• Journal of Korean Dental Science
• /
• 제12권2호
• /
• pp.48-57
• /
• 2019

Purpose: To investigate whether there are specific surgical or clinical conditions where the use of autogenous bone (AB) is superior to the use of bone substitutes (BSs) for maxillary sinus floor augmentation (MSFA). Materials and Methods: We retrospectively analyzed 386 implants after MSFA in 178 patients. The implants were divided into five groups according to the sinus graft material used. Risk factors for implant failure in MSFA, and correlation between residual bone height (RBH) and graft materials in terms of implant survival were investigated. To investigate risk factors for implant failure in MSFA, implant survival according to graft materials, patients' sex/age, surgical site, RBH, healing period prior to prosthetic loading, staged- or simultaneous implantation with MSFA, the crown-to-implant ratio, prosthetic type, implant diameter, and opposite dentition were evaluated. Result: The cumulative 2- and 5-year survival rates of implants placed in the grafted sinus (independent of the graft material used) were 98.7% and 97.3%, respectively. None of the investigated variables were identified as significant risk factors for implant failure. There was also no statistical significance in implant survival between graft materials. Conclusion: There were no specific surgical conditions in which AB was superior to BSs in terms of implant survival after MSFA.

• Journal of the Korean Data and Information Science Society
• /
• 제27권2호
• /
• pp.477-486
• /
• 2016

본 연구의 목적은 한국의 제2형 성인 당뇨병 환자를 대상으로 당뇨병 위험 지각 측정 도구 (RPS-DM)의 신뢰도와 타당도를 평가하기 위하여 시도되었다. 당뇨병 위험 지각 측정 도구는 번역 과정을 통해 내용타당도를 확보한 후 서울 지역 상급 종합병원 내분비내과 외래를 이용하고 있는 성인 183명을 대상으로 자기입식 설문조사로 방식을 이용하여 자료 수집을 진행하였다. 자료 분석은 탐색적 요인분석과 문항 간 상관계수, 검사 재검사 신뢰도 검사를 수행하였다. 내용 타당도 검증 결과를 보면 당뇨병 위험 측정 도구는 '위험 지식'을 제외하면 '지각된 통제 (3문항)', '낙관적 편견 (2문항)', '환경적 위험 (9문항)', '질병 위험 (9문항)'의 4가지 하부 구성요인으로 확인되었으며, 4가지 요인으로 전체 분산의 45.1%를 설명하고 있었다. 원 도구에서 제시된 '걱정'은 위험 지각 측정 도구의 하부 구성 영역에서 제외하였다. 당뇨병 위험 측정 도구는 한국인의 당뇨병 위험 지각 수준을 측정할 수 있는 타당성있고 신뢰성이 있는 도구임을 제언한다.

• 보건행정학회지
• /
• 제18권4호
• /
• pp.49-65
• /
• 2008

The single-item question of self-assessed health status has consistently been reported to be associated with mortality in some developed countries, even after controlling for a wide range of health measurements and known risk factors for. mortality. It was intended in this study to find out whether or not such a relationship would also be valid in Korea. This study examined the effect of point of reference year on. the, predictive validity of self-assessed health for mortality in 6-year follow-up period. we need to test the validity of the self-assessed health, as an indicator for assessing health status using Cox's proportional hazard model. For the analysis, we used the data from the 2nd (1999) to the 7th survey of "Korean Labor and Income Panel Study," and assessed relative risk of death based on subjective health state by tracing 11,366 people who replied to the question of self-assessed health state in the 2nd year. According to the result, those who reported poor self assessed health state in the 2nd year showed a relatively high death rate, and their relative risk of death was significantly higher. Such a relationship was accentuated if the predictive value of the 2nd survey result would be replaced by the average of the cumulative data on the past six years. Thus, it can be concluded that self-assessed health state is valid as an index for assessing Korean people's health status.

• 대한골대사학회지
• /
• 제25권4호
• /
• pp.267-274
• /
• 2018

Background: This prospective cohort study used nationwide claims data to investigate the incidence of fall and fragility fractures in association with urinary incontinence (UI) in the elderly, and to compare mortality after fragility fractures in elderly patients with or without incontinence. Methods: A total of 39,854 Korean adults (age, 66-80 years) who participated in health examinations between 2007 and 2012 and were followed up until 2015 were analyzed. Patient and comparison groups were classified according to the presence or absence of UI. The cumulative incidence of osteoporotic fragility fractures and falls in the 2 groups was assessed and compared. Hazard ratios for fragility fractures were calculated for the risk of UI in association with falls using a Cox proportional hazards model. Results: Of 39,854 elderly participants, 5,703 were classified in the UI group, while 34,151 were placed in the comparison group. Fall rates were significantly higher (20.8%) in the incontinence group than in the comparison group (4.7%) (P<0.001). Women in the incontinence group (13.9%) showed a significantly higher incidence of all types of fragility fractures than those in the comparison group (11.8%) (P=0.005). After adjustment for confounders, UI was not a significant risk factor for fragility fractures in men (P=0.878) or women (P=0.324). Conclusions: This study demonstrated that elderly women with UI have a significantly higher incidence of osteoporotic fragility fractures. In addition, elderly women are at higher risk for falls.

