• 대한지역사회영양학회지
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• 제25권6호
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• pp.512-519
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• 2020

Objectives: A cross-sectional study was conducted to investigate the associations between food groups and hearing loss. Methods: Data of 1,312 individuals were used from the Korea National Health and Nutrition Examination Survey 2013. Hearing loss was determined with a pure tone average (PTA) of greater than 25 dB in either ear. The PTA was measured as the average hearing threshold at speech frequencies of 0.5, 1, 2, and 4 kHz. The dietary intake was examined with a food frequency questionnaire with 112 food items. The food items were classified into 25 food groups. A weighted logistic regression was used to investigate the association. Results: Individuals in the highest tertile of vegetables and nuts food groups were less likely to have hearing loss than those in the lowest tertile [Odds Ratio (OR) = 0.58 (95% Confidence interval (CI) 0.38-0.91), P = 0.019; OR = 0.59 (95% CI 0.39-0.90), P = 0.020, respectively], after adjusting for confounding variables of age, sex, body mass index, drinking, smoking, diabetes, hypertension, and physical activity. Conclusions: In this cross-sectional study, we observed that high intake of vegetables and nuts food groups revealed significant inverse associations with hearing loss, after adjusting for confounding variables among 1,312 participants.

• Advances in environmental research
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• 제11권1호
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• pp.31-38
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• 2022

The current observational epidemiological study analyzed blood lead levels (BLLs) in occupationally exposed workers from Riyadh region, Saudi Arabia and correlated them with the alterations in the differential cell populations of the WBC panel (lymphocytes [Lym %], mixed [Mid %] cells, and neutrophils [Neu %]). In addition, we examined the effect of confounding factors and their relation to BLLs. BLLs were estimated using the LeadCare II analyzer and hematological parameters using the ADVIA 120 analyser. An inferential analysis was conducted to detect association between the observations and the subjects' clinical characateristics. A total of 132 male subjects were included in the final analyses. Based on CDC guidelines, the subjects were categorized as Group I (BLL <10 ㎍/dL; n=118) or Group II (BLL >10 ㎍/dL; n=14) with average BLLs of 4.4 ㎍/dL and 18.1 ㎍/dL, respectively (p <0.0001). The percentages of Mid cells (p <0.0001) and neutrophils (p=0.048), were significantly altered in subjects with High BLL. A regression analysis indicated that subjects > 50 years of age had significantly higher BLLs (53.2 ㎍/dL) than younger age sub-groups (p <0.0001). Age, education, and profession were significant predictors for lead toxicity. Pb exposure is a major public health issue in Saudi Arabia and calls for further investigations on the cellular and molecular effects on hematological system.

• 응용통계연구
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• 제36권1호
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• pp.63-83
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• 2023

기존의 많은 연구에서 도시공원을 비롯한 녹지와 유아 행복감 간에 유의미한 상관관계를 도출했다. 또한 이를 통해 간접적으로 도시공원의 면적/근접성이 유아기의 행복감 증진에 효과가 있을 것이라 유추하였다. 하지만 관찰된 자료를 통한 인과효과 추정은 교란 변수의 적절한 조정을 필요로하고, 이런 관점에서 도시공원의 면적과 유아 행복감의 인과관계는 명확히 밝혀지지 않았다고 할 수 있다. 본 연구에서는 한국아동패널 자료를 이용하여 도시공원의 면적이 유아 행복감에 미치는 영향에 대한 인과효과를 추정하였다. 교란 변수를 조정하기 위한 방법으로 회귀 모형을 이용한 조정(regression adjustment), 가중치 기법(weighting), 그리고 매칭(matching) 등을 이용하였고, 각 방법들의 중요 개념을 분석 결과에 앞서 기술하였다. 교란 변수의 선택에 있어서 유향 비순환 그래프(directed acyclic graph)를 사용하였다. 분석 결과, 기존의 상관관계를 이용한 결론과는 다르게 도시공원의 면적과 유아 행복감 간에는 유의미한 인과효과가 존재하지 않았다.

