• Title/Summary/Keyword: incidence estimation

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Risk Factors for Falls in Tertiary Hospital Inpatients: A Survival Analysis (상급종합병원 입원환자의 낙상 위험요인: 생존분석으로)

  • Cho, Young Shin;Lee, Young Ock;Youn, Young Sun
    • Journal of Korean Critical Care Nursing
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    • v.12 no.1
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    • pp.57-70
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    • 2019
  • Purpose : The purpose of this study was to identify the risk factors for falls in tertiary hospital inpatients and to suggest data for developing a nursing intervention program for preventing falls. Methods: Data were collected between January 1, 2017, to December 31, 2017. Kaplan-Meier estimation was used to measure the survival rate, and the log-rank test was used for the differences between the fall group and the non-fall group. The Cox proportional hazards model was used to identify the risk factors for falls. Results: The incidence rate of falls for the inpatients was 1.2 cases per 1,000 days of hospitalization. The risk factors for falls were more likely to be found among those who were aged ${\geq}81$, had not undergone surgery, had poor joint motion, had unsteady gait, needed help or supervision, used assistive devices, had comorbidity, and took at least two drugs. Conclusion: For the inpatients, the risk factors for falls included age, surgery, comorbidity, medication that could change mobility, joint motion, and use of patient care equipment. It is necessary to give special attention to inpatients who have any of these risk factors and to develop a falls risk assessment tool.

Risk Assessment for Toluene Diisocyanate and Respiratory Disease Human Studies

  • PARK, Robert M.
    • Safety and Health at Work
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    • v.12 no.2
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    • pp.174-183
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    • 2021
  • Background: Toluene diisocyanate (TDI) is a highly reactive chemical that causes sensitization and has also been associated with increased lung cancer. A risk assessment was conducted based on occupational epidemiologic estimates for several health outcomes. Methods: Exposure and outcome details were extracted from published studies and a NIOSH Health Hazard Evaluation for new onset asthma, pulmonary function measurements, symptom prevalence, and mortality from lung cancer and respiratory disease. Summary exposure-response estimates were calculated taking into account relative precision and possible survivor selection effects. Attributable incidence of sensitization was estimated as were annual proportional losses of pulmonary function. Excess lifetime risks and benchmark doses were calculated. Results: Respiratory outcomes exhibited strong survivor bias. Asthma/sensitization exposure response decreased with increasing facility-average TDI air concentration as did TDI-associated pulmonary impairment. In a mortality cohort where mean employment duration was less than 1 year, survivor bias pre-empted estimation of lung cancer and respiratory disease exposure response. Conclusion: Controlling for survivor bias and assuming a linear dose-response with facility-average TDI concentrations, excess lifetime risks exceeding one per thousand occurred at about 2 ppt TDI for sensitization and respiratory impairment. Under alternate assumptions regarding stationary and cumulative effects, one per thousand excess risks were estimated at TDI concentrations of 10 - 30 ppt. The unexplained reported excess mortality from lung cancer and other lung diseases, if attributable to TDI or associated emissions, could represent a lifetime risk comparable to that of sensitization.

Epidemiology of Low-Dose Ionizing Radiation Exposure and Health Effects (저선량 방사선 노출과 건강 영향에 대한 역학적 고찰)

  • Won Jin Lee
    • Journal of Environmental Health Sciences
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    • v.49 no.1
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    • pp.1-10
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    • 2023
  • Low-dose radiation exposure has received considerable attention because it reflects the general public's type and level of exposure. Still, controversy remains due to the relatively unclear results and uncertainty in risk estimation compared to high-dose radiation. However, recent epidemiological studies report direct evidence of health effects for various types of low-dose radiation exposure. In particular, international nuclear workers' studies, CT exposure studies, and children's cancer studies on natural radiation showed significantly increased cancer risk among the study populations despite their low-dose radiation exposure. These studies showed similar results even when the cumulative radiation dose was limited to an exposure group of less than 100 mGy, demonstrating that the observed excess risk was not affected by high exposure. A linear dose-response relationship between radiation exposure and cancer incidence has been observed, even at the low-dose interval. These recent epidemiological studies include relatively large populations, and findings are broadly consistent with previous studies on Japanese atomic bomb survivors. However, the health effects of low-dose radiation are assumed to be small compared to the risks that may arise from other lifestyle factors; therefore, the benefits of radiation use should be considered at the individual level through a balanced interpretation. Further low-dose radiation studies are essential to accurately determining the benefits and risks of radiation.

