• 제목/요약/키워드: Cox regression model

검색결과 208건 처리시간 0.02초

The Risk of Colorectal Cancer After Cholecystectomy or Appendectomy: A Population-based Cohort Study in Korea

  • Lee, Joonki;Choe, Sunho;Park, Ji Won;Jeong, Seung-Yong;Shin, Aesun
    • Journal of Preventive Medicine and Public Health
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    • 제51권6호
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    • pp.281-288
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    • 2018
  • Objectives: We investigated the association between cholecystectomy or appendectomy and the subsequent risk of colorectal cancer (CRC) in the Korean population. Methods: A retrospective cohort study was conducted with the National Health Insurance Service-National Sample Cohort of Korea; this sample was followed up from January 1, 2002, until the date of CRC incidence, loss to follow-up, or December 31, 2015. The exposure status of cholecystectomy and appendectomy was treated as a time-varying covariate. The calculated risk of CRC was stratified by follow-up period, and the association between these surgical procedures and CRC was investigated by a Cox regression model applying appropriate lag periods. Results: A total of 707 663 individuals were identified for analysis. The study population was followed up for an average of 13.66 years, and 4324 CRC cases were identified. The hazard ratio (HR) of CRC was elevated in the first year after cholecystectomy (HR, 1.71; 95% confidence interval [CI], 1.01 to 2.89) and in the first year and 2-3 years after appendectomy (HR, 4.22; 95% CI, 2.87 to 6.20; HR, 2.34; 95% CI, 1.36 to 4.03, respectively). The HRs of CRC after applying 1 year of lag after cholecystectomy and 3 years of lag after appendectomy were 0.80 (95% CI, 0.57 to 1.13) and 0.77 (95% CI, 0.51 to 1.16), respectively. Conclusions: The risk of CRC increased in the first year after cholecystectomy and appendectomy, implying the possibility of bias. When appropriate lag periods after surgery were applied, no association was found between cholecystectomy or appendectomy and CRC.

기업의 생존요인 연구 : 국내 소프트웨어 기업을 중심으로 (A Study on Firm Survival Factors : Focusing on Korean Software Firms)

  • 박강민;김준연
    • 기술혁신연구
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    • 제26권4호
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    • pp.98-121
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    • 2018
  • 본 연구는 콕스회귀분석과 누적한계추정법으로 1995년부터 2015년까지 1,084개의 국내 소프트웨어 기업을 분석하고, 생존율과 생존의 결정요인을 밝히는 것이다. 분석 결과 생존율의 경우, IT서비스, 패키지 소프트웨어, 게임 소프트웨어, 인터넷 서비스 각 분야별로 다른 형태를 보였다. 또한 연구개발 투자와 기업의 매출액 및 자산증가율로 나타나는 성장성은 생존에 긍정적이었으며, 여유자원은 부정적인 영향을 미쳤으며, 나이와 규모는 그 영향을 찾을 수 없었다. 이러한 결과는 소프트웨어 기업의 생존 전략과 정부의 지원 정책에 있어서 산업과 기술의 특성을 고려해야 한다는 점을 시사한다. 본 연구는 90년대 말 외환위기라는 특수 상황이나 제조업 중심으로 진행된 국내 생존분석의 영역을 최근 중요성이 커지는 소프트웨어 산업으로 확장했다는 의미가 있다.

300인 미만 사업장근로자의 6개월 이내 재흡연 관련요인 (Factors Related to Smoking Recurrence within Six-months Smoking Cessation among Employees in Enterprises with Smaller than 300 Workers)

  • 진병준;김철웅;이승은;임효빈;이태용
    • 지역사회간호학회지
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    • 제32권1호
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    • pp.107-115
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    • 2021
  • Purpose: The purpose of this study is to identify factors associated with smoking relapse within six months after quit attempts among workers in small and medium-sized enterprises in South Korea. Methods: The analysis was conducted for a total of 194 people who attempted to quit smoking by applying for a smoking cessation support service at the Regional Tobacco Control Center. The data used in the study were extracted from the Smoking Cessation Service Integrated Information System. Kaplan-Meier estimator and Cox proportional hazards regression model were used to identify variables associated with smoking relapse within six months' time period. Results: Smoking relapse rate within six months was 66.0%, and variables associated with relapse included the cases such as carbon monoxide (CO) at the time of registration (HR: 2.15, 95% CI: 1.10~4.22 for CO ≥20 ppm or more vs.CO <10 ppm), the average number of cigarettes smoked per day (HR: 1.04, 95% CI: 1.00~1.07), and the number of counseling(HR: 0.60, 95% CI: 0.54~0.67). Conclusion: Smoking characteristics and counseling showed one of the strongest correlations with relapse within six months. This implies that it is necessary to understand the smoking characteristics and patterns of workers and to provide continuous smoking cessation counseling tailored to individual characteristics for effective smoking relapse prevention.

