeong-U;Jeong, Hwang-Gyu
    • Journal of Chest Surgery
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    • v.26 no.8
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    • pp.620-626
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    • 1993
  • Determination of preoperatibe pulmonary function is crucial in avoiding complications from pulmonary resection, especially pneumonectomy. Postoperative morbidity and mortality were correlated with the preoperative results of five widely used tests of pulmonary function in 40 patients who underwent pneumonectomy for bronchiectasis, pulmonary tuberculosis, and carcinoma of the lung. Factors analyzed following operation included 30-day mortality, the incidence of arrhythmia, the frepuency of respiratory complications, and the number of individuals requiring prolonged mechanical ventilation. There were statistically significant differences[p<0.001]in mean values among FVC, FEV1, FEV1/FVC and MVV. But the difference of the FEF25-75% was not statistically significant.

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Ordering Model of Fingerlings in Aquaculture Farm (치어 주문모형에 관한 연구)

  • Eh, Youn-Yang;Song, Dong-Hyo
    • The Journal of Fisheries Business Administration
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    • v.48 no.3
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    • pp.47-59
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    • 2017
  • Fish mortality is the most important success factor in aquaculture management. To order fingerlings considering the effect of mortality is a important problem in aquaculture farm. This study is aimed to decision the number and size of fry in aquaculture farm. This study build the mathematical model that finds the value of decision variable to minimize total cost that sums up the fingerling purchasing cost, aquaculture farm operating cost and feeding cost under mortality constraint. The proposed mathematical model involve biological and economical variables: (1) number of fingerlings (2) fish growth rate (3) mortality (4) price of a fry (5) feeding cost, and (6) possible order period. Numerical simulation model presented here in. The objective of numerical simulation is to provide for decision makers to analyse and comprehend the proposed model. When extensive biological and cost data become available, the proposed model can be widely applied to yield more accurate results.

Cost Analysis Model according to Mortality in Land-based Aquaculture (육상수조 어류양식 생존율에 따른 비용분석모형)

  • Eh, Youn-Yang
    • The Journal of Fisheries Business Administration
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    • v.47 no.4
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    • pp.1-13
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    • 2016
  • Fish mortality is the most important success factor in aquaculture management. To analyze the effect of mortality considering biological and economic condition is a important problem in land-based aquaculture. This study is aimed to analyze the effect of mortality for duration of cultivation in land-based aquaculture. This study builds the mathematical model that finds the value of decision variable to minimize cost that sums up the water pool usage cost, sorting cost, fingerling cost and feeding cost under critical standing corp constraint. The proposed mathematical model involves many aspects, both biological and economical: (1) number of fingerlings (2) timing and number of batch splitting event, based on (3) fish growth rate, (4) mortality, and (5) several farming expense. Numerical simulation model presented here in. The objective of numerical simulation is to provide for decision makers to analyse and comprehend the proposed model. When extensive biological and cost data become available, the proposed model can be widely applied to yield more accurate results.