• Health Policy and Management
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• v.26 no.4
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• pp.359-372
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• 2016

Background: The purpose of this study was to develop risk-adjustment models for acute stroke mortality that were based on data from Health Insurance Review and Assessment Service (HIRA) dataset and to evaluate the validity of these models for comparing hospital performance. Methods: We identified prognostic factors of acute stroke mortality through literature review. On the basis of the avaliable data, the following factors was included in risk adjustment models: age, sex, stroke subtype, stroke severity, and comorbid conditions. Survey data in 2014 was used for development and 2012 dataset was analysed for validation. Prediction models of acute stroke mortality by stroke type were developed using logistic regression. Model performance was evaluated using C-statistics, $R^2$ values, and Hosmer-Lemeshow goodness-of-fit statistics. Results: We excluded some of the clinical factors such as mental status, vital sign, and lab finding from risk adjustment model because there is no avaliable data. The ischemic stroke model with age, sex, and stroke severity (categorical) showed good performance (C-statistic=0.881, Hosmer-Lemeshow test p=0.371). The hemorrhagic stroke model with age, sex, stroke subtype, and stroke severity (categorical) also showed good performance (C-statistic=0.867, Hosmer-Lemeshow test p=0.850). Conclusion: Among risk adjustment models we recommend the model including age, sex, stroke severity, and stroke subtype for HIRA assessment. However, this model may be inappropriate for comparing hospital performance due to several methodological weaknesses such as lack of clinical information, variations across hospitals in the coding of comorbidities, inability to discriminate between comorbidity and complication, missing of stroke severity, and small case number of hospitals. Therefore, further studies are needed to enhance the validity of the risk adjustment model of acute stroke mortality.

• 대한예방의학회:학술대회논문집
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• 2002.10a
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• pp.202-203
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• 2002

• The Korean Journal of Applied Statistics
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• v.17 no.3
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• pp.431-443
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• 2004

For the purpose of disease mapping, we consider the four small area estimation techniques to estimate the mortality rate of small areas; direct, Empirical estimation with total moment estimator and local moment estimator, Estimation based on hierarchial generalized linear model. The estimators are compared by empirical study based on lung cancer mortality data from 2000 Annual Reports on the Cause of Death Statistics in Gyeongsang-Do and Jeonla-Do published by Korean National Statistical Office. Also he stability and efficiency of these estimators are investigated in terms of mean square deviation as well as variation of estimates.

• Korea journal of population studies
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• v.3 no.1
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• pp.52-61
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• 1979

The purpose of the study is to construct a life table for population. It is based on the fraction of last year of life, $a_X$. The data necessary for this purpose have been obtained from the 1975 Population Census Report of Korea and the Vital Statistics of Shindong-myon, Chunseong-gun, Gangwon Province which is collected for the Seoul National University public health program. Age specific death rate is adapted by the Model Life Table, West, Level 21. For the age groups of less than 5 years of age, when the record of vital events can be obtained, the fractions are calculated from the community vital statistics. And for the age groups older than 5 years of age, Greville's Method is used. The findings are summarized as follows: 1) The fraction of last year of life in infantile group is 0.3684 for males, 0.3711 for females, and in 1-4 years of age group 1.2164 for males, 1.2274 for females. Both are more than those of Japan and U.S. in 1963. 2) Infant mortality rate is 42.37 for males, 31.77 for females per 1,000 live births. 3) The mortality curves show that a higher rate is observed under 1 year of age. It drops to the lowest point at around 10 years of age and rises again as the age increases. 4) The age estimated half-survival rate is during the age group of 70-74 for both sexes. 5) Life expectancy at the age of 0 shows 65.73 years for males and 69.22 years for females.

• Journal of Trauma and Injury
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• v.18 no.2
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• pp.141-147
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• 2005

