• 제목/요약/키워드: retrospective studies

검색결과 848건 처리시간 0.025초

반도체 웨이퍼 가공 근로자의 생식독성과 암 위험 역학연구에서 과거 노출평가 방법 고찰 (Critical review of retrospective exposure assessment methods used to associate the reproductive and cancer risks of wafer fabrication workers)

  • 박동욱;이경무
    • 한국산업보건학회지
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    • 제22권1호
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    • pp.9-19
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    • 2012
  • Objectives: The aim of this study is to critically review the exposure surrogates and estimates used to associate health effects in wafer fabrication workers such as spontaneous abortion and cancer, as well as to identify the limitations of retrospective exposure assessment methods Methods: Epidemiologic and exposure-assessment studies of wafer fabrication operations in the semiconductor industry were collected. Retrospective exposure-assessment methods used in cancer risk and mortality and reproductive toxicity were reviewed. Results: Eight epidemiologic papers and two reports compared cancer risk among workers in wafer fabrication facilities in the semiconductor industry with the risk of the general population. Exposure surrogates used in those cancer studies were fabrication(vs. non-fabrication), employment duration, manufacturing eras, job title (operator vs. maintenance worker) and qualitative classifications of agents without assessing specific agent or job-specific exposure. In contrast, specific operation, job title and agents were used to classify the exposure of fabrication workers, contributing to finding a significant association with spontaneous abortion (SAB). Conclusion: Further epidemiologic studies of fabrication workers using more refined exposure assessment methods are warranted in order to examine the associations between fabrication work, environment, and specific agents with cancer risk or mortality as used in SAB epidemiologic studies.

절제 불가능한 4기 대장암에서 고식적 수술의 임상적 효과 (Clinical Impact of Palliative Surgery in Unresectable Stage IV Colorectal Cancer)

  • 이윤석
    • Journal of Digestive Cancer Research
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    • 제5권1호
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    • pp.32-36
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    • 2017
  • In unresectable stage IV colorectal cancer, the role of palliative surgery is not defined clearly. The palliative surgery can be categorized into two surgeries; first, palliative primary tumor resection; second, palliative metastatectomy. Several retrospective studies reported initial palliative systemic chemotherapy in unresectable stage IV colorectal cancer did not increase primary tumor related complications such as obstruction, perforation and hemorrhage, so they insisted that primary tumor resection in asymptomatic stage IV colorectal cancer should be preserved. However, in terms of overall survival and cancer-specific or progression-free survival, several retrospective studies, especially using population-based big data, reported favored survivals in palliative primary tumor resection group. And also several studies reported that palliative metastatectomy such as liver resection without resection of lung metastasis showed better overall survivals. But those results from those studies came from retrospective studies and are likely to be affected by selection bias. Prospective randomized studies are needed to define the benefit of palliative primary tumor resection and metastatectomy in unresectable stage IV colorectal cancer. However, based on the updated evidences, the dogma that palliative primary tumor resection should be preserved in asymptomatic unresectable stage IV colorectal cancer should be questioned.

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Future Directions of Pharmacovigilance Studies Using Electronic Medical Recording and Human Genetic Databases

  • Choi, Young Hee;Han, Chang Yeob;Kim, Kwi Suk;Kim, Sang Geon
    • Toxicological Research
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    • 제35권4호
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    • pp.319-330
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    • 2019
  • Adverse drug reactions (ADRs) constitute key factors in determining successful medication therapy in clinical situations. Integrative analysis of electronic medical record (EMR) data and use of proper analytical tools are requisite to conduct retrospective surveillance of clinical decisions on medications. Thus, we suggest that electronic medical recording and human genetic databases are considered together in future directions of pharmacovigilance. We analyzed EMR-based ADR studies indexed on PubMed during the period from 2005 to 2017 and retrospectively acquired 1161 (29.6%) articles describing drug-induced adverse reactions (e.g., liver, kidney, nervous system, immune system, and inflammatory responses). Of them, only 102 (8.79%) articles contained useful information to detect or predict ADRs in the context of clinical medication alerts. Since insufficiency of EMR datasets and their improper analyses may provide false warnings on clinical decision, efforts should be made to overcome possible problems on data-mining, analysis, statistics, and standardization. Thus, we address the characteristics and limitations on retrospective EMR database studies in hospital settings. Since gene expression and genetic variations among individuals impact ADRs, pharmacokinetics, and pharmacodynamics, appropriate paths for pharmacovigilance may be optimized using suitable databases available in public domain (e.g., genome-wide association studies (GWAS), non-coding RNAs, microRNAs, proteomics, and genetic variations), novel targets, and biomarkers. These efforts with new validated biomarker analyses would be of help to repurpose clinical and translational research infrastructure and ultimately future personalized therapy considering ADRs.

