Post Hotelling's T-square Procedure to Identify Fault Variables

10.1080/00949655.2023.2228958Journal of Statistical Computation and Simulation9411-2

A prediction model for childhood obesity risk using the machine learning method: a panel study on Korean children

Abstract Young children are increasingly exposed to an obesogenic environment through increased intake of processed food and decreased physical activity. Mothers’ perceptions of obesity and parenting styles influence children’s abilities to maintain a healthy weight. This study developed a prediction model for childhood obesity in 10-year-olds, and identify relevant risk factors using a machine learning method. Data on 1185 children and their mothers were obtained from the Korean National Panel Study. A prediction model for obesity was developed based on ten factors related to children (gender, eating habits, activity, and previous body mass index) and their mothers (education level, self-esteem, and body mass index). These factors were selected based on the least absolute shrinkage and selection operator. The prediction model was validated with an Area Under the Receiver Operator Characteristic Curve of 0.82 and an accuracy of 76%. Other than body mass index for both children and mothers, significant risk factors for childhood obesity were less physical activity among children and higher self-esteem among mothers. This study adds new evidence demonstrating that maternal self-esteem is related to children’s body mass index. Future studies are needed to develop effective strategies for screening young children at risk for obesity, along with their mothers

Prediction of typhoon-induced flood flows at ungauged catchments using simple regression and generalized estimating equation approaches

Typhoons are the main type of natural disaster in Korea, and accurately predicting typhoon-induced flood flows at gauged and ungauged locations remains an important challenge. Flood flows caused by six typhoons since 2002 (typhoons Rusa, Maemi, Nari, Dienmu, Kompasu and Bolaven) are modeled at the outlets of 24 Geum River catchments using the Probability Distributed Moisture model. The Monte Carlo Analysis Toolbox is applied with the Nash Sutcliffe Efficiency as the criterion for model parameter estimation. Linear regression relationships between the parameters of the Probability Distributed Moisture model and catchment characteristics are developed for the purpose of generalizing the parameter estimates to ungauged locations. These generalized parameter estimates are tested in terms of ability to predict the flood hydrographs over the 24 catchments using a leave-one-out validation approach. We then test the hypothesis that a more complex generalization approach, the Generalized Estimating Equation, which includes properties of the typhoons as well as catchment characteristics as predictors of PDM model parameters, will provide more accurate predictions. The results show that the predictions of Generalized Estimating Equation are comparable to those of the simpler, conventional regression. The simpler approach is therefore recommended for practical applications; however, further refinements of the Generalized Estimating Equation approach may be explored

Effect of metabolic health and obesity on all-cause death and CVD incidence in Korean adults: a retrospective cohort study

Abstract This study aimed to investigate the risk of all-cause mortality and incidence of CVD according to metabolic health and body mass index (BMI) in Korean adults. This study was retrospectively designed using the National Health Insurance Service-National Health Screening Cohort data. Participants were divided into six groups according to two category of metabolic syndrome and three categories of BMI. Hazard ratios (HRs) and 95% confidence intervals (CIs) for the composite outcome (all-cause mortality and incidence of CVDs) were estimated using multivariable Cox proportional hazards regression models. 151,706 participants aged ≥ 40 years were enrolled; median follow-up period was 9.7 years in the study. Compared to metabolically healthy normal weight, the fully adjusted HRs (95% CIs) of metabolically healthy overweight, metabolically healthy obese, metabolically unhealthy normal weight, metabolically unhealthy overweight, and metabolically unhealthy obese for composite outcome were 1.07 (1.03–1.12), 1.12 (1.07–1.17), 1.33 (1.25–1.41), 1.28 (1.22–1.34), and 1.31 (1.26–1.37), respectively, in men, and 1.10 (1.05–1.16), 1.22 (1.16–1.29), 1.34 (1.26–1.43), 1.27 (1.19–1.34), and, 1.40 (1.34–1.47), respectively, in women. High BMI and metabolic unhealthiness were associated with an increased risk on the composite of all-cause mortality and incidence of CVD in both sexes

Primary Prevention of Cardiocerebrovascular Diseases and Related Deaths According to Statin Type

(1) Background: Statin is the mainstay of treatment for the primary prevention of atherosclerotic cardiocerebrovascular diseases (CCVDs) in adults with hypercholesterolemia. This study aims to investigate the differences in effect on primary composite outcomes (CCVDs and CCVD-related deaths) among five statins in hypercholesterolemic individuals. (2) Methods: This retrospective study is based on the Korean National Health Insurance Service-National Health Screening Cohort. Participants, aged 40 to 69 years at baseline, were categorized into five statin-treated groups (pitavastatin, atorvastatin, rosuvastatin, simvastatin, and pravastatin) and two untreated groups (untreated hypercholesterolemia and no hypercholesterolemia). (3) Results: A total of 161,583 individuals was included. The median follow-up period was 8.2 years. Compared with the pitavastatin group, the hazard ratios (HRs; 95% confidence intervals (CIs)) for CCVDs and CCVD-related deaths of the atorvastatin, rosuvastatin, simvastatin, pravastatin, untreated hypercholesterolemia, and no-hypercholesterolemia groups were 0.969 (0.567–1.657), 0.988 (0.533–1.832), 0.862 (0.490–1.518), 0.906 (0.326–2.515), 2.665 (1.556–4.562), and 0.656 (0.388–1.110), respectively, in men and 1.124 (0.632–1.999), 1.119 (0.582–2.152), 1.324 (0.730–2.400), 1.023 (0.330–3.171), 2.650 (1.476–4.758), and 0.921 (0.522–1.625), respectively, in women, after being fully adjusted. (4) Conclusions: No significant differences among the five statins were observed, but there was an increased risk in untreated hypercholesterolemic individuals, for CCVDs and CCVDs-related deaths in individuals with hypercholesterolemia of either sex

