• 제목/요약/키워드: Cohort analysis

검색결과 872건 처리시간 0.028초

The Prognostic Value of Lymph Node Ratio after Neoadjuvant Chemotherapy in Patients with Locally Advanced Gastric Adenocarcinoma

  • Zhu, Kankai;Jin, Hailong;Li, Zhijian;Gao, Yuan;Zhang, Qing;Liu, Xiaosun;Yu, Jiren
    • Journal of Gastric Cancer
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    • 제21권1호
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    • pp.49-62
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    • 2021
  • Purpose: This study aimed to investigate the prognostic value of lymph node ratio (LNR) in patients with locally advanced gastric cancer who received neoadjuvant chemotherapy. Materials and Methods: We retrospectively enrolled gastric cancer patients treated with neoadjuvant chemotherapy and curative surgery at the First Affiliated Hospital of Zhejiang University from 2004 to 2015 as the study cohort. Patients with the same inclusion criteria treated in 2016-2017 were enrolled as the validation cohort. Kaplan-Meier curves were assessed using the log-rank test to analyze the differences in overall survival (OS). Multivariate survival analysis was performed using the Cox proportional hazards model. The areas under the receiver operating characteristic curve of ypN and LNR categories for predicting the actual 3-year OS were compared. Results: A total of 265 patients were included in the proposal cohort. The median number of retrieved lymph nodes (rLNs) was 32. The number of positive lymph nodes (pLNs) increased as rLN increased (P=0.037), but the LNR remained relatively constant (P=0.462). The LNR was categorized into 4 groups according to the prognosis: ypNr0, node-negative with rLN>25; ypNr1, node-negative with rLN≤25 or 00.3. In the validation cohort of 43 enrolled patients, there was a clear distinction in OS that significantly (P<0.001) varied depending on the LNR values and LNR was the only independent prognostic factor in multivariate analysis (P<0.001). Conclusions: LNR was an independent prognostic factor for survival of patients with gastric cancer after preoperative chemotherapy and might be an alternative predictor for ypN stage.

소비의 불확실성에 따른 예비적 저축 동기 추정 (Estimating a Precautionary Saving Motive under Consumption Uncertainty)

  • 황진태;김성민
    • 경제분석
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    • 제26권3호
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    • pp.48-70
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    • 2020
  • 본 연구는 1994~2016년 '가계동향조사'의 미시자료 변수를 표본평균으로 전환하는 방식의 코호트 접근법을 사용하여 소비 불확실성이 존재하는 상황에서 예비적 저축 동기를 추정하였다. 이를 위해 오일러 방정식을 이용하여 도출된 상대적 신중도와 유동성 제약 관련 최초 소득을 통제한 회귀모형을 추정함으로써 예비적 저축 동기 여부를 살펴보았다. 추정 결과, 2SLS 집단 간 추정량(BE2SLS)의 경우 선행연구의 결과와 유사하게 상대적 신중도가 작게 추정되어 예비적 저축 동기가 존재한다고 보기 어려웠다. 반면, 2SLS 확률효과 추정량(RE2SLS)을 사용한 경우에는 예비적 저축 동기가 존재하는 것으로 나타났다. 또한, 유동성 제약 여부를 기준으로 나눈 그룹별 추정에서 유동성 제약 그룹이 미래의 불확실성에 더 민감하게 반응하는 것으로 나타났다.

Post-diagnosis Soy Food Intake and Breast Cancer Survival: A Meta-analysis of Cohort Studies