Purpose: Recently, The new Injury Severity Score (NISS) has become a more accurate predictor of mortality than the traditional Injury Severity Score (ISS) in the trauma population. Trauma Score Injury Severity Score (TRISS) method, regarded as the gold standard for mortality prediction in trauma patients, still contains the ISS as an essential factor within its formula. The purpose of this study was to determine whether a simple modification of the TRISS by replacing the ISS with the NISS would improve the prediction of in-hospital mortality in a trauma population with blunt head and neck trauma. Objects and Methods: The study population consisted of 641 patients from a regional emergency medical center in Kyoungsangnam-do. Demographic data, clinical information, the final diagnosis, and the outcome for each patient were collected in a retrospective manner. the ISS, NISS, TRISS, and modified TRISS were calculated for each patients. The discrimination and the calibration of the ISS, NISS, modified TRISS and conventional TRISS models were compared using receiver operator characteristic (ROC) curves, areas under the ROC curve (AUC) and Hosmer-Lemeshow statistics. Results: The AUC of the ISS, NISS, modified TRISS, and conventional TRISS were 0.885, 0.941, 0.971, and 0.918 respectively. Statistical differences were found between the ISS and the NISS (p=0.008) and between the modified TRISS and the conventional TRISS (p=0.009). Hosmer-Lemeshow chi square values were 13.2, 2.3, 50.1, and 13.8, respectively; only the conventional TRISS failed to achieve the level of and an excellent calibration model (p<0.001). Conclusion: The modified TRISS is a more accurate predictor of in-hospital mortality than the conventional TRISS in a trauma population of blunt head and neck trauma.

• Journal of Preventive Medicine and Public Health
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• v.41 no.5
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• pp.300-306
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• 2008

Objectives : This study was performed to compare the standardized mortality ratios among different small areas and to explore the usefulness of standardized mortality ratios in South Korea. Methods : To calculate the standardized mortality ratio (SMR), we obtained the national deaths certificate data (2004-2006) and national registration population data (2003-2006), and these were provided by the National Statistical Office. The small areas (Eup.Myoun.Dong) were based on the subdivisions of counties. Among the 3,580 small areas classified by the National Statistical Office, 3,571 areas were included in this study. The basic statistics and decile distributions of the SMRs for all the regional levels were calculated, and the small area maps were also produced for some selected regions. To evaluate the precision of SMR, we calculated the 95% confidence intervals of the SMR in selected small areas. Results : The mean and the standard deviation of the SMRs among all small areas were 100.8 and 17.0, respectively. The range was 30.6-211.7 and the inter-quartile range was 20.7. Seoul metropolitan city displayed the lowest mean SMR among 16 regions in South Korea, and 34.6 percent of the small area SMRs belonged to the first decile(the lowest group). On the contrary, the mean SMR of Gyeongsangnam province was highest, and 26.1 percent of the small area SMRs belonged to the tenth decile(the highest group). In some areas, the precision of the SMR, which was calculated by the 95% confidence intervals, remained questionable, yet it was quite stable for almost areas. Conclusions : The standardized mortality ratios can be useful for allocating health resources at the small area level in Korea.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.5249-5255
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• 2013

Background: The purpose of this study was to develop a single measure of cancer burden (SMCB), which can prioritize cancer sites by considering incidence and mortality. Materials and Methods: Incidence data from 1999 to 2010 were obtained from the Korea Central Cancer Registry. Mortality data from 1999 to 2010 were obtained from Statistics Korea. The SMCB was developed by adding incidence and mortality scores. The respective scores were given such that incidence and mortality were classified by ten ranges of equal intervals. Results: According to the SMCB in 2010, stomach cancer ranked $1^{st}$ in males with 20 points, and colorectal cancer was $2^{nd}$ with 11 points. Breast cancer and thyroid cancer were joint $1^{st}$ with 11 points for females. The SMCB for females was less than that for males. The burden of stomach cancer was $1^{st}$ in males from 1999-2010. The incidences of lung cancer and liver cancer decreased, whereas thyroid cancer and colon cancer increased during the period. Breast cancer and thyroid cancer burden showed tendencies to increase in females. Comparison of SMCB with disability-adjusted life years (DALY) and socioeconomic costs in 2005 showed that the top five cancer sites were similar, but there were differences in the size of the cancer burden. Conclusions: The SMCB indicated that the burdens of stomach cancer in males and thyroid and breast cancers in females were large. The single measure showed an advantage, reflected as the equivalent dimensions of incidence and mortality, whereas DALY and economic costs showed tendencies to reflect premature death.

