• Journal of dental hygiene science
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• v.24 no.1
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• pp.22-28
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• 2024

Background: Particulate matter (PM) has been extensively observed due to its negative association with human health. Previous research revealed the possible negative effect of air pollutant exposure on oral health. However, the predictive model between air pollutant exposure and the prevalence of periodontitis has not been observed yet. Therefore, this study aims to propose a predictive model for the number of patients with periodontitis exposed to PM and atmospheric factors in South Korea using deep learning. Methods: This study is a retrospective cohort study utilizing secondary data from the Korean Statistical Information Service and the Health Insurance Review and Assessment database for air pollution and the number of patients with periodontitis, respectively. Data from 2015 to 2022 were collected and consolidated every month, organized by region. Following data matching and management, the deep neural networks (DNN) model was applied, and the mean absolute percentage error (MAPE) value was calculated to ensure the accuracy of the model. Results: As we evaluated the DNN model with MAPE, the multivariate model of air pollution including exposure to PM_2.5, PM₁₀, and other atmospheric factors predict approximately 85% of the number of patients with periodontitis. The MAPE value ranged from 12.85 to 17.10 (mean±standard deviation=14.12±1.30), indicating a commendable level of accuracy. Conclusion: In this study, the predictive model for the number of patients with periodontitis is developed based on air pollution, including exposure to PM_2.5, PM₁₀, and other atmospheric factors. Additionally, various relevant factors are incorporated into the developed predictive model to elucidate specific causal relationships. It is anticipated that future research will lead to the development of a more accurate model for predicting the number of patients with periodontitis.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2583-2589
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• 2013

Purpose: Studies have indicated that diabetes mellitus (DM) is a risk factor for bladder cancer; however, not all evidence supports this conclusion. The aim of this meta-analysis was to collate and evaluate all primary observational studies investigating the risk of bladder cancer associated with DM. Methods: The PubMed and Google Scholar databases were searched to identify studies that estimated the association of DM and bladder cancer. Summary effect estimates were derived using a random-effects meta-analysis model. Results: A total of 23 studies (8 case-control studies, 15 cohort studies) including 643,683 DM and 4,819,656 non-DM cases were identified. Analysis of all studies showed that DM was associated with an increased risk of bladder cancer compared with non-DM overall (OR=1.68, 95% CI 1.32-2.13). Analysis of subgroups demonstrated this to be the case in both case-control studies (OR=1.59, 95% CI 1.28-1.97, $I^2$=58%) and cohort studies (RR=1.70, 95% CI 1.23-2.33, $I^2$=96%). There was no gender difference in DM-associated bladder cancer risk. Bladder cancer risk was increased in Asia and the North America region, but not in Europe. Furthermore, DM-associated bladder cancer risk was obviously higher in Asia than North America and Europe or in those with Caucasian ethnicity. With extension of follow-up time, the bladder cancer risk was not increased for the patients with DM. Conclusions: This meta-analysis provided further evidence supporting theDM association with a significantly higher risk of bladder cancer obtained from observational studies.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2643-2647
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• 2013

Background: Despite anti-smoking campaigns, smoking prevalence among Thai males aged 30 or older is high, at around 50%. The purpose of this study was to determine the relationship between smoking and mortality in a rural Thai community. Materials and Methods: Subjects enrolled into the Khon Kaen cohort study between 1990 and 2001 were followed up for their vital status until $16^{th}$ March 2012. The death resource was from the Bureau of Policy and Strategy, Ministry of Interior, Thailand. A Cox proportional hazards model was used to analyse the association between smoking and death, controlling for age, education level and alcohol drinking, and confidence intervals were calculated using the floating risk method. Results: The study recruited 5,962 male subjects, of whom 1,396 died during a median 13.5 years of follow-up. Current smokers were more likely to die than never smokers after controlling for age, education level and alcohol drinking (HR, 95%CI: 1.41, 1.32-1.51), and the excess mortality was greatest for lung cancer (HR, 95%CI: 3.51, 2.65-4.66). However, there was no increased risk with increasing dose of tobacco, and no difference in risk between smokers of yamuan (hand-rolled cigarettes) and manufactured tobacco. Conclusion: Mortality from cancer, particularly lung cancer, and from all causes combined is dependent on smoking status among men in rural Thailand, but the relative risks are lower than have been reported from studies in high income countries, where the tobacco epidemic is more established.

