• Title/Summary/Keyword: Nested Factors

Search Result 70, Processing Time 0.041 seconds

A Nested Case-Control Study on the High Normal Blood Pressure as a Risk Factor of Hypertension in Korean Middle-aged Men (중년 남성에서 고정상혈압에 의한 고혈압발생 위험 규명을 위한 코호트내 환자-대조군 연구)

  • Ahn, Yoon-Ok;Bae, Jong-Myon
    • Journal of Preventive Medicine and Public Health
    • /
    • v.32 no.4
    • /
    • pp.513-525
    • /
    • 1999
  • Objectives : High-normal blood pressure' is a factor influencing decision to initiate targeted intensive intervention strategy in westernized populations. JNC-VI offered the vigorous lifestyle modification for persons with 'high-normal blood pressure', who could be early detected. As a hypertension seems to be the result of multiple genetic factors operating in concert with associated environmental factors, it will be necessary to identify the high-normal blood pressure as a risk factor of hypertension for applying primary prevention strategy in Korean people. Methods : Although cohort study design might be adequate to recruit incidence cases, to keep time sequence of events, and to prevent information bias, nested case-control study was chosen for avoiding measurement errors because hypertension is a benign disease. Source population was the 'Seoul Cohort' participants and follow-up was done by using Korea Medical Insurance Corporation's database on the utilization of health services from 1 Jan93 to 30Jun97. Incidence cases were ascertained through the chart review, telephone contacts, and direct blood pressure measurements. Controls included the pairing of 4 individuals to each case on the basis of age. Results : As 75% of 247 incident cases had high-normal blood pressure, the crude odds ratio for hypertension was 2.04 (95% CI 1.47-2.83). Another statistically significant risk factors of hypertension were body mass index, dietary fiber, alcohol consumption, weekly activity and history of quitting smoking. The multivariate odds ratio of high-normal blood pressure adjusted for all risk factors was 1.84 (95% CI 1.31-2.56). Among high-normal blood pressure group, body mass index, weekly ethanol amounts, weekly physical activity, and dietary fiber except history of quitting smoking were still risk factors of hypertension. Conclusion : 'High-normal blood pressure' is a risk factor for hypertension in Korean middle-aged men, which represents that the vigorous lifestyle modification for persons with 'high-normal blood pressure' is need.

  • PDF

Month and Season of Birth as a Risk Factor for Alzheimer's Disease: A Nationwide Nested Case-control Study

  • Tolppanen, Anna-Maija;Ahonen, Riitta;Koponen, Marjaana;Lavikainen, Piia;Purhonen, Maija;Taipale, Heidi;Tanskanen, Antti;Tiihonen, Jari;Tiihonen, Miia;Hartikainen, Sirpa
    • Journal of Preventive Medicine and Public Health
    • /
    • v.49 no.2
    • /
    • pp.134-138
    • /
    • 2016
  • Objectives: Season of birth, an exogenous indicator of early life environment, has been related to higher risk of adverse psychiatric outcomes but the findings for Alzheimer's disease (AD) have been inconsistent. We investigated whether the month or season of birth are associated with AD. Methods: A nationwide nested case-control study including all community-dwellers with clinically verified AD diagnosed in 2005 to 2012 (n=70 719) and up to four age- sex- and region of residence-matched controls (n=282 862) residing in Finland. Associations between month and season of birth and AD were studied with conditional logistic regression. Results: Month of birth was not associated with AD (p=0.09). No strong associations were observed with season (p=0.13), although in comparison to winter births (December-February) summer births (June-August) were associated with higher odds of AD (odds ratio, 1.03; 95% confidence interval, 1.00 to 1.05). However, the absolute difference in prevalence in winter births was only 0.5% (prevalence of those born in winter were 31.7% and 32.2% for cases and controls, respectively). Conclusions: Although our findings do not support the hypothesis that season of birth is related to AD/dementia risk, they do not invalidate the developmental origins of health and disease hypothesis in late-life cognition. It is possible that season does not adequately capture the early life circumstances, or that other (postnatal) risk factors such as lifestyle or socioeconomic factors overrule the impact of prenatal and perinatal factors.

A Nested Case Control Study on Risk Factors for Coronary Heart Disease in Korean (관상동맥질환 위험요인 구명을 위한 코호트내 환자-대조군 연구)