  • Chi, Feng;Wu, Rong;Zeng, Yue-Can;Xing, Rui;Liu, Yang;Xu, Zhao-Guo
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권4호
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    • pp.2407-2412
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    • 2013
  • Background and Objectives: Data on associations between soy food intake after cancer diagnosis with breast cancer survival are conflicting, so we conducted this meta-analysis for more accurate evaluation. Methods: Comprehensive searches were conducted to find cohort studies of the relationship between soy food intake after cancer diagnosis and breast cancer survival. Data were analyzed with comprehensive meta-analysis software. Results: Five cohort studies (11,206 patients) were included. Pooling all comparisons, soy food intake after diagnosis was associated with reduced mortality (HR 0.85, 95%CI 0.77 0.93) and recurrence (HR 0.79, 95%CI 0.72 0.87). Pooling the comparisons of highest vs. lowest dose, soy food intake after diagnosis was again associated with reduced mortality (HR 0.84, 95%CI 0.71 0.99) and recurrence (HR 0.74, 95%CI 0.64 0.85). Subgroup analysis of ER status showed that soy food intake was associated with reduced mortality in both ER negative (highest vs. lowest: HR 0.75, 95%CI 0.64 0.88) and ER positive patients (highest vs. lowest: HR 0.72, 95%CI 0.61 0.84), and both premenopausal (highest vs. lowest: HR 0.78, 95%CI 0.69 0.88) and postmenopausal patients (highest vs. lowest: HR 0.81, 95%CI 0.73 0.91). In additioin, soy food intake was associated with reduced recurrence in ER negative (highest vs. lowest: HR 0.64, 95%CI 0.44 0.94) and ER+/PR+ (highest vs. lowest: HR 0.65, 95%CI 0.49 0.86), and postmenopausal patients (highest vs. lowest: HR 0.67, 95%CI 0.56 0.80). Conclusion: Our meta-analysis showed that soy food intake might be associated with better survival, especially for ER negative, ER+/PR+, and postmenopausal patients.

Serum vitamin D status and metabolic syndrome: a systematic review and dose-response meta-analysis

  • Lee, Kyueun;Kim, Jihye
    • Nutrition Research and Practice
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    • 제15권3호
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    • pp.329-345
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    • 2021
  • BACKGROUD/OBJECTIVES: Evidence has suggested an association between serum vitamin D and metabolic syndrome (MetS), but prospective studies are very limited. The objective was to assess the dose-response association between serum vitamin D concentration and MetS risk using a systematic review and meta-analysis of updated observational studies. MATERIALS/METHODS: Using MEDLINE, PubMed, and Embase, a systematic literature search was conducted through February 2020 and the references of relevant articles were reviewed. A random-effects model was used to estimate the summary odds ratio/relative risk and 95% confidence interval (CI). Heterogeneity among studies was evaluated with I2 statistic. In total, 23 observational studies (19 cross-sectional studies, and four cohort studies) were included in the meta-analysis. RESULTS: The pooled estimates (95% CI) for MetS per 25-nmol/L increment in serum vitamin D concentration were 0.80 (95% CI, 0.76-0.84; I2 = 53.5) in cross-sectional studies, and 0.85 (95% CI, 0.72-0.98; I2 = 85.8) in cohort studies. Similar results were observed, irrespectively of age of study population, study location, MetS criteria, and adjustment factors. There was no publication bias for the dose-response meta-analysis of serum vitamin D concentrations and MetS. CONCLUSIONS: Dose-response meta-analysis demonstrated that a 25-nmol/L increment in the serum vitamin D concentration was associated with 20% and 15% lower risks of MetS in cross-sectional studies and cohort studies, respectively.

인구 고령화와 임금구조: 1990년대 이후 한국 남성 근로자의 세대규모효과에 대한 실증분석 (Population Aging and Wage Structure: An Empirical Study of Cohort Size Effect on Korean Male Worker since 1990)

  • 엄동욱
    • 한국인구학
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    • 제31권1호
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    • pp.75-97
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    • 2008
  • 최근 우리나라는 고령화가 급속도로 진전되면서 향후 생산가능인구의 감소와 더불어 인구구조, 특히 연령구조(age structure) 또한 급격한 변화를 겪을 것으로 예상되고 있다. 이에 본 연구는 이러한 인구구조의 변화가 임금구조에 미치는 영향을 파악하기 위해 연령별 세대규모(cohort size)에 초점을 맞추어 세대규모효과로 인해 연령-임금 프로파일이 어떻게 변모하였는지를 분석하였다. 실증분석은 Wright(1991)의 모형을 기초로 노동부의 '임금구조기본통계조사' 원자료($1990년{\sim}2006$년)의 남성 근로자 데이터를 활용한 Weighted OLS 회귀분석으로 이루어졌다. 추정결과에서는 고졸 근로자 및 대졸이상 고학력 근로자에게서 세대규모효과가 발견되었는데, 고졸 근로자의 경우 기존 Welch(1979)나 Wright(1991)의 연구와 유사한 결과가 나타났지만, 대졸이상 근로자의 경우 반대로 정(+)의 신규진입효과와 부(-)의 지속효과가 나타났다. 따라서 고졸 근로자는 임금수준에서 세대규모로 인한 불이익을 받는 반면, 고학력 취업자의 경우 최근 청년실업 및 취업난의 상황에도 불구하고 상대적으로 작은 세대규모로 인해 임금수준에서 이득을 보고 있다는 것을 보여주고 있다. 이는 기존의 연구가 주로 노동수요 측면에 치우쳐 있다는 점에서 노동공급측면에서 인구 고령화에 따른 인구구조의 변화에 관심을 둔 연구가 필요하다는 것을 시사한다.

