• Communications for Statistical Applications and Methods
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• 제28권2호
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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).

• 응용통계연구
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• 제34권3호
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• pp.347-373
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• 2021

지난 50여 년 동안 우리나라의 사망률 감소 패턴에 대한 탐색적 연구에 의하면 연령별 사망률이 모든 연령에서 감소했지만, 특정한 사망률이 개선되고 있는 패턴은 연령과 기간에 따라 다르다는 것을 알 수 있다. 여자가 남자보다 사망률 개선이 뚜렷하고 특히 시간이 지나면서 특정그룹에서의 사망률 개선이 두드러짐에 따라 전반적으로 사망 시간 추세에 구조적인 변화가 존재함을 확인하였다. 이에 본 연구에서는 우리나라 여자 사망률 자료를 이용하여 미래 사망률 예측을 위해 코호트 효과를 고려한 다양한 확률적 사망률 모형을 살펴보았다. 또한 분석 결과를 바탕으로 2067년까지 연령별 사망률과 예측기대수명을 작성하고 통계청(KOSIS)에서 제공하는 장래 연령별 사망률과 기대수명과 비교하였다. 자료이용기간에 따라 최적의 모형이 상이하나 적합력과 예측력을 전반적으로 고려했을 때 우리나라 여자 사망률은 코호트 효과를 고려한 PLAT 모형이 적절하다 볼 수 있을 것이다.

• 한국물환경학회지
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• 제22권6호
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• pp.1075-1081
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• 2006

In this research, mortality rates of pathogen indicator microorganisms discharged from various point sources and diffuse sources in urban area were measured. Water samples were taken at domestic sewer, combined sewer overflow, effluent from a wastewater treatment plant, urban river, and sediment of an urban river. Mortality rates of indicator microorganisms in domestic sewer estimated by assuming the first order kinetics at $20^{\circ}C$ were as follows: total coliform = 0.092/day, fecal coliform = 0.185/day, E. coli = 0.252/day, and fecal streptococci = 0.281/day. Sensitivity of mortality rates of total coliform on temperature was estimated as $K_{temp}=K_{20}{\times}1.162^{(temp-20)}$ for the range of $10-20^{\circ}C$. Mortality rates due to sunlight were measured as 1.22-1.59/day while mortality rate due to settling for 40 min were estimated as $9.21{\times}10^3-20.0{\times}10^3/day$.

• Child Health Nursing Research
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• 제26권4호
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• pp.463-469
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• 2020

Reduction of the under-5 mortality rate is a target of the Sustainable Development Goals. Therefore, this study aimed to estimate under-5 child mortality rates in 52 low-migration countries using population data. The study utilized population data from the US Census Bureau from 1990 to 2015. The method involved first estimating mortality rates for countries with negligible net migration and then applying these rates to countries with matching mortality profiles, where it is reasonable to assume that migration is negligible for children under the age of 5 years. The highest child mortality was concentrated in the African region, followed by Asia and the Western region. However, steady progress in child mortality trends was concentrated in low-income countries. This simple method demonstrated that child mortality has significantly improved in high-income countries, followed by middle- and low-income countries. To reduce the under-5 mortality rates even further in these 52 countries, there is a need to accelerate equitable plans and policies related to child health to promote children's longevity and survival.

• Journal of Preventive Medicine and Public Health
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• 제40권1호
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• pp.29-35
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• 2007

Objectives : To assess whether the risk-adjusted in-hospital mortality rates for non-emergent and isolated coronary artery bypass graft surgery (CABG) patients exhibited a consistent trend from 2001 to 2003. Methods : The data used in this study came from CABG claims that were submitted to a Korean Health Insurance Review Agency (HIRA) in 2001, 2002, and 2003. Study datasets included data from 17 tertiary hospitals, which had at least 25 claims each year over 3 years. The inter-hospital differences in patients' risk-factors were identified and controlled in the risk-adjustment model. Actual and predicted mortality rates for each hospital were calculated in 2001, 2002, 2003, and 2001+2002, and were then examined to identify consistent rate patterns over time. Kappa analysis was applied to assess the agreements between rates. Results : Hospitals with lower-than-expected inpatient mortality rates showed more consistent rates than those with higher-than-expected mortality rates. The mortality rates that were calculated based on data obtained over multiple years had less variation among hospitals than rates based on single year data. Based on the Kappa score, the highest agreement was found when the rates were compared between the 2-year combined data (2001+2002) and 2003. Conclusions : Consistent patterns over 3 years were most evident for hospitals which had lower-than expected mortality rates. Policy makers can use this information to identify the degree of outcomes in hospitals and help motivate or channel the behaviors of providers.