서사만화에서의 회상구조 연구 -웹툰 <무빙>을 중심으로- (A study on retrospective structure in narrative comics -Focusing on webtoon -)

  • 김성재;이해광
    • 만화애니메이션 연구
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    • 통권46호
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    • pp.107-128
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    • 2017
  • 시간은 이야기를 만드는데 있어 꼭 필요한 요소이다. 이 때문에 작가들은 만화를 창작할 때 이야기의 몰입 감을 높이기 위해 예상, 요약, 생략, 플래시 백 같은 다양한 시간의 기법들을 사용한다. 본 연구에서는 여러 가지의 시간 구조 중 회상구조를 연구하고자 한다. 회상 구조는 시간의 순서를 바꿔서 진행하는 것으로 독자들을 긴장 시키거나 이완 시켜 몰입 감을 상승 시킨다. 또한 회상 구조는 이야기의 속도를 높이거나 느리게 하는 역할을 한다. 이런 회상 구조를 체계적으로 정리한 사람은 제라르 주네트이다. 그는 그의 저서 "서사담론"에서 회상 구조를 세 가지로 분류하였는데 외적 회상(analepse externes)과 내적 회상(analepse internes), 혼합적 회상(analepse mixted) 구조가 그것이다. 본 연구는 제라르 주네트의 회상 구조를 바탕으로 서사만화에서의 회상 구조를 연구한다. 이를 위해 강풀의 웹툰 <무빙>을 분석하였다. 강풀의 <무빙>을 분석한 이유는 이 작품은 부모 세대에서 벌어진 일이 자식 세대의 일과 얽히고설킨 이야기 구조를 가지고 있어 회상 구조를 연구하는데 적합한 작품이기 때문이다. 본 연구에서는 <무빙>의 분석을 통해 제라르 주네트가 제시한 세 가지 회상 구조가 실제로 작품에 쓰였는지를 알아보고, 이를 통해 회상 구조가 작품의 몰입 감에 영향을 미친다는 사실을 증명하는 것을 목적으로 한다.

Logistic Regression for Retrospective Studies

  • Shin, Mi-Young
    • 품질경영학회지
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    • 제22권4호
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    • pp.111-119
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    • 1994
  • We consider logistic models based on retrospective, case-control data with stratified samples and study the Weighted Exogeneous Sampling Maximum Likelihood (WESMU) We develop a consistent estimator of the asymptotic covariance matrix of the WESML estimator.

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Review for Retrospective Exposure Assessment Methods Used in Epidemiologic Cancer Risk Studies of Semiconductor Workers: Limitations and Recommendations

  • Park, Donguk
    • Safety and Health at Work
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    • 제9권3호
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    • pp.249-256
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    • 2018
  • This article aims to provide a systematic review of the exposure assessment methods used to assign wafer fabrication (fab) workers in epidemiologic cohort studies of mortality from all causes and various cancers. Epidemiologic and exposure-assessment studies of silicon wafer fab operations in the semiconductor industry were collected through an extensive literature review of articles reported until 2017. The studies found various outcomes possibly linked to fab operations, but a clear association with the chemicals in the process was not found, possibly because of exposure assessment methodology. No study used a tiered assessment approach to identify similar exposure groups that incorporated manufacturing era, facility, fab environment, operation, job and level of exposure to individual hazardous agents. Further epidemiologic studies of fab workers are warranted with more refined exposure assessment methods incorporating both operation and job title and hazardous agents to examine the associations with cancer risk or mortality.

청상보하탕에 대한 국내 임상연구 동향 분석 (A Literature Review of Domestic Clinical Studies on Chungsangboha-tang (Qingshangbuxia-tang))

  • 박지원
    • 대한한의학방제학회지
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    • 제32권3호
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    • pp.325-343
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    • 2024
  • Objective : To understand how Chungsangboha-tang (CSBHT) is being utilized in clinical practice and research in Korea, clinical studies related to CSBHT published in domestic academic journals were analyzed. Methods : The search was conducted using the following six databases: Korean Traditional Knowledge Portal, Oriental Medicine Advanced Searching Integrated System, ScienceON, Research Information Sharing Service, Koreanstudies Information Service System, and The Journal of Internal Korean Medicine. After selecting relevant literature published before June 24, 2024, the studies were classified and analyzed according to their research design. Results : The final selection comprised 20 studies categorized as follows: 1 non-randomized controlled trial and 10 before-and-after studies in prospective clinical research, along with 7 case reports and 2 retrospective chart reviews in retrospective clinical studies. Among the 233 participants included in these studies, 169 had asthma, 53 had chronic cough, and 5 had chronic obstructive pulmonary disease. Additionally, other conditions reported included Churg-Strauss syndrome, pulmonary Langerhans cell histiocytosis, non-tuberculous mycobacterial pulmonary disease, bronchiectasis, and pulmonary hypertension. CSBHT was administered as a decoction in 13 studies, as granules in 6 studies, and both in one study. The most frequently used assessment tools were pulmonary function tests and quality of life evaluations. For safety assessment, liver function test results and adverse events were reported. Conclusion : To enhance the utilization of CSBHT in Korean medicine clinical practice, continuous accumulation of domestic clinical research is essential. Moreover, meticulously designed randomized controlled trials are necessary to elevate the level of evidence.