• Journal of Preventive Medicine and Public Health
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• v.46 no.1
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• pp.10-18
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• 2013

Objectives: We investigated the association between particulate matter less than $10{\mu}m$ in aerodynamic diameter ($PM_{10}$) exposure and non-accidental mortality in Asian populations by meta-analysis, using both time-series and case-crossover analysis. Methods: Among the 819 published studies searched from PubMed and EMBASE using key words related to $PM_{10}$ exposure and non-accidental mortality in Asian countries, 8 time-series and 4 case-crossover studies were selected for meta-analysis after exclusion by selection criteria. We obtained the relative risk (RR) and 95% confidence intervals (CI) of non-accidental mortality per $10{\mu}g/m^3$ increase of daily $PM_{10}$ from each study. We used Q statistics to test the heterogeneity of the results among the different studies and evaluated for publication bias using Begg funnel plot and Egger test. Results: Testing for heterogeneity showed significance (p<0.001); thus, we applied a random-effects model. RR (95% CI) per $10{\mu}g/m^3$ increase of daily $PM_{10}$ for both the time-series and case-crossover studies combined, time-series studies relative risk only, and case-crossover studies only, were 1.0047 (1.0033 to 1.0062), 1.0057 (1.0029 to 1.0086), and 1.0027 (1.0010 to 1.0043), respectively. The non-significant Egger test suggested that this analysis was not likely to have a publication bias. Conclusions: We found a significant positive association between $PM_{10}$ exposure and non-accidental mortality among Asian populations. Continued investigations are encouraged to contribute to the health impact assessment and public health management of air pollution in Asian countries.

• Journal of Preventive Medicine and Public Health
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• v.56 no.1
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• pp.31-40
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• 2023

Objectives: This study investigated the effect of cognitive impairment on the association between social network properties and mortality among older Korean adults. Methods: This study used data from the Korean Social Life, Health, and Aging Project. It obtained 814 older adults' complete network maps across an entire village in 2011-2012. Participants' deaths until December 31, 2020 were confirmed by cause-of-death statistics. A Cox proportional hazards model was used to assess the risks of poor social network properties (low degree centrality, perceived loneliness, social non-participation, group-level segregation, and lack of support) on mortality according to cognitive impairment. Results: In total, 675 participants (5510.4 person-years) were analyzed, excluding those with missing data and those whose deaths could not be verified. Along with cognitive impairment, all social network properties except loneliness were independently associated with mortality. When stratified by cognitive function, some variables indicating poor social relations had higher risks among older adults with cognitive impairment, with adjusted hazard ratios (HRs) of 2.12 (95% confidence interval [CI], 1.34 to 3.35) for social nonparticipation, 1.58 (95% CI, 0.94 to 2.65) for group-level segregation, and 3.44 (95% CI, 1.55 to 7.60) for lack of support. On the contrary, these effects were not observed among those with normal cognition, with adjusted HRs of 0.73 (95% CI, 0.31 to 1.71), 0.96 (95% CI, 0.42 to 2.21), and 0.95 (95% CI, 0.23 to 3.96), respectively. Conclusions: The effect of social network properties was more critical among the elderly with cognitive impairment. Older adults with poor cognitive function are particularly encouraged to participate in social activities to reduce the risk of mortality.

• Health Policy and Management
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• v.24 no.2
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• pp.143-152
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• 2014

Background: Previous studies showed that the characteristics of population and regions were related to the suicide rates. This study purposed to analyze the relationships between regional factors and suicide rates with spatial analysis model. Methods: This is a cross sectional study based on the statistics of 2011 which was extracted from the 229 City Gun Gu administrative districts in Korea. Cause of death statistics on each district was used to produce the age-, sex-adjusted mortality rates resulting from suicide. Regional characteristics were measured by the number of doctors engaged in medical institutions per 1,000 population, divorced people's rate per 1,000 population, number of marriages per 1,000 population, and percent of welfare budget in general accounting. Statistical analysis was performed by using SAS ver. 9.3 and ArcGIS ver. 10.2 was used for geographically weighted regression (GWR). Results: In ordinary least square (OLS) regression, divorced people's rate per 1,000 population had a significant positive relationship with the standardized mortality rate per 100,000 population. Marriages per 1,000 population and the proportion of welfare budget in the general accounting had significant negative relationships with the mortality rates. Meanwhile, GWR provided that the directions of variable, divorced people's rate per 1,000 population, were varied depending on regions. The adjusted $R^2$ was improved from the 0.32 in OLS to the 0.46 in GWR. Conclusion: Results of GWR showed that regional factors had different effects on the suicide rates depending on locations. It suggested that policy interventions for reducing the suicide rate should consider the regional characteristics in obtaining policy objectives.