• Journal of Yeungnam Medical Science
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• 제40권4호
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• pp.373-380
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• 2023

Background: The association between dental amalgam fillings and urine mercury concentrations was investigated in this study to assess the health risks associated with dental amalgams. Methods: This cross-sectional study included 99 women in their 20s who visited the dental clinic in Daegu, Korea. The 99 participants were composed of 68 subjects who had dental amalgam fillings (exposure group) and 31 subjects who did not have dental amalgam fillings (nonexposure group). Oral examinations were conducted by a single dental hygienist, sociodemographic features were investigated as confounding variables, and urine mercury concentrations were measured using an automatic mercury analyzer. Results: The mean±standard deviation of the urine mercury concentrations of the exposure and nonexposure groups were 1.50±1.78 ㎍/g creatinine and 0.53±0.63 ㎍/g creatinine, respectively. The exposure group showed significantly higher levels than the nonexposure group (p<0.01). The urine mercury concentration significantly increased with an increase in the number of teeth filled with amalgam, cavity surfaces involved, and number of defective amalgam fillings, and according to the latest exposure time (p<0.001). In the multiple regression analysis of amalgam-related factors and urine mercury concentrations after correction for confounding factors, the urine mercury concentration in the group with six or more amalgam-filled teeth, 11 or more cavity surfaces, and two or more defective amalgams was significantly higher than that in the nonexposure group (p<0.001). Conclusion: According to this study, exposure to dental amalgams was confirmed to significantly affect urine mercury concentrations.

• Clinical Nutrition Research
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• 제12권2호
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• pp.116-125
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• 2023

The present study sought to examine the association between an infant's anthropometric outcomes with maternal Dietary Inflammatory Index (DII) and Alternate Healthy Eating Index for Pregnancy (AHEI-P) scores during the third trimester of pregnancy. This prospective cohort study was applying 130 pregnant women, at the pregnancy training center in west Tehran, Iran (November 2020 to July 2021). The maternal dietary intake, and body mass index (BMI), and social economic level were evaluated. The data about birth weight, birth height, head circumference, and, gestational age at birth were extracted from each child's health records. The ultimate sample included 122 (93.8%) pairs of women/newborn children. The participants, mean age was 28.13 ± 4.66 years with gestational age between 28 to 40 weeks and the mean of BMI was 24.62 ± 3.51. Our outcomes, after adjustment for confounding factors, suggested that those newborn infants in the highest quartile of maternal DII score had a significantly lower weight (p < 0.001) and height (p = 0.05), in comparison to those in the lowest quartile, but not head circumference (p = 0.18). Moreover, after adjustment for confounding factors, results suggested that those newborn infants in the First quartile of maternal AHEI-P score had a significantly lower weight (p = 0.018) and, in comparison to those in the higher quartile. It appears that newborn infants with lower maternal DII and higher AHEI-P scores may have a better anthropometric outcome. Further longitudinal and in-depth qualitative and quantitative studies, with a longer-term follow-up, is warranted to support the integrity of our outcomes.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• 제25권2호
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• pp.132-142
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• 2023

Objective: Dual antiplatelet therapy (DAPT) is usually temporarily used after stent-assisted coil embolization (SACE), and is commonly converted to mono antiplatelet therapy (MAPT) for indefinitely. In this study, we aimed to find the possibility of discontinuing MAPT, and to determine the proper period of DAPT use. Methods: We used the Standard Sample Cohort DB dataset from the National Health Insurance Sharing Service. Among approximately 1 million people in the dataset, SACE was performed in 214 patients whose data this study analyzed. The relationship between discontinuation of antiplatelet therapy and intracranial hemorrhage or cerebral infarction was analyzed using multiple logistic regression, considering all confounding variables. The survival rate according to the continuation of antiplatelet therapy was obtained using Kaplan-Meier analysis, and the difference in survival rate according to the continuation of antiplatelet therapy was verified using the log-rank test. The hazard ratio according to continuation of antiplatelet therapy was obtained using the Cox proportional hazards model. The analysis was conducted by applying the same statistical method to the duration of DAPT use. Results: Among 214 patients who underwent SACE, 50, 159 and five patients continued, discontinued and did not use antiplatelet therapy (except at the time of procedure), respectively. In multiple logistic regression analysis, discontinuation of antiplatelet agents (including aspirin) and the period of DAPT use did not affect the occurrence of intracranial hemorrhage or cerebral infarction, considering various confounding factors. In the survival analysis according to the continuation of antiplatelet agents, patients who continued to use antiplatelet agents had a higher survival rate than those in other groups (p=0.00). The survival rate was higher in the rest of the group than in the group that received DAPT for three months (p=0.00). Conclusions: Continuation of antiplatelet agents or the period of DAPT use did not affect the occurrence of intracranial hemorrhage or cerebral infarction. Considering the survival rate, it would be better to maintain at least three months of antiplatelet therapy and it might be recommended to continue DAPT use for 12 months.

