• Title, Summary, Keyword: Retrospective studies

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Logistic Regression for Retrospective Studies

  • Shin, Mi-Young
    • Journal of the Korean Society for Quality Management
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    • v.22 no.4
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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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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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    • v.35 no.4
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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.

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

  • Kim, Seong-jae;Lee, Hae-kwang
    • Cartoon and Animation Studies
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    • pp.107-128
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    • 2017
  • Time is an indispensable element in creating a story. This makes comics artists use various time techniques such as prolepsis, summary, ellipsis and flashback to increase immersion in story when they create comics. This is intended to make a study on retrospective structure among various temporal structures. Retrospective structure means progress in different time sequence, and increases immersion by making readers become strained or relaxed. Besides, retrospective structure plays a role of increasing or decreasing the pace of story. The person who systematically put the retrospective structure into shape is $G\acute{e}rard$ Genette. He in his book "Narrative Discourse" classified retrospective structure into three types. These are made up of structure of analepse externes, analepse internes and analepse mixted. This makes a study on retrospective structure in narrative comics based on $G\acute{e}rard$ Genette's retrospective structure. To this end, Kang Full's webtoon was analyzed. The reason to analyze Kang Full's is that this work has storyline where things happening in parental generation is interwined with things in offspring generation, accordingly this is work suitable for studying the retrospective structure. This study is intended to examine whether three retrospective structures suggested by $G\acute{e}rard$ Genette are actually used through an analysis of , and as a result, it is intended to prove the fact that retrospective structure has an effect on immersion in work.

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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    • v.9 no.3
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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.

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

  • Park, Dong-Uk
    • Journal of Environmental Health Sciences
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    • v.37 no.1
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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.

A Systematic Review from the Journals of the Korean Oriental Medical Society. (대한한의학회지 및 대한한의학회 산하 정회원 학회의 학술진흥재단 등재지에 대한 천식 임상연구의 체계적 고찰)

  • Choi, Jun-Yong;Bang, Ji-Hyung;Shen, Feng-Yan;Jung, Hee-Jae;Jung, Sung-Ki
    • The Journal of Korean Medicine
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    • v.31 no.1
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    • pp.14-22
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    • 2010
  • Objectives: This study aimed to evaluate any clinical research regarding asthma published by the Korean Oriental Medical Society and its sub-societies for future rigorous clinical research. Methods: Every article relevant to asthma was initially obtained from journals in the Korean Oriental Medical Society and its sub-societies by electronic search at journal web sites or manual search. Journals were limited to those registered by the Korea Research Foundation. From initial findings, two independent reviewers selected clinical articles and these articles were further analyzed separately into predefined criteria according to prospective and retrospective studies. For prospective studies, quality assessment was also conducted. Results: From 99 articles initially obtained, 19 were finally analyzed. 14 were prospective whereas 5 were retrospective. Among the prospective articles, there were no randomized controlled trials and the non-randomized studies had no control groups, with several problems of quality regarding pre-calculated study size and unbiased assessment. None of the retrospective studies described asthma diagnosis objectively and outcome measures were either non-relevant to asthma or non-validated. Conclusions: Well-designed randomized controlled studies for asthma are needed and more rigorous non-randomized controlled studies should be conducted.

Effect of luteal phase support with vaginal progesterone on pregnancy outcomes in natural frozen embryo transfer cycles: A meta-analysis

  • Seol, Aeran;Shim, Yoo Jin;Kim, Sung Woo;Kim, Seul Ki;Lee, Jung Ryeol;Jee, Byung Chul;Suh, Chang Suk;Kim, Seok Hyun
    • Clinical and Experimental Reproductive Medicine
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    • v.47 no.2
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    • pp.147-152
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    • 2020
  • Objective: The purpose of this study was to determine the effect of vaginal progesterone for luteal phase support (LPS) on the clinical pregnancy rate (CPR) in natural frozen embryo transfer (FET) cycles via a meta-analysis. Methods: We performed a meta-analysis of randomized controlled trials (RCTs) and retrospective studies that met our selection criteria. Four online databases (PubMed, Embase, Medline, and the Cochrane Library) were searched between January 2017 and May 2017. Studies were selected according to predefined inclusion criteria and meta-analyzed using R software version 2.14.2. The main outcome measure was CPR. Results: A total of 18 studies were reviewed and assessed for eligibility. One RCT (n = 435) and three retrospective studies (n = 3,033) met the selection criteria. In a meta-analysis of the selected studies, we found no significant difference in the CPR (odds ratio [OR], 0.96; 95% confidence interval [CI], 0.60-1.55) between the vaginal progesterone and control groups. An analysis of the two retrospective cohort studies that reported the live birth rate (LBR) following FET showed a significantly higher LBR in the vaginal progesterone group (OR, 1.72; 95% CI, 1.21-2.46). A subgroup meta-analysis of FET conducted 5 days after injection of human chorionic gonadotropin showed no significant differences between the two groups with regard to the CPR (OR, 1.18; 95% CI, 0.90-1.55) or miscarriage rate (OR, 0.73; 95% CI, 0.36-1.47). Conclusion: The results of this meta-analysis of the currently available literature suggest that LPS with vaginal progesterone in natural FET cycles does not improve the CPR.