Prognostic Role of Circulating Tumor Cells in the Pulmonary Vein, Peripheral Blood, and Bone Marrow in Resectable Non-Small Cell Lung Cancer

  • Lee, Jeong Moon;Jung, Woohyun;Yum, Sungwon;Lee, Jeong Hoon;Cho, Sukki
    • Journal of Chest Surgery
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    • 제55권3호
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    • pp.214-224
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    • 2022
  • Background: Studies of the prognostic role of circulating tumor cells (CTCs) in early-stage non-small cell lung cancer (NSCLC) are still limited. This study investigated the prognostic power of CTCs from the pulmonary vein (PV), peripheral blood (PB), and bone marrow (BM) for postoperative recurrence in patients who underwent curative resection for NSCLC. Methods: Forty patients who underwent curative resection for NSCLC were enrolled. Before resection, 10-mL samples were obtained of PB from the radial artery, blood from the PV of the lobe containing the tumor, and BM aspirates from the rib. A microfabricated filter was used for CTC enrichment, and immunofluorescence staining was used to identify CTCs. Results: The pathologic stage was stage I in 8 patients (20%), II in 15 (38%), III in 14 (35%), and IV in 3 (8%). The median number of PB-, PV-, and BM-CTCs was 4, 4, and 5, respectively. A time-dependent receiver operating characteristic curve analysis showed that PB-CTCs had excellent predictive value for recurrence-free survival (RFS), with the highest area under the curve at each time point (first, second, and third quartiles of RFS). In a multivariate Cox proportional hazard regression model, PB-CTCs were an independent risk factor for recurrence (hazard ratio, 10.580; 95% confidence interval, 1.637-68.388; p<0.013). Conclusion: The presence of ≥4 PB-CTCs was an independent poor prognostic factor for RFS, and PV-CTCs and PB-CTCs had a positive linear correlation in patients with recurrence.

자산빈곤이행 가능성에 영향을 미치는 요인에 관한 연구 (A Study on the Factors Affecting the Likelihood of the Asset Poor's Poverty Exit and Entry)

  • 강성민;유태균
    • 사회복지연구
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    • 제40권1호
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    • pp.115-138
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    • 2009
  • 본 연구의 목적은 자산빈곤층의 특성을 이해하고 자산빈곤이행(移行) 가능성에 영향을 미치는 요인을 실증적으로 알아보는 것이다. 이를 위해 본 연구에서는 한국노동패널자료를 분석자료로 이용하여 생존분석을 실시하였다. 자료분석 결과, 자산빈곤가구는 소득빈곤가구에 비해 빈곤지속기간이 길고, 빈곤탈피율이 낮으며 빈곤에 더 오래 머물러 있을 가능성이 높은 것으로 나타났다. 또한 시간의존 콕스회귀분석 결과, 가구주의 교육수준이 높고 소득 수준이 높으며, 비정규직에 비해 정규직일수록 자산빈곤을 조기에 탈피할 확률이 높은 것으로 나타났다. 이러한 연구결과를 바탕으로 기존의 빈곤정책과 함께 자산빈곤층의 자산을 형성하기 위한 제도적 지원이 필요하며, 국내에서 자산형성 지원사업이 시행이 된다면 좀 더 높은 수준의 교육을 받거나, 직무 능력 향상을 통해 안정적인 일자리(decent job)를 얻는 능력을 갖추는데 정책의 초점이 맞추어져야 할 것임을 제안한다.

