• Title/Summary/Keyword: case-control studies

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Approaches to the Analysis of Case-Control Studies of the Efficacy of Screening for Cancer

  • Weiss Noel S.;Mcknight Barbara;Stevens Nancy G.
    • 대한예방의학회:학술대회논문집
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    • 1994.02b
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    • pp.188-195
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    • 1994
  • To an increasing extent, case-control studies are being undertaken to determine if use of early detection procedures is associated with reduced mortality from cancer. The authors recommend that in such studies the analysis focus on screening activity in cases that occurs during an interval prior to diagnosis in which the cancer is believed to be detectable and still curable and to a corresponding time period in controls. This approach places a heavy burden on the investigator to estimate accurately the period during which the tumor ought to be detectable using the test in question and to sort out reliably tests done in response to signs or symptoms of the cancer from screening tests per se. Nonetheless, the authors feel that it offers the greatest ability to discern a true benefit of screening, while minimizing the numerous potential biases that can be present in this type of study.

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Chronic Hepatitis B Virus Infection and Risk of Pancreatic Cancer: A Meta-analysis

  • Li, Lei;Wu, Bo;Yang, Li-Bo;Yin, Guan-Cheng;Liu, Ji-Yong
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.1
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    • pp.275-279
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    • 2013
  • Objectives: A number of studies have shown that chronic hepatitis B virus infection is implicated in susceptibility to pancreatic cancer. However, the results are still controversial. This meta-analysis aimed to quantitatively assess the relationship between chronic hepatitis B virus infection and incidence of pancreatic cancer of cohort and case-control studies. Methods: A literature search was performed for entries from 1990 to 2012 using PUBMED and EMBASE. Studies were included if they reported odds ratios (ORs) and corresponding 95% CIs of pancreatic cancer with respect to the infection of hepatitis B virus. Results: Eight studies met the inclusion criteria, which included five case-control studies and three cohort studies. Compared with individuals who have not infection of hepatitis B virus, the pooled OR of pancreatic cancer was 1.403 (95%CI: 1.139-1.729, P=0.001) for patients with hepatitis B virus infection. Sub-group analysis by study design showed that the summary OR was 1.43 (95%CI: 1.06-1.94, P=0.021) when pooling case-control studies and 1.31 (95%CI: 1.00-1.72, P=0.05) when pooling cohort studies. Conclusion: Findings from this meta-analysis suggest that chronic hepatitis B virus infection may increase the risk of pancreatic cancer. This relationship needs to be confirmed by further follow-up studies.

Homogeneity in Case/Control Numbers and North Indian Caste Criteria in Cervical Cancer/Female Urology Genetic-Studies at a Premier Medical Research Institute in Lucknow, India

  • Pandey, Saumya;Chandravati, Chandravati
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.10
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    • pp.6185-6187
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    • 2013
  • Cervical cancer has emerged as a major public health problem in Lucknow and New York in the $21^{st}$ century. Cancer genetic studies are essential to identify/stratify disease-susceptible individuals in a population-based cohort. Sample size homogeneity and North Indian caste in female urology genetic-studies are significant issues in meaningful interpretation of data. A review of scientific literature using Pubmed database was conducted, including an assessment of cervical cancer genetic studies conducted as part of the author's doctoral dissertation at a premier Lucknow-based medical research Institute. Sample size numbers and caste criteria in the North Indian cohort ($N{\leq}400$ subjects) were evaluated with homogeneity in the sample cohort data set(s). Subgroup caste-stratification of North Indian cohort is equally essential, for instance, Brahmin (e.g. Pandey), Vaishya (e.g. Mittal), Rajput (e.g. Singh) and Kshudra (e.g. Yadav) during the conception and design of genetics-based studies. Sample size homogeneity in histopathologically confirmed case and control numbers and caste-based stratification in a North Indian cohort is essential in single nucleotide polymorphism (SNP) studies in cervical cancer susceptible populations to draw more definitive conclusions.

