• Economic Analysis
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• v.26 no.3
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• pp.48-70
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• 2020

Using data from the Household Income and Expenditure Survey over the period 1994-2016, we estimate the coefficient of relative prudence in order to capture precautionary saving motive. To do this, we adopt a cohort approach, where we transform such microdata into sample cohort means. Together with initial income involving liquidity constraint, we estimate the relative prudence derived from the Euler equation. The two-stage least-squares (2SLS) between estimate of it obtained from the cohort panel data analysis is too small for the existence of precautionary saving motive, as in previous studies, while the 2SLS random effects estimate is so reasonable. Moreover, the liquidity-constrained cohorts tend to be more sensitive to uncertainty, relative to the unconstrained ones.

• Journal of Yeungnam Medical Science
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• v.41 no.1
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• pp.39-44
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• 2024

Background: Medication-related osteonecrosis of the jaw (MRONJ) is a significant concern, particularly among patients taking bisphosphonates (BPs), denosumab, and selective estrogen receptor modulators (SERMs) for osteoporosis. Despite the known risks, large-scale cohort studies examining the incidence and severity of MRONJ are lacking. We aimed to ascertain the incidence and risk of MRONJ among these patients, whom we stratified by age groups, medication types, and duration of use. Methods: We utilized data from the National Health Insurance Service's sample cohort database, focusing on patients aged 40 years and above diagnosed with osteoporosis. The patients were divided into three groups: those prescribed BPs only, those prescribed SERMs only, and those prescribed both. Results: The overall incidence rate of MRONJ was 0.17%. A significantly higher incidence rate was observed among those taking osteoporosis medications, particularly among females with a relative risk of 4.99 (95% confidence interval, 3.21-7.74). The SERM group also had an incidence rate comparable to that of the BP group. Severity was assessed based on the invasiveness of the treatment methods, with 71.3% undergoing invasive treatment in the medication group. Conclusion: This study provides valuable insights into the incidence and severity of MRONJ among a large cohort of patients with osteoporosis. It underscores the need for comprehensive guidance on MRONJ risks across different medication groups and sets the stage for future research focusing on specific populations and treatment outcomes.

• BioChip Journal
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• v.12 no.4
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• pp.304-308
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• 2018

Atopic disease is caused by a complex combination of environmental factors and genetic factors, and studies on influence of exposure to various environmental factors on atopic diseases are continuously reported. However, the exact cause of atopic dermatitis is not yet known. Our study was conducted to analyse the association of SNPs with the development of atopic disease in a small cohort. Samples were collected from the Mothers' and Children's Environmental Health (MOCEH) study and 192 cord blood DNA samples were used to identify incidence of atopy due to influence of exposure to environmental factors. Genetic elements were analysed using a precision medicine research (PMR) array designed with various SNPs for personalized medicine. Case-control analysis of atopy disease revealed 253 significant variants (p<0.0001) and SNPs on five genes (CARD11, ZNF365, KIF3A, DMRTA1, and SFMBT1) were variants identified in previous atopic studies. These results are important to confirm the genetic mutation that may lead to the onset of foetal atopy due to maternal exposure to harmful environmental factors. Our results also suggest that a small-scale genome-wide association analysis is beneficial to confirm specific variants as direct factors in the development of atopy.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.48 no.5
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• pp.259-266
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• 2022

The relationship between obstructive sleep apnea (OSA) and diverse types of pain conditions have been proposed. However, no consensus on the relationship between OSA and painful temporomandibular disorders (TMDs) has been established. Therefore, this systematic review has been conducted to review the existing literatures and provide comprehensive synthesis of such literatures about OSA and painful TMDs using the evidence-based methodology. A literature search was conducted using two electronic databases, Scopus, and PubMed. Risk of bias was assessed using the risk-of-bias assessment tool for non-randomized study version 2.0. A total of 158 articles were screened from the initial search and eventually, 5 articles were included in this systematic review. One study adopted both the longitudinal prospective cohort and case-control designs and other 4 articles adopted the cross-sectional design. Two studies employed polysomnography (PSG) for the diagnosis of OSA and mentioned the results from the PSG. All cross-sectional studies demonstrated higher OSA prevalence among patients with TMD, and one cohort study suggested OSA as a risk factor for TMD. OSA appears to have potential influences on the development of TMD; however, the role of TMD in the development of OSA remains to be unknown owing to the lack of high-quality evidences.