• Journal of Preventive Medicine and Public Health
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• v.53 no.1
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• pp.37-44
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• 2020

Objectives: This study investigated the effects of comorbid sleep disorders (SD) on the incidence of cardiovascular complications among newly-diagnosed hypertension (HTN) patients. Methods: As study population, 124 057 newly-diagnosed essential HTN patients aged 30 or older, without cardiovascular complications at diagnosis with HTN, were selected from the National Health Insurance Service-National Sample Cohort. The incidence of cardiovascular complications was calculated, Cox proportional-hazards regression model was used to analyze the risk of complications, and the population attributable fraction (PAF) for cardiovascular complications of having comorbid SD at HTN diagnosis was calculated. Results: Over 10 years, 32 275 patients (26.0%) developed cardiovascular complications. In HTN patients with comorbid SD at diagnosis of HTN, the incidence of cardiovascular complications (78.3/1000 person-years; 95% confidence interval [CI], 75.8 to 80.9) was higher than in those without comorbid SD (58.6/1000 person-years; 95% CI, 57.9 to 59.3) and the risk of cardiovascular complications was 1.21 times higher (95% CI, 1.17 to 1.25), adjusting for age, gender, income, area of residence, and comorbid diabetes mellitus. The PAF of having comorbid SD at diagnosis of HTN for the incidence of cardiovascular complications was 2.07% (95% CI, 1.69 to 2.44). Conclusions: Newly-diagnosed essential HTN patients aged 30 or older who had comorbid SD at the time of their HTN diagnosis had a higher incidence of cardiovascular complications than those without comorbid SD. Age, gender, income, area of residence, and comorbid diabetes mellitus had a significant effect on the incidence of cardiovascular complications. Approximately 2% of cardiovascular complications were found to occur due to the presence of SD.

• Journal of Families and Better Life
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• v.26 no.1
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• pp.51-67
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• 2008

The study analyzes divorce rates in Korea and makes suggestions for the future research of divorce rates. Based on the data from Korea Statistical Information System (KOSIS) of the National Statistics Organization, trends for divorce rates change and the relations between divorce rates and macro environmental factors are analyzed. Macro environmental factors include socioeconomic factors such as, Korean War, Vietnam War, oil shock, IMP economic crisis and gross national income (GNI), whereas demographical factors include population structure, rates of female labor participation, and geographical location. The principle characteristics of divorce rates are as follows: 1) the Crude divorce rates (CDR) and the number of divorced had been increased from 1970 to 2004, then the trend changed to a decrease; 2) the slope of the change were the highest during 1998 to 2004 after the IMP economic crisis. The relations between socioeconomic factors are as follows: 1) during the war there was a small increase of CDR for a short period of time; 2) the economic crisis of the nation tend to increase the CDR, while the IMP economic crisis had a strong impact on an increase of CDR because of the interaction effect among the population structure, women's sex role changes as well as the level of standard of living. The increase in CDR from 1990 to 2000 can be explained partly by the population of baby Boomers passing through their marriage and divorce process. The number of population residing in the rural area and the middle class households, and the mobility of population also had an impact on the divorce rates changes. The recommendations for the future research were as follows: 1) the need to develop new divorce statistics that are based on a marriage cohort or a birth cohort because family behavior is a mixture of personal, social and political responses, and because CDR is not an accurate measure of divorce rate since it was influenced by population structure; 2) the need to include micro personal factors as well as macro social factors in a model to find an interaction effect between those variables.