직업적 트리클로로에틸렌 노출과 비호지킨림프종의 연관성 (Occupational Exposure to Trichloroethylene and Non-hodgkin Lymphoma Risk)

  • 전재범;한소희;윤형석;이은정;이경무
    • 한국환경보건학회지
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    • 제37권5호
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    • pp.358-368
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    • 2011
  • Objectives: In order to evaluate the association between occupational exposure to chloroethylene (TCE) and risk of non-Hodgkin lymphoma (NHL), we conducted a meta-analysis of retrospective cohort studies and casecontrol studies and attempted to summarize the evidence of the association from molecular-epidemiological studies and experiments with human cells. Methods: In the meta-analysis, we restricted the analysis to those studies with data for chlorinated solvents, degreasers, or TCE. Studies involving dry cleaners or launderers were excluded from the analysis because use of TCE as a dry cleaning fluid has been rare since the 1960s. The data were combined using a random-effects model to estimate the summary risks (OR and RR) and 95% confidence intervals (CIs). Molecular evidence of the effect of TCE on human immune system were also reviewed and summarized. Results: Occupational exposure to TCE was strongly associated with NHL among cohort studies (number of studies=13, summary RR=1.33, 95% CI=1.04-1.70) whereas the association was not statistically significant among case-control studies (number of studies=15, summary OR=1.10, 0.98-1.23). When exposure level was considered, it became statistically significant for the highest exposure level (number of studies=5, summary OR=1.70, 1.25-2.32). Molecular evidences showed that TCE exposure in human or cultured human cells may cause a significant decrease immune cell subsets and changes in hormone levels related to immune response. Conclusions: Our results from meta-analysis and additional molecular evidence suggest that occupational exposure to TCE may cause NHL. However, unmeasured potential confounding and unclear dose-response relationships warrant further study on the role of TCE exposure in NHL carcinogenesis.

Alcohol Consumption and Breast Cancer Survival: A Metaanalysis of Cohort Studies

  • Gou, Yun-Jiu;Xie, Ding-Xiong;Yang, Ke-Hu;Liu, Ya-Li;Zhang, Jian-Hua;Li, Bin;He, Xiao-Dong
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권8호
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    • pp.4785-4790
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    • 2013
  • Background and Objectives: Evidence for associations between alcohol consumption with breast cancer survival are conflicting, so we conducted the present meta-analysis. Methods: Comprehensive searches were conducted to find cohort studies that evaluated the relationship between alcohol consumption with breast cancer survival. Data were analyzed with meta-analysis software. Results: We included 25 cohort studies. The meta-analysis results showed that alcohol consumption was not associated with increased breast cancer mortality and recurrence after pooling all data from highest versus lowest comparisons. Subgroup analyses showed that pre-diagnostic or post-diagnostic consumpotion, and ER status did not affect the relationship with breast cancer mortality and recurrence. Although the relationships of different alcohol consumption with breast cancer mortality and recurrence were not significant, there seemed to be a dose-response relationship of alcohol consumption with breast cancer mortality and recurrence. Only alcohol consumption of >20 g/d was associated with increased breast cancer mortality, but not with increased breast cancer recurrence. Conclusion: Although our meta-analysis showed alcohol drinking was not associated with increased breast cancer mortality and recurrence, there seemed to be a dose-response relationship of alcohol consumption with breast cancer mortality and recurrence and alcohol consumption of >20 g/d was associated with increased breast cancer mortality.