• Clinical and Experimental Pediatrics
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• v.65 no.3
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• pp.131-135
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• 2022

Purpose: There is inconsistent evidence about the association between fetal nuchal cord and the risk of autism spectrum disorder (ASD). We performed a meta-analysis to investigate whether fetal nuchal cord is associated with an increased risk of ASD in offspring. Methods: Three main English databases were searched until January 2021. The Newcastle-Ottawa Scale was used to assess study quality. Study heterogeneity was determined using the I 2 statistic, while publication bias was assessed using Begg and Egger tests. Results are presented as odds ratios (ORs) and relative ratios with 95% confidence intervals (CI) and were determined by a random-effects model. Results: Five articles (1 cohort, 4 case-control; 3,088 total children) were included in the present meta-analysis. Fetal nuchal cord was not a risk factor for ASD (OR, 1.11; 95% CI, 0.66-1.57). There was homogeneity among studies that reported a risk of ASD (I²=0.0%). Conclusion: Our results showed that fetal nuchal cord is not a risk factor for ASD. Future large cohort studies should confirm this finding.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.3
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• pp.193-200
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• 2020

Purpose: To investigate the relationship between dementia and complete tooth loss on both sides or one side using large demographic data. Materials and methods: A retrospective cohort study was designed using the National Health Insurance Service-Elderly Cohort Database (NHIS-ECD) which was established for people over the age of 60. The experimental group was the complete edentulous cohort, which had a history of treatment for national health insurance covered complete denture on both sides or one side from July 1, 2012 to December 31, 2013. And the control group was the dentulous cohort, which had a history of conservative dental treatment for the same period. All subjects had no history of diagnosis or treatment of dementia during this time. These cohorts were matched 1:1 by age, gender, and place of residence according to the propensity score matching method. Then the incidence of dementia was compared between these cohorts. Results: Compared with those groups, the incidence of dementia was significantly higher in the experimental group (12.13%) than in the control group (9.74%) (P<.05). No clear association between other factors has been identified. Conclusion: The analysis of large-scale demographic data shows that the incidence of dementia is high in complete edentulous patients on both sides or one side.

• 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.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.7
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• pp.3143-3147
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• 2012

Background: Previous studies investigating the association of physical activity with risk of lung cancer reported conflicting results. In order to update and improve available evidence on any link, a meta-analysis was performed. Method: We searched the PubMed database for prospective cohort studies investigating the relation of physical activity with risk of lung cancer. The pooled relative risk (RR) with its 95% confidence intervals (95%CI) was used to assess the association. Results: We included 14 prospective studies with a total of 1,644,305 participants, with 14,074 incident lung cancer cases documented during follow-up. Meta-analysis of all 14 studies suggested both high and medium levels of physical activity to be associated with decreased risk of lung cancer compared to the reference group with low level of physical activity (for high level, RR = 0.77, 95%CI 0.73-0.81, P < 0.001; for medium level, RR = 0.87, 95%CI 0.83-0.90, P < 0.001). Subgroup analyses by gender found obvious associations in both men and women. No publication bias was observed. Conclusion: Our findings suggest that high and medium levels of physical activity have a beneficial effect on lung cancer by reducing the overall risk of tumour development among both men and women.

• Journal of Preventive Medicine and Public Health
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• v.36 no.3
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• pp.213-222
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• 2003

Genomic epidemiology is defined as 'an evoking field of inquiring that uses the systematic application of epidemiologic methods are approaches in population-based studies of the impact of human genetic variation on health and disease (Khoury, 1998)'. Most human diseases are caused by the intricate interaction among environmental exposures and genetic susceptibility factors. Susceptibility genes involved in disease pathogenesis are categorized into two groups: high penetrance genes (i.e., BRAC1, RB, etc.) and lour penetranoe genes (i.e., GSTs, Cyps, XRCC1, ets.), and low penetrance susceptibility genes has the higher priority for epidemiological research due to high population attributable risk. In this paper, the summarized results of the association study between single nucleotide polymorphisms (SNPs) and breast cancer in Korea were introduced and the international trends of genomic epidemiology research were reviewed with an emphasis on internee-based case-control and cohort consortium.

• Proceedings of the Korean Statistical Society Conference
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• 2004.11a
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• pp.243-248
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• 2004

The timings of two successive events of interest may not be measurable, instead it may be right censored or interval censored; this data structure is called doubly censored data. In the study of HIV, two such events are the infection with HIV and the onset of AIDS. These data have been analyzed by authors under the assumption that infection time and induction time are independent. This paper investigates the regression problem when two events arc modeled to allow the presence of a possible relation between two events as well as a subject-specific effect. We derive the estimation procedure based on Goetghebeur and Ryan's (2000) piecewise exponential model and Gauss-Hermite integration is applied in the EM algorithm. Simulation studies are performed to investigate the small-sample properties and the method is applied to a set of doubly censored data from an AIDS cohort study.