• 대한예방의학회:학술대회논문집
• /
• 대한예방의학회 1994년도 교수 연수회(환경)
• /
• pp.417-425
• /
• 1994

Although animal studies have been used most often for quantitative risk assessment, it is generally recognized that well-conducted epidemiologic studies would provide the best basis for estimating human risk. However, there are several features related to the design and analysis of epidemiologic studies that frequently limit their usefulness for quantitating risks. The lack of accurate information on exposure in epidemiologic studies is perhaps the most frequently cited limitation of these studies for risk assessment. However. other features of epidemiologic study design, such as statistical power, length of follow-up, confounding, and effect modification, may also limit the inferences that can be drawn from these studies. Furthermore, even when the aforementioned limitations are overcome, substantial uncertainty exists concerning the choice of an appropriate statistical (or biologic) model for extrapolation beyond the range of exposures observed in a particular study. This paper focuses on presenting a review and discussion of the methodologic issues involved in using epidemiologic studies for risk assessment. This review concentrates on the use of retrospective, cohort, mortality studies of occupational groups for assessing cancer risk because this is the most common application of epidemiologic data for quantitative risk assessment (QRA). Epidemiologic data should not be viewed as a panacea for the problems inherent in using animal bioassay data for QRA. Rather, information that can be derived from epidemiologic and toxicologic studies complement one another, and both data sources need to be used to provide the best characterization of human risk.

• Radiation Oncology Journal
• /
• 제35권3호
• /
• pp.189-197
• /
• 2017

Locally advanced prostate cancer (LAPC) is defined as histologically proven T3-4 prostatic adenocarcinoma. In this review, we define the individual roles of radiotherapy (RT), short-term (ST-) and long-term (LT-) androgen deprivation therapy (ADT), and their combination in multimodal therapy for LAPC. Despite limitations in comparing the clinical outcomes among published papers, in the present study, a trend of 10-year clinical outcomes was roughly estimated by calculating the average rates weighted by the cohort number. With RT alone, the following rates were estimated: 87% biochemical failure, 34% local failure (LF), 48% distant metastasis (DM), 38% overall survival (OS), and 27% disease-specific mortality (DSM). Those associated with ADT alone were 74% BCF, 54% OS, and 25% DSM, which appeared to be better than those of RT alone. The addition of ADT to RT produced a notable local and systemic effect, regardless of ST- or LT-ADT. The LF rate decreased from 34% with RT alone to 21% with ST-ADT and further to 15% with LT-ADT. The DM and DSM rates also showed a similar trend among RT alone, RT+ST-ADT, and RT+LT-ADT. The combination of RT+LT-ADT resulted in the best long-term clinical outcomes, indicating that both RT and ADT are important parts of multimodal therapy.

• 대한의생명과학회지
• /
• 제22권4호
• /
• pp.189-198
• /
• 2016

The purpose of this study was to examine the effect of social support on type 2 diabetes by classifying it into diabetes and impaired fasting blood sugar, a pre-diabetic state. Subjects of this study were 22,846 adults aged 30 years or above who agreed and registered to participate in the "Korean Health Examine Cohort (KOEX)" study that simultaneously collects questionnaires and biological samples at 8 university hospitals around the nation. Normal fasting blood sugar was defined as below 100 mg/dL, and impaired fasting blood sugar was defined as 100~125 mg/dL. Diagnosis of diabetes was defined as fasting blood sugar of 126 mg/dL or above, diagnosis by a doctor, or medication of insulin or oral hypoglycemic agent. Social support groups were divided into 4 groups, and Group 1 (G1) had high positive support and low negative support. This is the reference group with the highest social support. During multivariate analysis, female group (G3) that had high positive support and high negative support showed prevalence of impaired fasting blood sugar 1.19 times higher (95% CI = 1.02~1.41) than G1. As this study confirmed that social support increases fasting blood sugar of women after correction for socioeconomic status, health behavior, and biological and medical variables, it implies the importance of social relations such as social support in addition to management of personal risk factors for prevention of type 2 diabetes.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권21호
• /
• pp.9165-9170
• /
• 2014