Retrospective study of fracture survival in endodontically treated molars: the effect of single-unit crowns versus direct-resin composite restorations

  • Kanet Chotvorrarak;Warattama Suksaphar;Danuchit Banomyong
    • Restorative Dentistry and Endodontics
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    • 제46권2호
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    • pp.29.1-29.11
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    • 2021
  • Objectives: This study was conducted to compare the post-fracture survival rate of endodontically treated molar endodontically treated teeth (molar ETT) restored with resin composites or crowns and to identify potential risk factors, using a retrospective cohort design. Materials and Methods: Dental records of molar ETT with crowns or composite restorations (recall period, 2015-2019) were collected based on inclusion and exclusion criteria. The incidence of unrestorable fractures was identified, and molar ETT were classified according to survival. Information on potential risk factors was collected. Survival rates and potential risk factors were analyzed using the Kaplan-Meier log-rank test and Cox regression model. Results: The overall survival rate of molar ETT was 87% (mean recall period, 31.73 ± 17.56 months). The survival rates of molar ETT restored with composites and crowns were 81.6% and 92.7%, reflecting a significant difference (p < 0.05). However, ETT restored with composites showed a 100% survival rate if only 1 surface was lost, which was comparable to the survival rate of ETT with crowns. The survival rates of ETT with composites and crowns were significantly different (97.6% vs. 83.7%) in the short-term (12-24 months), but not in the long-term (> 24 months) (87.8% vs. 79.5%). Conclusions: The survival rate from fracture was higher for molar ETT restored with crowns was higher than for ETT restored with composites, especially in the first 2 years after restoration. Molar ETT with limited tooth structure loss only on the occlusal surface could be successfully restored with composite restorations.

Vaccination Status and In-hospital Mortality Among Adults With COVID-19 in Jakarta, Indonesia: A Retrospective Hospital-based Cohort Study

  • Hotma Martogi Lorensi Hutapea;Pandji Wibawa Dhewantara;Anton Suryatma;Raras Anasi;Harimat Hendarwan;Mondastri Korib Sudaryo;Dwi Gayatri
    • Journal of Preventive Medicine and Public Health
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    • 제56권6호
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    • pp.542-551
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    • 2023
  • Objectives: Prospective studies on vaccination status and mortality related to coronavirus disease 2019 (COVID-19) in low-resource settings are still limited. We assessed the association between vaccination status (full, partial, or none) and in-hospital mortality among COVID-19 patients at most hospitals in Jakarta, Indonesia during the Delta predomination wave. Methods: We conducted a retrospective cohort study among hospitalized COVID-19 patients who met the study criteria (>18 years old and admitted for inpatient treatment because of laboratory-confirmed severe acute respiratory syndrome coronavirus 2 infection). We linked individual-level data in the hospital admission database with vaccination records. Several socio-demographic and clinical characteristics were also analyzed. A Cox proportional hazards regression model was used to explore the association between vaccination status and in-hospital mortality in this patient group. Results: In total, 40 827 patients were included in this study. Of these, 70% were unvaccinated (n=28 543) and 19.3% (n=7882) died during hospitalization. The mean age of the patients was 49 years (range, 35-59), 53.2% were female, 22.0% had hypertension, and 14.2% were treated in the intensive care unit, and the median hospital length of stay across the group was 9 days. Our study showed that the risk of in-hospital mortality among fully and partially vaccinated patients was lower than among unvaccinated adults (adjusted hazard ratio [aHR], 0.43; 95% confidence interval [CI], 0.40 to 0.47 and aHR, 0.70; 95% CI, 0.64 to 0.77, respectively). Conclusions: Vaccinated patients had fewer severe outcomes among hospitalized adults during the Delta wave in Jakarta. These features should be carefully considered by healthcare professionals in treating adults within this patient group.

Prognostic Value of Dual-Energy CT-Based Iodine Quantification versus Conventional CT in Acute Pulmonary Embolism: A Propensity-Match Analysis