A Review on Diesel Engine Exhaust and Lung Cancer Risks (디젤엔진 배출물질과 폐암발생 위험에 관한 고찰)

  • Bae, Hyun-Joo;Park, Jeong-Im
    • Journal of Environmental Health Sciences
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    • v.38 no.4
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    • pp.277-290
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    • 2012
  • Objectives: Diesel engine exhaust (DE) accounts for a significant percentage of air pollutants that are associated with various health outcomes including mortality, asthma, chronic bronchitis, respiratory tract infection, etc. In June, 2012, the International Agency for Research on Cancer (IARC) released the assessment results that classified DE as "carcinogenic to humans" (Group 1). This review is therefore focused on the lung cancer risks of DE. Methods: Literatures were searched using PubMed with key words of "diesel exhaust", "lung cancer", and other related terms for the period between 1990 and 2012. A total of 295 articles were searched and sixteen epidemiologic studies were identified as potentially relevant. Results: Sixteen epidemiologic studies about the lung cancer risks of workers exposed to DE in various occupations were summarized in two tables, 1) retrospective cohort studies and 2) case-control studies. Increased lung cancer risk, although not always smoking adjusted, was observed in 6 out of 8 retrospective cohort studies and 4 of 8 case-control studies. Conclusions: Diesel fuel is widely used in Korea. Exposure to DE is confirmed to be a human carcinogen by IARC. Noncancer health risks of DE also need careful attention as DE is a major source of fine-particle pollution. Along with the efforts for reducing the DE emission through improvements of diesel engines and fuel, and the use of alternative fuels, comprehensive health risk assessment of DE should be conducted to minimize the adverse health effects.

A 10-YEAR RETROSPECTIVE CLINICAL STUDY OF $BR{\AA}NEMARK$ IMPLANTS ($Br{\aa}nemark$ 임플랜트의 10년 후향적 임상연구)

  • Bae, Jung-Yoon;Shin, Sang-Wan;Cho, Hyun-Jung;Kim, Young-Soo
    • The Journal of Korean Academy of Prosthodontics
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    • v.45 no.1
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    • pp.48-59
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    • 2007
  • Statement of problems: There are few studies which reported the survival rates of the specific dental implant systems in the Korean population with the follow-up periods longer than 5 years. Purpose: This retrospective clinical study was aimed to evaluate cumulative survival rate (CSR) of $Br{\aa}nemark$ implants followed for 10 years and to determine risk factors for implant failure. Material and methods: A total of 271 $Br{\aa}nemark$ implants in 83 patients were investigated with several identified risk factors. Life table analysis was undertaken to examine the CSR. Cox regression method was conducted to assess the association between potential risk factors and overall CSR. Results: Thirty implants failed. The 10-year implant CSR was 82.5%. Cox regression analysis demonstrated a significant predictive association between overall CSR and implant length (P<.05). Conclusion: An acceptable long-term result of $Br{\aa}nemark$ implant was achieved and implant length showed a significant association with the CSR.

Reduction of opioid intake after cooled radiofrequency denervation for sacroiliac joint pain: a retrospective evaluation up to 1 year

  • Tinnirello, Andrea
    • The Korean Journal of Pain
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    • v.33 no.2
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    • pp.183-191
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    • 2020
  • Background: Opioids can present intolerable adverse side-effects to patients who use these analgesics to mitigate chronic pain. In this retrospective analysis, cooled radiofrequency (CRF) denervation was evaluated to provide pain and disability relief and reduce opioid use in patients with sacroiliac joint (SIJ) derived low back pain (LBP). Methods: Twenty-seven patients with pain from SIJ refractory to conservative treatments, and taking opioids chronically (> 3 mo), were included. Numeric rating scale (NRS) and Oswestry disability index (ODI) scores were collected at 1, 6, and 12 months post-procedure. Opioid use between baseline and each follow-up visit was compared for the entire group and for those who experienced successful (pain reduction ≥ 50% of baseline value) or unsuccessful CRF denervation. Results: Severe initial mean pain (NRS score: 7.7 ± 1.0) and disability (ODI score: 50.1 ± 9.0), and median opioid use (morphine equivalent daily dose: 40 ± 37 mg) were significantly reduced up to 12 months post-intervention. CRF denervation was successful in 44.4% of the patients at 12 months. Regardless of procedure success, patients demonstrated similar opioid reductions and changes in opioid use at 12 months. Two patients (7.4%) experienced neuritis following CRF denervation. Conclusions: CRF denervation of the SIJ can safely elicit pain and disability relief, and reduce opioid use, regardless of intervention success. Future studies may support CRF denervation as a dependable therapy to alleviate opioid use in patients with SIJ-derived LBP and show that opioid use measurements can be a surrogate indicator of pain.