• Journal of Preventive Medicine and Public Health
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• v.51 no.4
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• pp.205-212
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• 2018

Objectives: The main purpose of this study was to quantify the risk of mortality linked to various regimens of hypertonic peritoneal dialysis (PD) solution. Methods: A retrospective cohort study of patients using home-based PD was carried out. The prescribed regimen of glucose-based PD solution for all patients, determined on the basis of their individual conditions, was extracted from their medical chart records. The primary outcome was death. The treatment regimens were categorized into 3 groups according to the type of PD solution used: original PD (1.5% glucose), shuffle PD (1.5 and 2.5% glucose), and serialized PD (2.5 and 4.5% glucose). Multivariate analysis (using the Weibull model) was applied to comprehensively examine survival probabilities related to the explanatory variable, while adjusting for other potential confounders. Results: Of 300 consecutive patients, 38% died over a median follow-up time of 30 months (interquartile range: 15-46 months). Multivariate analysis showed that a treatment regimen with continued higher-strength PD solution (serialized PD) resulted in a lower survival rate than when the conventional strength solution was used (adjusted hazard ratio, 2.6; 95% confidence interval, 1.6 to 4.6, p<0.01). Five interrelated risk factors (age, length of time on PD, hemoglobin levels, albumin levels, and oliguria) were significant predictors contributing to the outcome. Conclusions: Frequent exposure to high levels of glucose PD solution significantly contributed to a 2-fold higher rate of death, especially when hypertonic glucose was prescribed continuously.

• The Korean Journal of Pain
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• v.28 no.4
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• pp.244-253
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• 2015

Background: Although circumcision for phimosis in children is a minor surgical procedure, it is followed by pain and carries the risk of increased postoperative anxiety. This study examined predictive factors of postoperative pain and anxiety in children undergoing circumcision. Methods: We conducted a prospective cohort study of children scheduled for elective circumcision. Circumcision was performed applying one of the following surgical techniques: sutureless prepuceplasty (SP), preputial plasty technique (PP), and conventional circumcision (CC). Demographics and base-line clinical characteristics were collected, and assessment of the level of preoperative anxiety was performed. Subsequently, a statistical model was designed in order to examine predictive factors of postoperative pain and postoperative anxiety. Assessment of postoperative pain was performed using the Faces Pain Scale (FPS). The Post Hospitalization Behavior Questionnaire study was used to assess negative behavioral manifestations. Results: A total of 301 children with a mean age of $7.56{\pm}2.61$ years were included in the study. Predictive factors of postoperative pain measured with the FPS included a) the type of surgical technique, b) the absence of siblings, and c) the presence of postoperative complications. Predictive factors of postoperative anxiety included a) the type of surgical technique, b) the level of education of mothers, c) the presence of preoperative anxiety, and d) a history of previous surgery. Conclusions: Although our study was not without its limitations, it expands current knowledge by adding new predictive factors of postoperative pain and postoperative anxiety. Clearly, further randomized controlled studies are needed to confirm its results.

• Safety and Health at Work
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• v.8 no.2
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• pp.130-142
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• 2017

Background: Osteoarthritis of the knee is considered to be related to knee straining activities at work. The objective of this review is to assess the exposure dose-response relation between kneeling or squatting, lifting, and climbing stairs at work, and knee osteoarthritis. Methods: We included cohort and case-control studies. For each study that reported enough data, we calculated the odds ratio (OR) per 5,000 hours of cumulative kneeling and per 100,000 kg of cumulative lifting. We pooled these incremental ORs in a random effects meta-analysis. Results: We included 15 studies (2 cohort and 13 case-control studies) of which nine assessed risks in more than two exposure categories. We considered all but one study at high risk of bias. The incremental OR per 5,000 hours of kneeling was 1.26 (95% confidence interval 1.17-1.35, 5 studies, moderate quality evidence) for a log-linear exposure dose-response model. For lifting, there was no exposure dose-response per 100,000 kg of lifetime lifting (OR 1.00, 95% confidence interval 1.00-1.01). For climbing, an exposure dose-response could not be calculated. Conclusion: There is moderate quality evidence that longer cumulative exposure to kneeling or squatting at work leads to a higher risk of osteoarthritis of the knee. For other exposure, there was no exposure dose-response or there were insufficient data to establish this. More reliable exposure measurements would increase the quality of the evidence.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.3
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• pp.1069-1072
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• 2015