  • Kim, Ki-Soon;Park, Jong;Park, Jong-Ku;Kim, Chun-Bae;Chun, Byung-Yeol;Lee, Tae-Yong;Lee, Kang-Sook;Lee, Duk-Hee;Koh, Kwang-Wook;Jee, Sun-Ha;Suh, Il;Ryu, So-Yeon
    • Journal of Preventive Medicine and Public Health
    • /
    • v.34 no.2
    • /
    • pp.149-156
    • /
    • 2001
  • Objective : To elucidate risk factors for coronary heart diseases among Korean males. Methods : A nested case control study was conducted among a Korea Medical Insurance Cooperation(KMIC) cohort composed of 108,802 males. The eases included 246 male patients who were admitted to hospital due to coronary heart diseases from 1993 to 1997 (120-25 by ICD) and whose diagnosis was confirmed by the protocol by WHO MONICA Project(1994). The control group was composed of 483 patients selected by frequency matching considering age and resident area from an inpatient care group without coronary heart disease during the same period. For study cases and the controls, the results of a health check-up in 1990 and a questionnaire on life style in 1992 were received through the KMIC. Some additional information was collected by telephone interviews during October 1999. Results : Multiple logistic regression analysis showed that the odds ratio(OR) of coronary heart diseases among past smokers and current smokers as compared to non-smokers were 1.94(95% CI : 1.14-3.31) and 2.20(55% CI : 1.35-3.59), respectively. The OR among persons who drank 4 cups or more of caffeinated beverages such as coffee or tea daily as compared to persons who drank one cup for 2-3 days was 2.50(95% CI : 1.07-6.12). The OR among persons with high normal BP and stage 3 hypertension against normotension were 2.51 (95% CI : 1.44-4.37) and 5.08(95% CI : 2.38-10.84). The OR among persons whose blood cholesterol were 240 mg/dL or mere against lower than 200mg/dL was 2.24(95% CI : 1.43-3.49). Conclusion : Smoking, drinking of excessive caffeinated beverages, hypertension and high blood cholesterol were proven to be significant risk factors for coronary heart diseases among Korean males.

  • PDF

A dominant hyperrectangle generation technique of classification using IG partitioning (정보이득 분할을 이용한 분류기법의 지배적 초월평면 생성기법)

  • Lee, Hyeong-Il
    • Journal of the Korea Society of Computer and Information
    • /
    • v.19 no.1
    • /
    • pp.149-156
    • /
    • 2014
  • NGE(Nested Generalized Exemplar Method) can increase the performance of the noisy data at the same time, can reduce the size of the model. It is the optimal distance-based classification method using a matching rule. NGE cross or overlap hyperrectangles generated in the learning has been noted to inhibit the factors. In this paper, We propose the DHGen(Dominant Hyperrectangle Generation) algorithm which avoids the overlapping and the crossing between hyperrectangles, uses interval weights for mixed hyperrectangles to be splited based on the mutual information. The DHGen improves the classification performance and reduces the number of hyperrectangles by processing the training set in an incremental manner. The proposed DHGen has been successfully shown to exhibit comparable classification performance to k-NN and better result than EACH system which implements the NGE theory using benchmark data sets from UCI Machine Learning Repository.

Nested Multiplex PCR Based Detection of Human Papillomavirus in Cervical Carcinoma Patients of North- East India

  • Das, Debabrata;Rai, Avdhesh Kumar;Kataki, Amal Chandra;Barmon, Debabrata;Deka, Pankaj;Sharma, Jagannath Dev;Sarma, Anupam;Shrivastava, Sushruta;Bhattacharyya, Mouchumee;Kalita, Apurba Kumar;Sharma, Mousumi;Ahmed, Shiraj
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.14 no.2
    • /
    • pp.785-790
    • /
    • 2013
  • Background: Persistent infection of one or more of about 15 high-risk human papillomaviruses (HR-HPVs), most commonly HPV types 16/18, has a significant role in cervical cancer initiation and progression. There are limited data available from north-east India about HPV prevalence though this region has high incidence rates of cervical cancer. The aim of this study was to investigate the HPV genotypes prevalent in cervical cancer patients of north-east India. Materials and Methods: We analyzed 107 cervical cancer patient samples. Nested multiplex PCR assays were employed for detection of 13 high risk and 5 low risk HPV types. Results: HPV was confirmed in 105 samples. The presence of 6 'carcinogenic' HPV types, HPV-16 (88%), -18 (15%), -31(4%),-45 (3%), -59 (4%), -58(1%), and one non carcinogenic, HPV-6/11 (6%), was recorded. Among various demographic and clinical factors only tumour stage showed a statistically significant association with HPV type infection (P=0.019). Conclusions: We suggest that the most prevalent genotype is HPV-16 followed by HPV-18 in cervical carcinoma patients of the north-eastern region of India. Advanced tumour stage may be associated with increased possibility of harbouring multiple HPV genotypes.

A Marginal Probability Model for Repeated Polytomous Response Data

  • Choi, Jae-Sung
    • Journal of the Korean Data and Information Science Society
    • /
    • v.19 no.2
    • /
    • pp.577-585
    • /
    • 2008
  • This paper suggests a marginal probability model for analyzing repeated polytomous response data when some factors are nested in others in treatment structures on a larger experimental unit. As a repeated measures factor, time is considered on a smaller experimental unit. So, two different experiment sizes are considered. Each size of experimental unit has its own design structure and treatment structure, and the marginal probability model can be constructed from the structures for each size of experimental unit. Weighted least squares(WLS) methods are used for estimating fixed effects in the suggested model.