Analysis of Nested Case-Control Study Designs: Revisiting the Inverse Probability Weighting Method

  • Kim, Ryung S.
    • Communications for Statistical Applications and Methods
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    • v.20 no.6
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    • pp.455-466
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    • 2013
  • In nested case-control studies, the most common way to make inference under a proportional hazards model is the conditional logistic approach of Thomas (1977). Inclusion probability methods are more efficient than the conditional logistic approach of Thomas; however, the epidemiology research community has not accepted the methods as a replacement of the Thomas' method. This paper promotes the inverse probability weighting method originally proposed by Samuelsen (1997) in combination with an approximate jackknife standard error that can be easily computed using existing software. Simulation studies demonstrate that this approach yields valid type 1 errors and greater powers than the conditional logistic approach in nested case-control designs across various sample sizes and magnitudes of the hazard ratios. A generalization of the method is also made to incorporate additional matching and the stratified Cox model. The proposed method is illustrated with data from a cohort of children with Wilm's tumor to study the association between histological signatures and relapses.

Body Mass Index Effects on Risk of Ovarian Cancer: A Meta-Analysis

  • Poorolajal, Jalal;Jenabi, Ensiyeh;Masoumi, Seyyedeh Zahra
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.18
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    • pp.7665-7671
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    • 2014
  • Objectives: The association between body mass index (BMI) and ovarian cancer risk is unclear and requires further investigation. The present meta-analysis was conducted to assess the effect of overweight and obesity on ovarian cancer risk in the premenopausal and postmenopausal periods. Data sources: Major electronic databases were searched until February 2014 including Medline and Scopus. Reference lists and relevant conference databases were searched and the authors were contacted for additional unpublished references. Review Methods: All cohort and case-control studies addressing the effect of BMI on ovarian cancer were included, irrespective of publication date and language. The effect measure of choice was risk ratio (RR) for cohort studies and odds ratio (OR) for case-control studies. The results were reported using a random effects model with 95% confidence intervals (CIs). Results: Of 3,776 retrieved studies, 19 were ultimately analyzed including 10 cohort studies involving 29,237,219 person-years and 9 case-control studies involving 96,965 people. The results of both cohort and case-control studies showed being overweight and obesity increased the risk of ovarian cancer compared to women with normal weight during both premenopausal and postmenopausal periods: RR=1.08 (95%CI: 0.97, 1.19) and OR=1.26 (95%CI: 0.97, 1.63) for overweight and RR=1.27 (95%CI: 1.16, 1.38) and OR=1.26 (95%CI: 1.06, 1.50) for obesity. Conclusions: There is sufficient evidence that an increase in BMI can increase the risk of ovarian cancer regardless of the menopausal status, mimicking a dose-response relationship although the association is not very strong.

Acupuncture for Parkinson's Disease in China (중국에서의 파킨슨병 침치료 임상연구 동향)

  • Kim, Lak-Hyung;Jang, In-Soo;Kang, Sei-Young
    • Korean Journal of Acupuncture
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    • v.28 no.4
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    • pp.147-158
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    • 2011
  • Objectives : The purpose of this study was to obtain some knowledge about the acupuncture treatments on Parkinson's disease for the future practice and the research from the clinical studies in China. Methods : The literatures were searched using the data base-China Academic Journals (CAJ) (1994-2011). Clinical studies of acupuncture for Parkinson's disease such as randomized controlled trial (RCT), non-randomized controlled trial (NRCT), case series, case report were included. Results : Of 145 articles, 52 Clinical studies met our inclusion criteria: 20 RCTs, 7 NRCTs, 22 case series and 3 case reports. Various kinds of acupuncture treatments such as scalp acupuncture, body acupuncture, abdominal acupuncture, acupoint injection, eye acupuncture and thick needle acupuncture (粗鍼) were used in the clinical studies. The treatment and control groups take Madopa Tablet (Levodopa + Benserazide HCl) in the same time in many studies, and Madopa treatment was used as a comparative treatment in the most of studies. Acupuncture treatment was done daily or 2~3 times a week for 2~20 weeks. All of studies reported high effective rate in the treatment group compared to control group. Conclusions : The results of this study could be used for the future study about the acupuncture therapy for Parkinson's disease.