Field Map Estimation for Effective Fat Quantification at High Field MRI (고자장 자기공명영상에서 효율적인 지방 정량화를 위한 필드 맵 측정 기술)

  • Eun, Sung-Jong;Whangbo, Taeg-Keun
    • The Journal of the Korea Contents Association
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    • v.14 no.11
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    • pp.558-574
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    • 2014
  • The number of fatty liver patients is sharply growing due to the rapid increase in the incidence of metabolic syndrome, which can lead to diseases such as abdominal obesity, hypertension, diabetes, and hyperlipidemia. Early diagnosis requires examinations using magnetic resonance imaging (MRI), wherein quantitative analyses are implemented through a professional water-fat separation method in many cases, as the intensity values of the areas of interest and non-interest are considerably similar or the same. However, such separation method generates inaccurate results in high magnetic fields, where the inhomogeneity of the fields increases. To overcome the limits of such conventional fat quantification methods, this paper proposes a field map estimation method that is effective in high magnetic fields. This method generates field maps through echo images that are obtained using the existing IDEAL sequences, and considers the wrapping degree of the field maps. Then clustering is performed to separate calibration areas, the least square fits based on the region growing method schema of the separated calibration areas, and the histograms are adjusted to separate the water from the fats. In experiment results, our proposed method had a superior fat detection rate of an average of 86.4%, compared to the ideal method with an average of 61.5% and Yu's method with an average of 62.6%. In addition, it was confirmed that the proposed method had a more accurate water detection rate of 98.4% on the average than the 88.6% average of the fat saturation method.

Clinicopathologic and Epidemiologic Study of Childhood Nephrotic Syndrome in Taejon, Korea (대전지역 소아 신증후군의 임상병리학적 및 역학적 연구)

  • Yim Sam-Hwa;Yoon Kye-Nam;Cha Sang-Won;Lee Dong-Joon;Han Ji-Whan;Whang Kyung-Tae;Lee Kyung-Yil
    • Childhood Kidney Diseases
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    • v.3 no.2
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    • pp.145-152
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    • 1999
  • Purpose: The prevalence of childhood renal diseases including the nephrotic syndrome in Korea has not been well established. In priority to this point, we analyzed ninety-six nephrotic children of the annual incidence, the ratio of them to all inpatients and estimated incidence of childhood nephrotic syndrome under 15 years of age in Taejon, Korea. Also we classified them by clinical and histopathological findings. Methods: we analyzed the admission and outpatient records retrospectively between June 1986 and December 1998. For the estimation of incidence, we were assisted with three other general hospitals in Taejon Results: The mean annual number and the ratio to inpatients were $7.4{\pm}2.1,\;0.3{\pm}0.11%$ respectively. The latter showed a tendency to decrease during the recent three years. The estimated annual incidences of childhood nephrotic syndrome in Taejon were 5.6 in 1988, 5.5 in 1993 and 4.8 in 1998 per 100,000 for children aged up to 15 years. The mean age of our patients was $6.8{\pm}3.5$ tears, 1-7 years of age was 55 cases(57.3%), and male to female ratio was 3.6:1. By the clinicopathologic classification, 89 cases(92.7%) were classified as primary nephrotic syndrome, and 7 cases(7.3%) as secondary nephrotic syndrome. Among the primary nephrotic syndrome, there was 79.8% of minimal change nephrotic syndrome, focal segmental glomerulosclerosis 11.2%, mesangial proliferation 4.5%, membranoproliferative glomerulonephritis 3.4%, and membranous nephropathy 1.1%. $Henoch-Sch\"{o}nlein$ nephritis was the most frequent of 3 cases in the secondary nephrotic syndrome. Respones to steroid therapy of 71 cases minimal change were classified as non-relapse 22.5%, non-frequent relapse 49.3%, frequent relapse 18.3% and steroid-dependence 9.9%. Conclusion: The estimated incidence of childhood nephrotic syndrome was about 5 per 100,000 for children aged up to 15 years and it showed little changes during 10 years in Taejon, Korea. Our results of clinicopathologic study was little difference from the results reported in other literatures.