• 한국병원경영학회지
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• 제25권4호
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• pp.1-12
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• 2020

During the COVID-19 pandemic, most of the western countries with advanced medical technology failed to contain coronavirus. This fact triggered our research question of what factors influence the clinical outcomes like infection rates and case mortality rates. This study aims to identify the determinants of COVID-19 related infection rates and case mortality rates. We considered three sets of independent variables: 1) socio-demographic characteristics; 2) cultural characteristics; 3) healthcare system characteristics. For the analysis, we created an international dataset from diverse sources like World Bank, Worldometers, Hofstede Insight, GHS index etc. The COVID-19 related statistics were retrieved from Aug. 1. Total cases are from 95 countries. We used hierarchical regression method to examine the linear relationship among variables. We found that obesity, uncertainty avoidance, hospital beds per 1,000 made a significant influence on the standardized COVID-19 infection rates. The countries with higher BMI score or higher uncertainty avoidance showed higher infection rates. The standardized COVID-19 infection rates were inversely related to hospital beds per 1,000. In the analysis on the standardized COVID-19 case mortality rates, we found that two cultural characteristics(e.g., individualism, uncertainty avoidance) showed statistically significant influence on the case mortality rates. The healthcare system characteristics did not show any statistically significant relationship with the case mortality rates. The cultural characteristics turn out to be significant factors influencing the clinical outcomes during COVID-19 pandemic. The results imply that the persuasive communication is important to trigger the public commitment to follow preventive measures. The strategy to keep the hospital surge capacity needs to be developed.

• Asian Pacific Journal of Cancer Prevention
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• 제13권6호
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• pp.2495-2502
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• 2012

Nasopharyngeal carcinoma (NPC) is a disease with distinct ethnic and geographic distribution. The incidence of NPC in Chinese residing in Asia has declined over the last few decades, but NPC mortality trends in the entire Chinese population over time have not been systematically evaluated. In this study, we examined NPC mortality at the national level in China between 1973-2005. Mortality rates were derived from the databases of national retrospective surveys on cancer mortality conducted in the periods of 1973-1975, 1990-1992, and 2004-2005, respectively. NPC was classified according to the International classification of diseases. Age-adjusted mortality rates were calculated by direct standardization according to the world standard population. Trends in rates were evaluated by age, gender, geographic areas, and socioeconomic status. From 1973 to 2005, there was a general trend of decrease in NPC mortality in China, with higher rates in the south on a downward trend in the north. The age-standardized NPC mortality rates were 2.60 per 100,000 in 1973-1975, 1.94 per 100,000 in 1990-1992, and 1.30 per 100,000 in 2004-2005, respectively. The trend was similar in both men and women, in both urban and rural areas, but the declining rates in females were more remarkable than in males. The mortality rates were higher for the age groups above 50 years than those less than 50 years of age, both showing downward trend over 30-year period. In summary, the overall NPC mortality has consistently decreased in China over the past three decades, particularly in women and in old adults.

• 대한골대사학회지
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• 제25권4호
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• pp.227-233
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• 2018