Purpose: This study evaluated the effect of an Educational Program on Palliative Care for MPM for Nurses in Japan. Program: The 5-h program consisted of lectures and care planning group work. Materials and Methods: This study used a pretest-posttest design with a single cohort of nurses and included a Difficulties in Palliative Care for Patients with MPM (DPCMPM) Scale with 15 items. The pre- and posttest scores were compared using a t-test. Results: We included 27 female nurses with a mean of 14.4 years of nursing experience. In 12 of 15 DPCMPM items, the posttest difficulty scores were lower than the pretest scores. Participants highly evaluated the program for validity, clarity, clinical usefulness, and the facilitators. The Palliative Care for MPM Handbook for Nurses was developed as an educational tool for clinical settings. Conclusions: The Educational Program on Palliative Care for MPM for Nurses was effective in reducing nursing difficulties.

• Safety and Health at Work
• /
• 제2권3호
• /
• pp.243-249
• /
• 2011

Objectives: Cement contains hexavalent chromium, which is a human carcinogen. However, its effect on cancer seems inconclusive in epidemiologic studies. The aim of this retrospective cohort study was to elucidate the association between dust exposure in the cement industry and cancer occurrence. Methods: The cohorts consisted of male workers in 6 Portland cement factories in Korea. Study subjects were classified into five groups by job: quarry, production, maintenance, laboratory, and office work. Cancer mortality and incidence in workers were observed from 1992 to 2007 and 1997-2005, respectively. Standardized mortality ratios and standardized incidence ratios were calculated according to the five job classifications. Results: There was an increased standardized incidence ratio for stomach cancer of 1.56 (27/17.36, 95% confidence interval: 1.02-2.26) in production workers. The standardized mortality ratio for lung cancer increased in production workers. However, was not statistically significant. Conclusion: Our result suggests a potential association between cement exposure and stomach cancer. Hexavalent chromium contained in cement might be a causative carcinogen.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권5호
• /
• pp.2323-2328
• /
• 2014

Background: Epidemiological findings are controversial relating to the relationship between dietary folate intake and the risk of breast cancer. We therefore conducted a meta-analysis of prospective cohort studies to clarify this association. Materials and Methods: PUBMED, EMBASE, and MEDLINE databases were searched for all relevant literature published in English from January 1, 1966 to August 2013. Summary relative risk (RR) and 95% confidence intervals (CIs) were calculated using a fixed or random effects model. Results: Dietary folate intake was not significantly associated with the risk of breast cancer. The combined RR with 95%CI for the highest vs. lowest category dietary intake of folate [fifteen studies; 1,836,566 participants and 24,083 patients with breast cancer] was 0.98 (0.90-1.05). Among subgroup analysis by menstrual status, hormonal status and the consumption of alcohol, methionine and vitamin B12, no significant association was observed for the dietary intake of folate and the risk of breast cancer. Dose-response analysis showed that a 220 ${\mu}g/day$ increment in dietary folate intake was not associated with the risk of breast cancer. Conclusions: Our findings indicate that dietary folate intake has no significant effect on the risk of breast cancer.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권13호
• /
• pp.5161-5166
• /
• 2014

Our aim was to access the association between recreational physical activity (RPA) and risk of ovarian cancer (OC). The studies were retrieved from the PubMed and Embase databases up to February 20th, 2014. Risk ratios (OR) and 95% confidence intervals (CI) were used to estimate effect sizes. Random-effects or fixed-effects models were used to pool the data. The trim and fill method was applied for sensitivity analysis. Begg's rank correlation test and Egger's regression asymmetry test were employed to assess the publication bias. A total of 6 studies (435398 participants including 2983 OC patients) were included in this meta-analysis. The overall estimate indicated that there was weakly inverse association between RPA and OC risk (RR=0.90, 95%CI: 0.72-1.12, p=0.335). Meanwhile, for prospective cohort studies, a result consistent with the overall estimate was obtained (RR=1.12, 95% CI: 0.88-1.42, p=0.356). However, for case control studies, the pooled estimate of RR was 0.76 (95%CI: 0.64-0.90, p=0.002), indicating a clear significant association between RPA and OC risk. In addition, the sensitivity analysis indicated a significant link between RPA and risk of OC after removing Lahmann's study (RR=0.80, 95% CI: 0.68-0.93, p=0.004). No significant publication bias was found (Begg's test: p=1.00; Egger's test: p=0.817). In conclusion, our meta-analysis indicated a weakly inverse relationship between RPA and the occurrence of OC.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권3호
• /
• pp.791-794
• /
• 2012