  • PDF

The Relationship between Burning Mouth Syndrome and Helicobacter pylori in the Oral Cavity (구강작열감증후군과 구강 내 Helicobacter pylori의 상호관련성)

  • Kim, Jun-Ho;Ryu, Ji-Won;Yoon, Chang-Lyuk;Ahn, Jong-Mo
    • Journal of Oral Medicine and Pain
    • /
    • v.36 no.2
    • /
    • pp.91-97
    • /
    • 2011
  • Helicobacter pylori (H. pylori) is bacterial infection, with more than half of the world population infected and relates to many oral disease such oral lichen planus, recurrent aphthous ulceration, periodontal disease and halitosis and so on. Burning mouth syndrome(BMS) is defined as a burning sensation of the oral mucosa, lips, and/or tongue, in the absence of specific oral lesions. The etiology of BMS is suggested local, systemic and psychological factors and researchs related BMS and to infection of H. pyloir in the oral cavity are few. The purpose of this study was to evaluate relationship between burning mouth syndrome and H. pylori in the oral cavity. We recruited 21 subjects with burning mouth syndrome and 21 subjects as control group. Samples in the oral cavity were taken area of buccal mucosa, dorsum of the tongue and saliva. We analysed samples by nested polymerase chain reaction(PCR). The results were as follows: 1. Among 21 patients with burning mouth sydrome and 21 subjects of control group, 6(29%) and 3(14%) were positive respectively(P>0.05). 2. In detection rate of H. pylori in area taken sample, 3(14%), 2(10%) and 4(19%) were positive in buccal mucosa, dorsum of the tongue and saliva of patient and 2(10%) and 1(5%) were positive in dorsum of the tongue and saliva of control group(P>0.05). Conclusively, we can guess that H. pylori in the oral cavity is not related with burning mouth syndrome.

Efficacy of In-Ovo Vaccination against Marek's Disease in Commercial Broiler (마렉백신의 In-Ovo 접종에 따른 육계에서의 효능 평가)

  • Um, H.J.;Won, M.Y.;Lee, D.W.;Go, D.W.;Mo, I.P.
    • Korean Journal of Poultry Science
    • /
    • v.33 no.4
    • /
    • pp.295-301
    • /
    • 2006
  • This study has been designed to evaluate the efficacy of MD in-ovo vaccination in broiler and to find the contamination level of MD virus in broiler farms. A nested PCR test was used to find the level of filed contamination of pathogenic MD virus in the commercial broiler farms. The positive rate of farms contaminated with pathogenic MD virus was 26.09%. And to evaluate the efficacy of MD vaccination, performance factors such as the mortality, feed conversion rate and body weight at market age has been recorded and compared among farms. There was no difference on these factors between vaccinated and non-vaccinated farms except performance. We need further investigation of the film with low performance index. The B/B ratio, which is common index for the evaluation of bursal changes, was calculated and compared between vaccinated and non-vaccinated group There were significant decreases of B/B ratio in the both group without any statistical difference between groups. The reason of decreased bursal size may be due to other infection such as IBD. From this study, we can know that the contamination rate of fm with pathogenic MD virus was very low and not different from previous study. However, the difference of the contamination rate in different locations recommends periodical monitoring on these areas.

Risk Factors of Breast Cancer in the Eastern Mediterranean Region: A Systematic Review and Meta-Analysis

  • Namiranian, Nasim;Moradi-Lakeh, Maziar;Razavi-Ratki, Seid Kazem;Doayie, Mahdyie;Nojomi, Marzieh
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.21
    • /
    • pp.9535-9541
    • /
    • 2014
  • Background: Identifying risk factors of breast cancer is a key point for preventive strategies to reduce the incidence. The aim of current study was to determine most important risk factors for breast cancer in the Eastern Mediterranean Region (EMR) using a systematic review. Materials and Methods: PubMed, Scopus, Web of Science till August 24, 2012 and the reference lists of all included studies were searched. Analytic studies which had reported odds ratios (OR), relative risk (RR) or required data to calculate them were included. A total of 343 studies were critically appraised and finally 30 studies were meta-analyzed. Heterogeneity between the studies was assessed by $I^2$ and Cochran's Q. Egger's test was used to assess publication bias. Results: Twenty five casecontrol studies, one nested case-control and four cohort studies were included. The largest ORs were obtained for history of no live birth (2.25; 95%CI: 1.58-3.18), body mass index (BMI) more than 30 (2.21; 95%CI: 1.71-2.36), age at first pregnancy more than 30 years old (1.52; 95%CI: 1.30-1.77) and meat consumption more than three times per week (1.39; 95%CI: 1.03-1.87). The other important predictors were higher education and smoking as risk factors, physical activity and ovulatory stimulating medication as protective factors. Conclusions: The most important predictors of breast cancer in EMR were history of no live birth, BMI more than 30, age at first pregnancy more than 30 years old, physical inactivity and smoking. Almost all these risk factors are consistent with known risk factors for this cancer in other parts of the world.