Reliability and Validity of a Life Course Passive Smoke Exposure Questionnaire in an Australian Cohort From Childhood to Adulthood

  • Ezegbe, Chigozie;Magnussen, Costan G.;Neil, Amanda Louise;Buscot, Marie-Jeanne;Dwyer, Terence;Venn, Alison;Gall, Seana
    • Journal of Preventive Medicine and Public Health
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    • 제54권2호
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    • pp.153-159
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    • 2021
  • Objectives: Life course exposure to passive smoke may predict health, but there are few validated measures. We tested the reliability and validity of a retrospective life course passive smoking questionnaire. Methods: Participants from the third follow-up of the Childhood Determinants of Adult Health study (2014-2019, ages 36-49 years) retrospectively reported mother/father/other household member smoking when living at home during childhood, including duration (years) and smoking location (never/sometimes/always inside house). The severity of exposure index (SEI; sum of mother/father/other years smoked multiplied by smoking location), cumulative years of exposure (CYE; sum of mother/father/other years), and total household smokers (THS) were derived. The reliability of retrospective passive smoking reports was examined with intraclass correlation coefficients (ICCs) using household smoking reported 34 years earlier in 1985 by participants when aged 7-15 years. Construct validity was examined by correlating retrospective passive smoking with participants' smoking in adulthood and lung function in childhood and adulthood. Results: Among 2082 participants (mean±standard deviation [SD], 45.0±2.5 years; 55.2% females), THS ranged from 0 to 5 (mean±SD, 0.9±1.0), CYE ranged from 0 to 106 (mean±SD, 10.5±13.9), and SEI ranged from 0 to 318 (mean±SD, 24.4±36.0). Retrospective measures showed moderate agreement with total household smokers reported in childhood (ICC, 0.58 to 0.62). The retrospective measures were weakly but significantly (p<0.05) correlated with participants' smoking (r=0.13 to 0.15) and lung function (r= -0.05 to -0.06). Conclusions: The retrospective passive smoking questionnaire showed reasonable reliability and validity. This measure may be useful for epidemiological studies.

반도체 웨이퍼 가공 공정 역학 조사에서 과거 노출 평가 방법 고찰 (Retrospective Exposure Assessment of Wafer Fabrication Workers in the Semiconductor Industry)

  • 박동욱
    • 한국환경보건학회지
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    • 제37권1호
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    • pp.12-21
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    • 2011
  • The objective of this study is to review retrospective exposure assessment methods used in wafer fabrication operations to determine whether adverse health effects including mortality or cancer incidence are related to employment in particular work activities and to recommend an appropriate approach for retrospective exposure assessment methods for epidemiological study. The goal of retrospective exposure assessment for such studies is to assign each study subject to a workgroup in such a way that differences in exposure within the workgroups are minimized, as well as to maximize the contrasts in exposure between workgroups. To reduce the misclassification of exposure and to determine if adverse health effects including mortality or cancer incidence are related to particular work activities of wafer fabrication workers, a minimum requirement of work history information on the wafer manufacturing eras, job and department at which they were exposed should be assessed. Retrospective assessment of the task that semiconductor workers performed should be conducted to determine not only the effect of a particular job on the development of adverse health effects including mortality or cancer incidence, but also to adjust for the healthy worker effect. In order to identify specific hazardous agents that may cause adverse health effects, past exposure to a specific agent or agent matrices should also be assessed.

Derivation of a new dose constraint applicable to radioactive discharges from Korean nuclear power plants through retrospective dose assessment

  • Kim, Soyun;Cheong, Jae Hak
    • Nuclear Engineering and Technology
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    • 제54권10호
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    • pp.3660-3671
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    • 2022
  • A new methodology to derive a dose constraint for radioactive effluent from a unit of nuclear power plant (NPP) through retrospective assessment was developed to reflect operational flexibility in line with international standards. The new dose constraint can retain the safety margin between the offsite dose and the past dose constraints. As case studies, the new approach was applied to 24 Korean NPPs to address the limitations of the existing seven dose constraints that do not fully comply with current international radiation protection standards. Therefore, an effective dose constraint for Korean NPPs was proposed as no less than 0.15 mSv/y, which is comparable to the international practices and previous studies (0.05-0.3 mSv/y). Although the lower bound of the equivalent dose constraint was calculated as 0.17 mSv/y, it is not proposed in this study since the compliance with the derived effective dose constraint can prevent accompanied equivalent doses to any organs from exceeding equivalent dose limits. The new framework and the case studies are expected to contribute toward and support the revision of existing dose constraints for radioactive effluent from NPPs, ensuring better compliance with the current international safety standards as well as reflect the operational flexibility in practice.