A Review of Fire Needling on Frozen Shoulder: Focusing on Chinese Journals (동결견의 화침치료에 대한 임상논문 고찰: 중국논문을 중심으로)

  • Lee, Ji Su;Ryu, Chun Gil;Jeong, Seong Sik;Moon, Sung Il
    • Journal of Acupuncture Research
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    • v.30 no.3
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    • pp.87-99
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    • 2013
  • Objectives : The objective of this study is to find out the method and effects of fire needling on frozen shoulder in China. Methods : We searched journals using the China National Knowledge Infrastructure(CNKI) and PubMed. The keywords were a combination of "fire needling", "fire needle", "burning acupuncture", "frozen shoulder", "adhesive capsulitis", "periarthritis". Results : There were 23 studies finally selected, 7 were case control studies and 16 were case series studies. There were 9 out of 14 main meridians and 31 kinds of acupoints. The most frequently adopted meridians were LI, SI and TE. The most frequently used acupoints were $LI_{15}$, $SI_9$ and $TE_{14}$. Adjacent points were used more often than distant points. They usually heated the needle before insertion and needle retention was mostly not done. 7 case control studies showed that fire needling reported better results than the filiform needle or electro-acupuncture treatment. 15 case series studies reported a significant improvement in fire needling on frozen shoulder patients. Conclusions : There have been many studies regarding fire needling on frozen shoulder in China. Further studies should be required and these can be applied to clinical practices in Korea.

Research Trends on the Thread Embedding Therapy of Obesity in Traditional Chinese Medicine (매선 비만의 중의 연구 최신 경향)

  • Kim, Yoo-Jin;Shin, Mi-Sook
    • Korean Journal of Acupuncture
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    • v.30 no.3
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    • pp.151-160
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    • 2013
  • Objectives : The purpose of this study is to review the thread embedding treatment studies of obesity in Traditional Chinese Medicine. Methods : We reviewed 59 studies on cat-gut-embedding treatment of obesity which were published from 2005 to 2012. The studies were searched using the data base-CAJ(China Academic Journals; 中國期刊全文數據庫)(2005~2012). Results : Selected 59 studies were divided into 27 case series and 32 control studies. The number of studies has increased since 2005, more rapidly in 2011~2012. Most case series reported were about effectiveness of thread embedding monotherapy treating obesity. Control studies reported were about effectiveness of thread embedding treatment compared with acupuncture, electroacupuncture, and medicine. Most studies on thread embedding treatment of obesity showed that its effectiveness was very good. Conclusions : There have been many reports of thread embedding treatment studies of obesity in Traditional Chinese Medicine. We believed that these studies could be applied to the clinical practice and basic research in Korea.

The Review on the Domestic Studies of Moxibustion (최근 10년간 국내 뜸관련 연구에 대한 고찰)

  • Shin, Jung-Mi;Kang, Mi-Suk;Song, Ho-Sueb
    • Journal of Acupuncture Research
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    • v.26 no.5
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    • pp.117-125
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    • 2009
  • Objectives : This study is to research the trend of the Moxibustion-related studies and to establish the hereafter direction for the study on Moxibustion. Methods : We reviewed the domestic articles published last ten years(2000~2009). Results : We have searched 45 articles in 4 journals of Korean Acupuncture & Moxibusion, Korean Oriental Medicine, Korean Meridian & Acupoint, Korean Oriental Internal Medicine. 1. There were the most research done 2003, 2008. Both of them have 8 articles. In other years there were 2 or more articles. 2. The pattern of study was as follow: the clinical studies were 23, studies of phisical Characteristics and new moxibustion method were 9, the philological study were 5, the reviewed studies were 3, the experimental studies were 2 and the others were 5. The rate of clinical studies was increased. 3. In the clinical studies, the case-control study and non case-control study were more than case study. The disease after stroke were the most predominant. The rates of direct moxibustion and indirect moxibusion were similar. 4. After beginning 2000s, there were more studies of thermodynamic Characteristics. In the mid 2000s, there were more studies of new moxibustion method appearing. Conclusions : We need more studies about various kinds of diseases, side effect and aftereffects. There should be convenient and useful methods of moxibustion.

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The Controls of Client-Server System: Case Studies of Banks (클라이언트-서버 시스템에 대한 통제: 은행업체에 대한 사례연구)

  • 이상재
    • Korean Management Science Review
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    • v.17 no.2
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    • pp.97-113
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    • 2000
  • The introduction of client server systems raises some serious IS control concerns. Although client server systems increase system flexibility and compatibility, and facilitates system downsizing and process restructuring, multiple operating systems, database management systems, and platforms of client-server system increase th potential exposures and risks of the system. It is needed to recommend the effective control framework to mitigate risks. This paper suggests risks and control framework for client server system. The results of two case studies indicate that program and database management are important as program and data should be located and maintained in client and servers. It becomes difficult to manage divided programs and data logic that are distributed across clients and servers that have different platforms. The case studies of two banks show that the extent of distribution of program and data logic affects the importance of program and database management controls.

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