• Journal of Chest Surgery
• /
• 제56권5호
• /
• pp.304-310
• /
• 2023

Background: The late progression of tricuspid regurgitation (TR) after mitral valve surgery is well known. However, few reports have described the progression of TR after aortic valve surgery. We investigated the incidence of and risk factors for the development of significant TR after isolated aortic valve replacement (AVR). Methods: This study analyzed patients with less than moderate TR who underwent isolated AVR at Seoul National University Hospital from January 1990 to December 2018. Significant TR was defined as moderate or higher. Echocardiographic follow-up was performed in all patients. The Fine-Gray model was used to identify clinical risk factors for the development of significant TR. Results: In total, 583 patients (61.7±14.2 years old) were included. Operative mortality occurred in 9 patients (1.5%), and the overall survival rates at 10, 20, and 25 years were 91.1%, 83.2%, and 78.9%, respectively. Sixteen patients (2.7%) developed significant TR during the follow-up period (13 moderate; 3 severe). The cumulative incidence of significant TR at 10, 20, and 25 years was 0.77%, 3.83%, and 6.42%, respectively. No patients underwent reoperation or reintervention of the tricuspid valve. Hemodialysis or peritoneal dialysis for chronic kidney disease (hazard ratio [HR], 5.188; 95% confidence interval [CI], 1.154-23.322) and preoperative mild TR (HR, 5.919; 95% CI, 2.059-17.017) were associated with the development of significant TR in the multivariable analysis. Conclusion: TR progression after isolated AVR in patients with less than moderate TR is rare. Preoperative mild TR and hemodialysis or peritoneal dialysis for chronic kidney disease were significant risk factors for the development of TR.

• 대한이식학회지
• /
• 제31권4호
• /
• pp.200-206
• /
• 2017

Background: Risk factors for bone avascular necrosis (AVN), a common late complication after kidney transplantation (KT), are not well known. Methods: Patients that underwent living-donor KT at Asan Medical Center between January 2009 and July 2016 were included in this retrospective study to determine the incidence and risk factors for AVN after KT. Results: Among 1,570 patients that underwent living-donor KT, 33 (2.1%) developed AVN during a mean follow-up of 49.8±25.0 months. Additionally, AVN was diagnosed at a mean of 13.9±6.6 months after KT. The mean cumulative corticosteroid dose during the last follow-up in patients without AVN (9,108±3,400 mg) was higher than that that in patients with AVN (4,483±1,114 mg) until AVN development (P<0.01). More patients among those with AVN (n=4, 12.1%) underwent steroid pulse treatment because of biopsy-proven rejections during the first 6 months after KT than patients without AVN (n=68, 4.4%; P=0.04). Female (hazard ratio [HR], 2.29; P=0.04) and steroid pulse treatment during the first 6 months (HR, 2.31; P=0.02) were significant AVN risk factors as revealed by the Cox proportional multivariate analysis. However, no significant differences in rejection-free graft survival rates were observed between the two groups (P=0.67). Conclusions: Steroid pulse treatment within 6 months of KT and being female were independent risk factors for AVN development.