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Seroepidemiologic Study of Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) Infection among Koreans in Rural Area, Korea (농촌지역의 B형, C형 간염에 관한 혈청역학적 연구)

  • Shin, Hai-Rim;Kim, Joon-Youn;Song, Jue-Bok;Suh, Byung-Seong;Kim, Jung-Man;Lee, Bu-Ok;Kim, Su-Yang;Ryang, Mu-Guan;Lee, Chae-Un;Chun, Jin-Ho;Yoo, Keun-Young;Ahn, Yoon-Ok
    • Journal of Preventive Medicine and Public Health
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    • v.30 no.1 s.56
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    • pp.17-29
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    • 1997
  • To estimate the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection and to determine associated risk factors, a population-based seroepidemiologic study was carried out. In 1993, a health examination survey of the population was carried out in rural area known to have a high incidence of liver cancer. The study population were those who volunteered to participate in a health survey over 10 years of age. Examinees were interviewed by specially trained staffs. Sera from 1,033 study subjects were tested for hepatitis B surface antigen (HBsAg) by .everse passive hemagglutinin (RPHA) estimation and for hepatitis C virus antibody (anti-HCV) by 2nd generation passive hemagglutinin (PHA) estimation. The age and sex standardized prevalence of HBsAg was 6.3% which was similar to national average, but that of anti-HCV was 5.1% which was 4 to 5 times higher than that of blood donors or other health examinees in Korea. In a multivariate analysis, transfusion history, surgical operative history, and acupuncture history were not associated with HBsAg positivity. In contrast, acupuncture history (adjusted odds ratio[OR]=2.2 : 95% Confidence interval[CI] 1.0-4.7) and surgical operative history(adjusted OR=2.0 : 95% CI 1.0-4.1) were associated with anti-HCV positivity. The present study suggest that there is an highly endemic area of HCV infection in Korea and probably this endemicity is associated with a parenteral source of HCV infection other than blood transfusion.

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GHG-AP Integrated Emission Inventories and Per Unit Emission in Biomass Burning Sector of Seoul (서울시 생물성 연소부문 온실가스-대기오염 통합 인벤토리 및 배출원단위분석)

  • Jung, Jaehyung;Kwon, O-Yul
    • Journal of Korean Society for Atmospheric Environment
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    • v.31 no.1
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    • pp.83-91
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    • 2015
  • Biomass burning is known to be one of the main sectors emitting greenhouse gases as well as air pollutants. Unfortunately, the inventory of biomass burning sector has not been established well. We estimated greenhouse gas (GHG) and air pollution (AP) integrated emissions from biomass burning sector in Seoul during year 2010. The data of GHG and AP emissions from biomass burning, classified into open burning, residential fireplace and wood stove, meat cooking, fires, and cremation, were obtained from Statistics Korea and Seoul City. Estimation methodologies and emission factors were gathered from reports and published literatures. Estimated GHG and AP integrated emissions during year 2010 were $3,867tonCO_{2eq}$, and 2,320 tonAP, respectively. Major sources of GHG were forest fires ($1,533tonCO_{2eq}$) and waste open burning ($1,466tonCO_{2eq}$), while those of AP were meat cooking (1,240 tonAP) and fire incidence (907 tonAP). Total emissions by administrative district in Seoul, representing similar patterns in both GHG and AP, indicated that Seocho-gu and Gangseo-gu were the largest emitters whereas Jung-gu was the smallest emitter, ranged in $2{\sim}165tonCO_{2eq}$ and 0.1~8.31 tonAP. GHG emissions per $km^2$ showed different results from total emissions in that Gwanak-gu, Jungnang-gu, Gangdong-gu and Seodaemun-gu were the largest emitters, while Seocho-gu and Gangseo-gu were near-averaged emission districts, ranged in $0.2{\sim}21tonCO_{2eq}/km^2$. However, AP emissions per $km^2$ revealed relatively minor differences among districts, ranged in $2.3{\sim}6.1tonAP/km^2$.