Comparing different types of statins for secondary prevention of cardio-cerebrovascular disease from a national cohort study.

Statins have been recommended for use in atherosclerotic cardio-cerebrovascular disease (CCVD). The purpose of this study was to investigate the efficacy of five different types of statin in the secondary prevention of CCVD in patients. This study retrospectively designed and analyzed data from the National Health Insurance Service-National Health in Korea. Participants aged 40 to 69 years were categorized into five statin groups (atorvastatin, rosuvastatin, pitavastatin, simvastatin, and pravastatin). The primary composite outcome was defined as recurrence of CCVD or all causes of death. Cox proportional hazard regression models were adopted after stepwise adjustments for confounders to investigate the difference in efficacy among the different statins. Of the 755 final participants, 48 patients experienced primary composite outcomes. After adjustments, the hazard ratios (95% confidence intervals) for primary composite outcomes of atorvastatin, pitavastatin, and rosuvastatin groups were 0.956 (0.456-2.005), 1.347 (0.354-5.116), and 0.943 (0.317-2.803), respectively, when compared with the simvastatin group. There were no significant differences between the statins in efficacy for preventing recurrence of CCVD events and/or death in CCVD patients

Recent trends in opioid prescriptions in Korea from 2002 to 2015 based on the Korean NHIS-NSC cohort

OBJECTIVES Opioids are prescribed to treat moderate to severe pain. We investigated recent trends in opioid (morphine, oxycodone, fentanyl, and hydromorphone) prescriptions using data from the Korean National Health Insurance Service-National Sample Cohort between 2002 and 2015. METHODS The morphine milligram equivalent (MME) was calculated to standardize the relative potency of opioids. The number (cases) or amount (MME) of annual opioid prescriptions per 10,000 registrants was computed to analyze trends in opioid prescriptions after age standardization. Joinpoint regression analysis was conducted to calculate the annual percentage change and average annual percentage change (AAPC). RESULTS The number (cases) of prescriptions per 10,000 registrants increased from 0.07 in 2002 to 41.23 in 2015 (AAPC, 76.0%; 95% confidence interval [CI], 61.6 to 91.7). The MME per 10,000 registrants increased from 15.06 in 2002 to 40,727.80 in 2015 (AAPC, 103.0%; 95% CI, 78.2 to 131.3). The highest AAPC of prescriptions and MME per 10,000 registrants were observed in the elderly (60-69 years) and in patients treated at general hospitals. Fentanyl prescriptions increased most rapidly among the 4 opioids. CONCLUSIONS Consumption of opioids greatly increased in Korea over the 14-year study period

Diabetes, Metformin, and Lung Cancer: Retrospective Study of the Korean NHIS-HEALS Database

Background: Metformin is the first option in managing type 2 diabetes mellitus (DM) and has pleotropic effects. We studied the incidence of lung cancer in patients who received metformin therapy. Patients and Methods: This study was retrospectively designed and based on the Korean National Health Insurance Service–National Health Screening Cohort to determine whether metformin reduces lung cancer risk in the diabetic population. At baseline, all participants were 40 to 69 years old and were categorized into 3 groups: metformin nonrecipients with DM, metformin recipients with DM, and the nondiabetic group. Results: A total of 336,168 individuals were included in the final analysis (314,291 nondiabetic individuals, 8806 metformin recipients, and 13,071 metformin nonrecipients). The study median follow-up period was 12.86 years. The estimated cumulative lung cancer incidence of metformin nonrecipients, metformin recipients, and the nondiabetic group was 1.80%, 1.97%, and 1.24% in men and 1.87%, 0.61%, and 0.41% in women, respectively (P \u3c .05). Compared to metformin nonrecipients, the hazard ratios (95% confidence intervals) for lung cancer incidence of metformin recipients and the nondiabetic group were 1.287 (0.979-1.691) and 0.835 (0.684-1.019) in men and 0.664 (0.374-1.177) and 0.553 (0.359-0.890) in women, respectively. The hazard ratios (95% confidence intervals) were statistically significant in male ever smokers (0.784 [0.627-0.979]) and female nonsmokers (0.498 [0.320-0.774]) after stratification according to smoking status. Conclusion: Metformin therapy did not reduce lung cancer incidence in the diabetic population. However, individuals without DM were at a lower risk of lung cancer, especially in male ever smokers and female nonsmokers