  • Dong Jin Im;Jin Hur;Kyunghwa Han;Young Joo Suh;Yoo Jin Hong;Hye-Jeong Lee;Young Jin Kim;Byoung Wook Choi
    • Korean Journal of Radiology
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    • 제21권9호
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    • pp.1095-1103
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    • 2020
  • Objective: The present study aimed to investigate whether quantitative dual-energy computed tomography (DECT) parameters offer an incremental risk stratification benefit over the CT ventricular diameter ratio in patients with acute pulmonary embolism (PE) by using propensity score analysis. Materials and Methods: This study was conducted on 480 patients with acute PE who underwent CT pulmonary angiography (CTPA) or DECT pulmonary angiography (DE CT-PA). This propensity-matched study population included 240 patients with acute PE each in the CTPA and DECT groups. Altogether, 260 (54.1%) patients were men, and the mean age was 64.9 years (64.9 ± 13.5 years). The primary endpoint was all-cause death within 30 days. The Cox proportional hazards regression model was used to identify associations between CT parameters and outcomes and to identify potential predictors. Concordance (C) statistics were used to compare the prognoses between the two groups. Results: In both CTPA and DECT groups, right to left ventricle diameter ratio ≥ 1 was associated with an increased risk of all-cause death within 30 days (hazard ratio: 3.707, p < 0.001 and 5.573, p < 0.001, respectively). However, C-statistics showed no statistically significant difference between the CTPA and DECT groups for predicting death within 30 days (C-statistics: 0.759 vs. 0.819, p = 0.117). Conclusion: Quantitative measurement of lung perfusion defect volume by DECT had no added benefit over CT ventricular diameter ratio for predicting all-cause death within 30 days.

A retrospective study of the long-term survival of RESTORE® dental implants with resorbable blast media surface

  • Keun-Soo Ryoo;Pil-Jong Kim;Sungtae Kim;Young-Dan Cho;Young Ku
    • Journal of Periodontal and Implant Science
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    • 제53권6호
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    • pp.444-452
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    • 2023
  • Purpose: The aim of this study was to retrospectively evaluate the survival and failure rates of RESTORE® implants over a follow-up period of 10-15 years at a university dental hospital and to investigate the factors affecting the survival rate of these dental implants. Methods: A total of 247 RESTORE® dental implants with a resorbable blast media (RBM) surface inserted in 86 patients between March 2006 and April 2011 at the Department of Periodontology of Seoul National University Dental Hospital were included. Patients with follow-up periods of less than 10 years were excluded, and data analysis was conducted based on dental records and radiographs. Results: Over a 10- to 15-year period, the cumulative survival rate of the implants was 92.5%. Seventeen implants (6.88%) were explanted due to implant fracture (n=10, 4.05%), peri-implantitis (n=6, 2.43%), and screw fracture (n=1, 0.4%). The results of univariate regression analysis using a Cox proportional hazards model demonstrated that implants placed in male patients (hazard ratio [HR], 4.542; 95% confidence interval [CI], 1.305-15.807; P=0.017) and implants that supported removable prostheses (HR, 15.498; 95% CI, 3.105-77.357; P=0.001) showed statistically significant associations with implant failure. Conclusions: Within the limitations of this retrospective study, the RESTORE® dental implant with an RBM surface has a favorable survival rate with stable clinical outcomes.

Reduced risk of gastrointestinal bleeding associated with eupatilin in aspirin plus acid suppressant users: nationwide population-based study

  • Hyun Seok Lee;Ji Hyung Nam;Dong Jun Oh;Yeo Rae Moon;Yun Jeong Lim
    • The Korean journal of internal medicine
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    • 제39권2호
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    • pp.261-271
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    • 2024
  • Background/Aims: Mucoprotective agents, such as eupatilin, are often prescribed to prevent gastrointestinal (GI) bleeding in addition to an acid suppressant despite the absence of a large-scale study. We evaluated the additional effect of eupatilin on the prevention of GI bleeding in both the upper and lower GI tract in concomitant aspirin and acid suppressant users using the nationwide database of national claims data from the Korean National Health Insurance Service (NHIS). Methods: An aspirin cohort was constructed using the NHIS claims data from 2013 to 2020. Patients who manifested with hematemesis, melena, or hematochezia were considered to have GI bleeding. A Cox proportional hazards regression model was used to determine the risk factors for GI bleeding associated with the concomitant use of GI drugs and other covariates among aspirin users. Results: Overall, a total of 432,208 aspirin users were included. The concurrent use of an acid suppressant and eupatilin (hazard ratio [HR] = 0.85, p = 0.016, vs. acid suppressant only) was a statistically significant preventive factor for GI bleeding. Moreover, a more than 3-month duration (HR = 0.88, p = 0.030) of acid suppressant and eupatilin prescription (vs. acid suppressant only) was a statistically significant preventive factor for GI bleeding. Conclusions: Eupatilin administration for ≥ 3 months showed additional preventive effect on GI bleeding in concomitant aspirin and acid suppressant users. Thus, cotreatment with eupatilin with a duration of 3 months or longer is recommended for reducing GI bleeding among aspirin plus acid suppressant users.