Evidence-based estimation of health care cost savings from the use of omega-3 supplementation among the elderly in Korea

  • Hwang, Ji-Yun;Kim, Wu Seon;Jeong, Sewon;Kwon, Oran
    • Nutrition Research and Practice
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    • v.9 no.4
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    • pp.400-403
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    • 2015
  • BACKGROUND/OBJECTIVES: By the year 2050, thirty-eight percent of the Korean population will be over the age of 65. Health care costs for Koreans over age 65 reached 15.4 trillion Korean won in 2011, accounting for a third of the total health care costs for the population. Chronic degenerative diseases, including coronary heart disease (CHD), drive long-term health care costs at an alarming annual rate. In the elderly population, loss of independence is one of the main reasons for this increase in health care costs. Korean heath policies place a high priority on the prevention of CHD because it is a major cause of morbidity and mortality. SUBJECTS/METHODS: This evidence-based study aims to the estimate potential health care cost savings resulting from the daily intake of omega-3 fatty acid supplementation. Potential cost savings associated with a reduced risk of CHD and the medical costs potentially avoided through risk reduction, including hospitalizations and physician services, were estimated using a Congressional Budget Office cost accounting methodology. RESULTS: The estimate of the seven-year (2005-2011) net savings in medical costs resulting from a reduction in the incidence of CHD among the elderly population through the daily use of omega-3 fatty acids was approximately 210 billion Korean won. Approximately 92,997 hospitalizations due to CHD could be avoided over the seven years. CONCLUSIONS: Our findings suggest that omega-3 supplementation in older individuals may yield substantial cost-savings by reducing the risk of CHD. It should be noted that additional health and cost benefits need to be revisited and re-evaluated as more is known about possible data sources or as new data become available.

Rainfall analysis considering watershed characteristics and temporal-spatial characteristics of heavy rainfall (집중호우의 시·공간적 특성과 유역특성을 고려한 강우분석 연구)

  • Kim, Min-Seok;Choi, Ji-Hyeok;Moon, Young-Il
    • Journal of Korea Water Resources Association
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    • v.51 no.8
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    • pp.739-745
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    • 2018
  • Recently, the incidence of heavy rainfall is increasing. Therefore, a rainfall analysis should be performed considering increasing frequency. The current rainfall analysis for hydrologic design use the hourly rainfall data of ASOS with a density of 36 km on the Korean Peninsula. Therefore, medium and small scale watershed included Thiessen network at the same rainfall point are analyzed with the same design rainfall and time distribution. This causes problem that the watershed characteristics can not be considered. In addition, there is a problem that the temporal-spatial change of the heavy rainfall occurring in the range of 10~20 km can not be considered. In this study, Author estimated design rainfall considering heavy rainfall using minutely rainfall data of AWS, which are relatively dense than ASOS. Also, author analyzed the time distribution and runoff of each case to estimate the huff's method suitable for the watershed. The research result will contribute to the estimation of the design hydrologic data considering the heavy rainfall and watershed characteristics.

Improving the Performance of the Capon Algorithm by Nulling Elements of an Inverse Covariance Matrix (공분산 역행렬 원소 제거 기법을 이용한 Capon 알고리듬의 성능 개선)

  • Kim, Seong-Min;Kang, Dong-Hoon;Lee, Yong-Wook;Nah, Sun-Phil;Oh, Wang-Rok
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.48 no.5
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    • pp.96-101
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    • 2011
  • It is well known that the Capon algorithm offers better resolution compared to that of the FM (Fourier method) algorithm by minimizing the total output power while maintaining a constant gain in the look direction. Unfortunately, the DoA (Direction of Arrival) estimation performance of the Capon algorithm is drastically degraded when the SNR of received signal is low and thus, it cannot distinguish among signal sources which have similar incidence angles. In this paper, we propose a novel scheme enhancing the resolution of the Capon algorithm by ing all rows except the first row of an inverse covariance matrix.