Background: Colorectal cancer (CRC) is an important cause of mortality and morbidity in many communities worldwide. This population based study was conducted to assess determinants of colorectal mortality in Iranian patients. Materials and Methods: A cohort of 1,127 cases of confirmed colorectal cancer registered in a population based registry covering 10 referral hospital in Tehran, Iran, were followed for five years. Information about tumor characteristics, smoking status and family history were collected at base line and survival status were followed every six months by contacting patient or next of kin (if patients died during the follow-up). The cause of death for each case was validated by verbal autopsy and referring to patient medical records at the time of death. The data were analyzed by Stata software using univariate and multivariate analysis (Cox regression). In building the model a p value of less than 5% was considered as significant. Results: The age at diagnosis was $53.5{\pm}14$ years. Sixty one percent were male. Colorectal mortality among the patients was 96.9 person-years among men and 83 person-years among women. Seventy five percent of patients lived for 2.72 years, 50% for 5.83, and 25% for 13 years after the diagnosis of colorectal cancer. The age at diagnosis was significantly different between men and women (p<0.03). Higher tumor grade predicted higher death rate; the adjusted hazard ratios were 1.79 (95%CI, 0.88-3.61), 2.16 (95%CI, 1.07-4.37), and 3.1 (95%CI, 1.51-6.34) for grades II, III, and IV respectively when they were compared with grade I as reference. Ethnicity, marital status, family history of cancer, and smoking were related to survival with different degrees of magnitude. Conclusions: Among many factors related to survival among the colorectal patients, tumor grade and smoking showed the highest magnitudes of association.

• Journal of Preventive Medicine and Public Health
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• v.50 no.3
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• pp.165-176
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• 2017

Objectives: This study aimed to estimate the risk of bleeding following minor oral surgical procedures and uninterrupted aspirin therapy in high-risk patients or patients with existing chronic diseases compared to patients who did not use aspirin during minor oral surgery at a public hospital. Methods: This retrospective cohort study analyzed the data of 2912 patients, aged 20 years or older, who underwent 5251 minor oral surgical procedures at a district hospital in Thailand. The aspirin group was comprised of patients continuing aspirin therapy during oral surgery. The non-aspirin group (reference) included all those who did not use aspirin during surgery. Immediate and late-onset bleeding was evaluated in each procedure. The risk ratio of bleeding was estimated using a multilevel Poisson regression. Results: The overall cumulative incidence of immediate bleeding was 1.3% of total procedures. No late-onset bleeding was found. A significantly greater incidence of bleeding was found in the aspirin group (5.8% of procedures, p<0.001). After adjusting for covariates, a multilevel Poisson regression model estimated that the bleeding risk in the aspirin group was 4.5 times higher than that of the non-aspirin group (95% confidence interval, 2.0 to 10.0; p<0.001). However, all bleeding events were controlled by simple hemostatic measures. Conclusions: High-risk patients or patients with existing chronic diseases who continued aspirin therapy following minor oral surgery were at a higher risk of hemorrhage than general patients who had not used aspirin. Nonetheless, bleeding complications were not life-threatening and could be promptly managed by simple hemostatic measures. The procedures could therefore be provided with an awareness of increased bleeding risk, prepared hemostatic measures, and postoperative monitoring, without the need for discontinuing aspirin, which could lead to more serious complications.