Background: Few studies have investigated the effects of sarcopenia on postoperative outcomes including mortality rates following surgery for osteoporotic hip fractures. The purpose of the present study was to determine the prevalence of sarcopenia and the relationship between sarcopenia and 1- and 5-year mortality rates in a consecutive series of patients with osteoporotic hip fractures. Methods: Among patients who underwent hip surgery for osteoporotic hip fractures, this study included 91 patients subjected to abdominal computed tomography within 1 year of hip surgery. We defined sarcopenia using sex-specific cut-off points for the skeletal muscle index at the level of the third lumbar vertebra. All patients were divided into 2 groups according to the presence or absence of sarcopenia and the 1- and 5-year mortality rates were compared. To confirm factors affecting mortality in addition to sarcopenia, we examined patient age, sex, American Society of Anesthesiologists grade, location of fracture, type of surgery, and bone mineral density. Results: The 1- and 5-year mortality rates were 20.9% and 67.2%, respectively. Among the 45 patients with sarcopenia, the 1- and 5-year mortality rates were 22.2% and 82.7%, respectively. Of the 46 patients without sarcopenia, the 1- and 5-year mortality rates were 19.6% and 52.7%, respectively. Results of the Kaplan-Meier analysis showed that sarcopenia did not affect the 1-year mortality rate (P=0.793), but had a significant effect on the 5-year mortality rate (P=0.028). Both perioperative sarcopenia (P=0.018) and osteoporosis (P=0.000) affected the 5-year mortality rate. Conclusions: Sarcopenia increases the risk of 5-year mortality in patients with osteoporotic hip fractures.

• 보건행정학회지
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• 제17권3호
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• pp.87-105
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• 2007

The purpose of this study was to analyze whether nonemergency, isolated coronary artery bypass graft (CABG) surgery for high- or low-risk patients biases the assessment of the risk-adjusted mortality rates of hospitals. This study used 2002 National Health Insurance claims data for tertiary hospitals in Korea. The study sample consisted of 1,959 patients from 23 tertiary hospitals. The risk-adjustment model used the patients' biological, admission, and comorbidity data identified in the claims. The subjects were classified into high- and low-risk groups based on predicted surgical risk. The crude mortality rates and risk-adjusted mortality rates for low-risk, high-risk, and all patients in a hospital were compared based on the rank and the four intervals defined by quartile. Also, the crude mortality rates of the three groups were compared with their 95% confidence intervals of predicted mortality rates. The C-statistic (0.83) and Hosmer-Lemeshow test ($X^2$=11.47, p=0.18) indicated that the risk-adjustment model performed well. Presenting crude mortality rates with their 95% confidence intervals of predicted rates showed higher agreements among the three groups than using the rank or intervals of mortality rates defined by quartile in the hospital performance assessment. The crude mortality rates for the low-risk patients in 21 of the 23 hospitals were located on the same side of their 95% confidence intervals compared to that for all patients. High-risk patients and all patients differed at only one hospital. In conclusion, the impact of risk selection by hospital on the assessment results was the smallest when comparing the crude inpatient mortality rates of CABG patients with the 95% confidence intervals of predicted mortality rates. Given the increasing importance of quality improvements in Korean health policy, it will be necessary to use the appropriate method of releasing the hospital performance data to the public to minimize any unwanted impact such as risk-based hospital selection.

• 대한응급의학회지
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• 제29권5호
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• pp.474-484
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• 2018

Objective: The time to positivity (TTP) of blood culture reflects bacterial load and has been reported to be associated with outcome in bloodstream infections. This study was performed to evaluate the relationship between the TTP of blood culture and the mortality rates associated with sepsis and septic shock according to the site of infection. Methods: We performed a retrospective cohort study on patients with sepsis and septic shock. The rates of blood culture positivity and mortality as well as the relationship between the TTP and 28-day mortality rate were compared among patients with different sites of infection, such as the lungs, abdomen, urogenital tract, and other sites. Results: A total of 2,668 patients were included, and the overall mortality rate was 21.6%. The rates of blood culture positivity and mortality were different among the different infection sites. There was no relationship between the TTP and mortality rates of total, lung, and urogenital infections. Patients with abdominal infections showed a negative correlation between the TTP and 28-day mortality rate. In patients with abdominal infections, a TTP<20 hours was independently associated with 28-day mortality compared with patients with negative blood culture (hazard ratio, 1.73; 95% confidence interval, 1.16-2.58). However, there was no difference in mortality rates of patients with a $TTP{\geq}20$ hours and a negative blood culture. Conclusion: The shorter TTP in patients with abdominal infections in sepsis and septic shock was associated with a higher 28-day mortality rate.