A retrospective cohort study was carried out with 340 female breast cancer at a teaching university in northeast of Thailand recruited and followed-up until the end of 2006. Survival probabilities were estimated using the Kaplan-Meier method. 161 cases were alive after five years and 58 patients were lost to follow-up. The overall observed survival rates at 1, 3 and 5 years were 83.3%, 59.9% and 42.9%, respectively. When analysis was conducted for stage combined into 2 groups, early (stage I, II and unknown) and late (stage III and IV), the 5-year survival rate for early stage (60%; 95%CI: 0.51-0.67), was higher than for late stage (27%; 95%CI: 0.19-0.34) with high statistical significance (p<0.001). The hazard ratio of patients with stage IV was 11.6 times greater than for stage I (p=0.03). The findings indicate that the different stages of breast cancer markedly effect the overall survival rate.

• 한국주거학회논문집
• /
• 제9권1호
• /
• pp.33-42
• /
• 1998

This study has been designed to analyze longterm trend of home-ownership probability over the family life cycle. In this study, 633 female household heads were interviewed on their critical life event such as pregnancy, birth or death of households, marriage, and residential movement between 1987 and 1990 in Oxaca, Mexico. The raw data composed of 100,000 lines were transformed into yearly segmented observation data, proposed by Allison. The results are drawn as follws: 1) There is significant effect of marriage cohort on residential mobility and home ownership: couples who married in 1960s are likely to change their residence at early stage of family life than those who married in 1940s. They also have lower probability of home ownership for 10 years after marriage than the other cohorts. 2) Over all the cohorts, it is consistent tendency that probability of home ownership continuously increases over the entire family life cycle for 40 years. 3) Of the logistic regression analysis of home ownership on household socioeconomic variables, the homeownership was positively related with age of marriage and time since marriage, and was negatively related with education of female head. Over in this study, it is proven that home owenership is ultimate goal of most families, and it is a function of family event variables.

• Osong Public Health and Research Perspectives
• /
• 제8권5호
• /
• pp.308-317
• /
• 2017

Objectives: We aimed to examine the effects of various leisure activities on cognitive impairment in young-old (aged 65-74 years) and old-old (aged ${\geq}75$ years) adults. Methods: In total, 10,279 elderly Korean individuals from the 2014 Korean National Survey on Older Adults' cohort were enrolled in our study. Cognitive impairment was assessed using the standardized score of the Mini-Mental State Examination for Dementia Screening, whereas leisure activities were recorded via self-reporting of the extent and type of leisure activity the subjects involved in over the past year. Multivariate logistic regression was used to assess the effect of leisure activities on cognitive impairment, while controlling for potential covariates. Results: The subjects were more likely to participate in cognitive activities than in non-exercise physical activities. After controlling for selected covariates, involvement in cognitive activities was found to be a significant predictor of cognitive impairment in both the groups, whereas involvement in non-exercise physical activities was not a predictor of cognitive impairment in individuals aged ${\geq}75$ years. Moreover, depressive symptoms, rural residence, and hearing difficulties were common predictors of cognitive impairment among elderly-Korean-individuals. Conclusion: Leisure activity involvement may help delay cognitive impairment, which is often concomitant with aging. Hence, an early intervention service may significantly benefit both young-old and old-old individuals.