The Clinical Impact of Advanced Age on the Postoperative Outcomes of Patients Undergoing Gastrectomy for Gastric Cancer: Analysis Across US Hospitals Between 2011-2017

  • Lee, David Uihwan;Fan, Gregory Hongyuan;Chang, Kevin;Lee, Ki Jung;Han, John;Jung, Daniel;Kwon, Jean;Karagozian, Raffi
    • Journal of Gastric Cancer
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    • 제22권3호
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    • pp.197-209
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    • 2022
  • Purpose: This study systematically evaluated the implications of advanced age on post-surgical outcomes following gastrectomy for gastric cancer using a national database. Materials and Methods: The 2011-2017 National Inpatient Sample was used to isolate patients who underwent gastrectomy for gastric cancer. From this, the population was stratified into those belonging to the younger age cohort (18-59 years), sexagenarians, septuagenarians, and octogenarians. The younger cohort and each advanced age category were compared in terms of the following endpoints: mortality following surgery, length of hospital stay, charges, and surgical complications. Results: This study included a total of 5,213 patients: 1,366 sexagenarians, 1,490 septuagenarians, 743 octogenarians, and 1,614 under 60 years of age. Between the younger cohort and sexagenarians, there was no difference in mortality (2.27 vs. 1.67%; P=0.30; odds ratio [OR], 1.36; 95% confidence interval [CI], 0.81-2.30), length of stay (11.0 vs. 11.1 days; P=0.86), or charges ($123,557 vs. $124,425; P=0.79). Compared to the younger cohort, septuagenarians had higher rates of in-hospital mortality (4.30% vs. 1.67%; P<0.01; OR, 2.64; 95% CI, 1.67-4.16), length of stay (12.1 vs. 11.1 days; P<0.01), and charges ($139,200 vs. $124,425; P<0.01). In the multivariate analysis, septuagenarians had higher mortality (P=0.01; adjusted odds ratio [aOR], 2.01; 95% CI, 1.18-3.43). Similarly, compared to the younger cohort, octogenarians had a higher rate of mortality (7.67% vs. 1.67%; P<0.001; OR, 4.88; 95% CI, 3.06-7.79), length of stay (12.3 vs. 11.1 days; P<0.01), and charges ($131,330 vs. $124,425; P<0.01). In the multivariate analysis, octogenarians had higher mortality (P<0.001; aOR, 4.03; 95% CI, 2.28-7.11). Conclusions: Advanced age (>70 years) is an independent risk factor for postoperative death in patients with gastric cancer undergoing gastrectomy.

대학 졸업생의 직업선택과 임금 수준 (An Analysis of Job Selection, Major-Job Match and Wage Level of College Graduates)

  • 박재민
    • 기술혁신학회지
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    • 제14권1호
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    • pp.22-39
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    • 2011
  • 본 논문은 대학 졸업생의 숙련 불일치 문제에 대한 분석의 일환으로 임금으로 대표되는 노동시장성과에 대해 전공-직업 일치의 시각에서 접근한 것이다. 실증 분석에 있어서는 선행연구들에서 자주 제기되었던 표본선택편의 문제를 명시적으로 분석 과정에 반영하였고, 분석의 편의상 이항변수로 취급되었던 전공직업일치 변수도 설문조사가 제공한 다항선택변수로 설정하여 분석하였다. 특히 1982년, 1992년, 2002년 세 코호트에 대한 조사 결과를 활용하여 비교적 장기간에 걸친 노동시장의 구조적 변화도 고려하고자 하였다. 실증분석 결과, 전공일치 직업선택에 따른 표본선택편의와 전공직업일치의 임금효과를 확인할 수 있었다. 또 전공직업일치 정도와 비례해 임금프리미엄도 체증하고, 특히 전공계열별 분석을 통해 사회 계열, 공학 계열, 자연 계열에서 전공과 직업이 일치한 경우 상대적으로 높은 임금을 확인할 수 있었다. 그러나 전공 계열별로 선택편의의 영향에 차이가 있음도 볼 수 있었다. 또 1982년, 1992년, 2002년을 비교하면 1992년에 전공직업일치 경향은 급격히 낮아졌고 1992년과 2002년의 차이는 오히려 크지 않아 이 같은 숙련 불일치 현상이 상당히 오래 전부터 진행되어 온 현상임을 확인할 수 있었다.

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