• Annals of Occupational and Environmental Medicine
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• 제34권
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• pp.25.1-25.11
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• 2022

Background: Many studies have been conducted on presenteeism and absenteeism, but the relationship between presenteeism and absenteeism is unclear. This study was undertaken to investigate the effect of presenteeism on future absenteeism. Methods: This study was conducted on non-white collar workers that underwent general health examinations in 2014 and 2015. We asked subjects to fill out a questionnaire about their experiences of presenteeism for the past one year in 2014. In 2015, it was checked whether the same subjects had any experience of absence from work due to injury or disease during the past year. The χ² test was used to analyze relationships between sociodemographic and occupational characteristics, presenteeism, and absence. Odds ratios (ORs) were calculated by logistic regression analysis controlled for confounding factors. Results: A total of 12,572 workers were included in the study. For workers who experienced presenteeism, the OR for injury absence was 2.705 (95% confidence interval [CI]: 2.044-3.581), and the OR for disease absence was 4.906 (95% CI: 3.996-6.024) after adjusting for sociodemographic and occupational confounding factors. For men that experienced presenteeism, the OR for injury absence was 3.035 (95% CI: 2.258-4.081), and the OR for disease absence was 5.508 (95% CI: 4.340-6.989). For women that experienced presenteeism, the OR for injury absence was 1.322 (95% CI: 0.577-3.028), which was not significant, and the OR for disease absence was 3.629 (95% CI: 2.405-5.475). Conclusions: This study suggests that presenteeism can influence future absenteeism. The effect of presenteeism may depend on cause of absence. Men who experienced presenteeism showed greater effects on injury and disease absence than women. For women, experience of presenteeism had a significant effect on disease absence but not on injury absence.

• Asia pacific journal of information systems
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• 제10권3호
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• pp.181-197
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• 2000

The purpose of this study is to confirm whether the fit between the task and the information characteristics makes any effects on the user satisfaction. The task is defined as two sub-constructs representing the degree of exception and analyzability. The information characteristics is divided into the degree of aggregation, scope and timeliness of information. User satisfaction was used as a surrogate measure of the performance of information systems. The computer self-efficacy was used to control any confounding effects. Field research method using questionnaires was employed to empirically investigate the relationship among the variables. Findings of the study are summarized as follows: the fit between the task and the aggregation of information and between the task and the scope of information turned out to have significant effects on information system performance. The implication of such results is that under highly exceptional or less analyzable task environment, less-aggregated or broad information is more appropriate.

• 품질경영학회지
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• 제38권1호
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• pp.42-51
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• 2010

For the fractional factorial designs, the resolution-IV designs can be used when we want to estimate the main effects and to investigate the structure of the non-negligible two-factor interaction effects, when the three-factor and higher order interaction effects are all negligible. However we need to add the additional treatment combinations in order to identify the influential interactions for the resolution-IV fractional factorial designs. In this paper we investigate the statistical structure for 3-level resolution-IV designs constructed by fold-over scheme and introduce a method for analyzing the influential two-factor interactions.

• 한국보건간호학회지
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• 제34권1호
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• pp.87-98
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• 2020

Objectives: The aim of this study was to identify the relation of sexual orientation and suicidal ideation. Methods: The study includes 33,309 Korean high school students: 31,213 of whom had no experience of sexual intercourse, 1,739 had heterosexual sexual intercourse, 191 had homosexual sex, and 166 had bisexual intercourse. The study used the 12th(2016) Korea Youth Risk Behavior Web-based Survey with complex sample logistic regression. Results: Adjusted confounding variables related to suicidal ideation of participants except for sexual orientation were analyzed, and suicidal ideation was higher in the homosexual and bisexual groups. These two groups showed a higher risk of suicidal ideation (homosexual: OR=2.28, 95% CI:1.54-3.39) (bisexual: OR=2.78, 95% CI:1.61-4.81). Conclusions: The study results showed sexual orientation was associated with suicidal ideation. Further studies and evaluations are needed.