• 대한교통학회지
• /
• 제17권5호
• /
• pp.33-42
• /
• 1999

본 논문은 도로투자 사업성분석시 사업주체의 현금흐름을 결정하는 항목들을 고정값(Deterministic Value)이 아닌 확률적으로 추정함으로써, 사업의 재무적 변동으로 인한 위험도를 민간사업자의 견지에서 사업성분석과정에 내재화하는 모형을 개발하는 것이다. 즉, 확률적 비용추정기법으로 국소적으로 활용되던 위험도분석을 재무모형에 내재화함으로써 사업의 재무적 변동을 보다 포괄적으로 분석할 수 있는 틀을 제공한다. 본 연구에서는 몬테카를로 시뮬레이션기법을 이용한 위험도분석(Risk Analysis)을 적용하여 사업성 평가지표와 비용의 확률밀도함수(Probability Density Function : PDF), 누적확률분포함수(Cumulative Distribution Function : CDF)를 산출하고, 그 결과로 해당 사업의 위험도를 고려하여 사업성을 평가한다. 이 모형은 사업의 모든 변동요인을 복합적으로 추정하여 사업기간 내 사업주체의 현금흐름을 분석할 수 있다. 따라서 사업주체는 효용에 따라 합리적인 위험도 관리 목표값(Target Value)을 선정하고, 사업의 위험도를 고려하여 건설비, 예비비를 결정할 수 있다. 본 연구에서 정립된 모형을 서울외곽순환고속도로(일산-퇴계원 구간)와 대전당진고속도로를 대상으로 사례분석을 수행하였다. 그 결과, 대전당진고속도로의 경우 사업성이 없으며, 서울외곽순환고속도로의 경우, 일부 위험도 발생변수를 합리적으로 관리한다면, 사업성이 충분한 것으로 분석되었다. 본 사례분석은 사업의 위험도를 반영한 사업성분석 방법으로 우리나라 민자유치대상고속도로의 사업성분석의 하나의 지침이 될 것이다.

• Environmental Analysis Health and Toxicology
• /
• 제16권2호
• /
• pp.43-50
• /
• 2001

A daily newspaper in Korea addressed an controversial issue recently that the concentration of radon measured from the groundwater in Taejon was found out a relatively high level. The cancer risk arising from ingestion of such radon should be derived from calculation of the dose absorbed by the tissues at risk. The study performed by the National Research Council in United States confirmed that the use of a PBPK model for the ingested radon could provide the useful information regarding the distribution of radon among the organs of the body. This study presents an approach for the internal dose assessment of ingested radon for this case. At first, the study develops a PBPK model for ingested radon. However, the important issue is how to simulate a more realistic situation using the model associated with repeated oral doses rather than a single oral dose. The simulations are performed for repeated oral exposures per 8-hour interval using the PBPK model for a male adult. The concentration and cumulative value of radon concentration are calculated and analyzed for lung tissue and adipose group, respectively. The results could be used for the realistic prediction of the internal dose of radon in the human body for repeated oral exposures.

• 대한인간공학회지
• /
• 제29권4호
• /
• pp.405-422
• /
• 2010

Occupational musculoskeletal disorders currently account for the largest proportion of the occupational illnesses in Korea. In this research, status of musculoskeletal disorders among the occupational illnesses was examined through workers' compensation claims data. Types and characteristics of musculoskeletal disorders were looked at other data set as well. The data sets included epidemiological investigation data reported by Occupational Safety and Health Research Institute, and data collected from occupational disease surveillance reports and Korean occupational health-related scientific journals. Number of cases, incidence rate and insurance benefits for occupational musculoskeletal disorders in Korea are increasing every year. In addition, musculoskeletal disorders occurrence is shifted from large enterprises group to small-and-medium group, from manufacturing to service sector, and from production workers to office and professional workers. Although low back pain is still most common, its occurrence characteristics is gradually shifted from traumatic to cumulative while musculoskeletal disorders are somewhat seemingly moved from lumbar to upper limb body part. Musculoskeletal disorders were observed to be more diverse and prevalent in epidemiological investigations or surveillance data rather in workers' compensation claims data. Musculoskeletal disorders occurrence is related to demographic factors, occupational psychosocial factors, and ergonomic risk factors at workplace for which appropriate preventive measures needed to be made accordingly.

• International Journal of Advanced Culture Technology
• /
• 제6권3호
• /
• pp.211-215
• /
• 2018

Ventilator-associated pneumonia (VAP) is a lung infection that develops in patients receiving mechanical ventilation. VAP contributes to about 50% of hospital-acquired pneumonia in ICU settings. One of the recommendation of the Institute of for Healthcare Improvement ventilator bundle is HOB elevation. HOB elevation affects shearing forces and makes higher risk for pressure injury development. Pressure injury (PI) is localized damage to the skin over a bony prominence. PI prevention guidelines recommend that HOB positioning should be lower to reduce risk for PI development which contradicts VAP prevention guidelines for the HOB between 30 and 45 degrees for ICU patients. This presents a care dilemma and tension. The purpose of this study was to perform a secondary data analysis using cumulative electronic health record data in order to determine the association of HOB elevation with VAP and PI in ICU patients. A secondary data analysis was conducted to determine whether HOB elevation is associated with VAP and PI. HOB elevation was not likely to be associated with VAP prevention whereas it was likely to be related to PI development. This is somewhat contrary to popular data and publications. Prospective cohort study is desired to inform us in an evidence-based fashion what actually is optimal HOB elevation for ventilated patients in ICU settings.