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991.
Objective:To assess whether the difference in risk of cardiovascular mortality between urban and rural areas of Serbia could be explained by differences in the use of cardiovascular medication.Methods: The Serbian cohorts of the Seven Countries Study, Velika Krsna (VK), Zrenjanin (ZR) and Belgrade (BG), were enrolled in 1962-1964 and were followed up for 25 years. The survivors of these cohorts were re-examined in 1987, 1988 and 1989, respectively. This second examination of elderly men aged 65 to 84 years included a questionnaire about current use of cardiovascular medication, risk factors and diseases and a physical examination. All subjects were followed until death or the predefined censor date (10 years after baseline). The Cox proportional hazards model was used to calculate the risk of cardiovascular mortality in the rural cohorts compared to the urban cohort and to adjust for confounding.Main outcome measure: Cardiovascular death. Results: A total of 227 men from VK, 184 men from ZR and 287 men from BG were followed for a mean duration of 7.4 years and was complete for all subjects. After exclusion of 13 subjects with missing medication data, the incidences of cardiovascular mortality in VK, ZR, and BG were 60, 74, and 26 per 1000 person-years, respectively. The prevalence of cardiovascular medication use was 38% in VK, 52% in ZR, and 59% in BG. The greatest difference in use of specific medication was observed for betablockers (0% in VK and ZR, 13% in BG). After adjustment for cardiovascular risk factors, diseases and age, the relative risks (RRs) of cardiovascular mortality were 2.12 [95% CI: 1.44–3.12], and 2.27 [95% CI: 1.56–3.30] in VK, and ZR compared to BG. Additional adjustment for the use of cardiovascular medication increased these RRs to 2.40 [95% CI: 1.61–3.60] and 2.55 [95% CI: 1.72–3.78], respectively.Conclusion:The variation in cardiovascular medication use could not explain the excess risk of mortality in the rural Serbian cohorts compared to urban Belgrade.  相似文献   
992.
A consecutive sample of 378 adults with asthma were assessed at a university asthma program and then interviewed 1 year later regarding their need for emergency department (E.D.) asthma treatment. The purpose of this prospective cohort study was to determine whether any of their initial features could predict their subsequent need for E.D. asthma treatment. At one year, a total of 73 of the subjects had attended emergency departments for asthma. On entry, the 73 subjects had demonstrated more self-reported lifestyle restriction from asthma and more hospital admissions E.D. visits for asthma as well as poorer asthma control or than had the 305 subjects who had not required E.D. asthma treatment since entry to the cohort. This study suggests that special attention should be paid to subjects with asthma that interferes with their lifestyle and to those who have needed hospital admission for asthma.  相似文献   
993.
Community intervention evaluations that measure changes over time may conduct repeated cross-sectional surveys, follow a cohort of residents over time, or (often) use both designs. Each survey design has implications for precision and cost. To explore these issues, we assume that two waves of surveys are conducted, and that the goal is to estimate change in behavior for people who reside in the community at both times. Cohort designs are shown to provide more accurate estimates (in the sense of lower mean squared error) than cross-sectional estimates if (1) there is strong correlation over time in an individual's behavior at time 0 and time 1, (2) relatively few subjects are lost to followup, (3) the bias is relatively small, and (4) the available sample size is not too large. Otherwise, a repeated cross-sectional design is more efficient. We developed methods for choosing between the two designs, and applied them to actual survey data. Owing to drop-outs and losses to followup, the cohort estimates were usually more biased than the cross-sectional estimates. The correlations over time for most of the variables studied were also high. In many instances the cohort estimate, although biased, is preferred to the relatively unbiased cross-sectional estimate because the mean squared error was smaller for the cohort than for the cross-sectional estimate. If these results are replicated in other data, they may result in guidelines for choosing a more efficient study design.  相似文献   
994.
Summary A cohort of all the men employed in a bus company was undertaken to elucidate possible adverse health effects of diesel exhaust exposure. The results showed that the most heavily exposed group (bus garage workers) had a fourfold increase in risk of dying from cardiovascular disease, even after correction for smoking, and allowing for at least 10 years of exposure and 15 years or more of induction-latency time. The findings are in accordance with the hypothesis of a possible connection between exposure to carbon monoxide and cardiovascular disease.  相似文献   
995.
《癌症》2016,(9):447-454
Background: Serum immunoglobulin A antibodies against Epstein–Barr virus (EBV), viral capsid antigen (VCA?IgA) and early antigen (EA?IgA), are used to screen for nasopharyngeal carcinoma (NPC) in endemic areas. However, their routine use has been questioned because of a lack of specificity. This study aimed to determine the distributions of different subtypes of antibody and to illustrate how the natural variation patterns affect the specificity of screening in non?NPC participants. Methods: The distribution of baseline VCA?IgA was analyzed between sexes and across 10?year age groups in 18,286 non?NPC participants using Chi square tests. Fluctuations in the VCA?IgA level were assessed in 1056 non?NPC participants with at least two retests in the first 5?year period (1987–1992) after the initial screening using the Kaplan–Meier method. Results: The titers of VCA?IgA increased with age (P < 0.001). Using a previous serological definition of high NPC risk, nasopharyngeal endoscopy and/or nasopharyngeal biopsy would be recommended in 55.5% of the non?NPC partici?pants with an initial VCA?IgA?positive status and in 20.6% with an initial negative status during the 5?year follow?up. However, seroconversions were common; 85.2% of the participants with a VCA?IgA?positive status at baseline con?verted to negative, and all VCA?IgA?negative participants changed to positive at least once during the 5?year follow?up. The EA?IgA status had a high seroconversion probability (100%) from positive to negative; however, it had a low probability (19.6%) from negative to positive. Conclusions: Age? and sex?specific cutoff titer values for serum anti?EBV antibodies as well as their specific titer fluc?tuation patterns should be considered when defining high NPC risk criteria for follow?up diagnostics and monitoring.  相似文献   
996.
The aim of the present study was to evaluate mastication, food selection and nutritional aspects in two groups of persons restored with fixed (FPD, N=44) and removable (RPD, N=40) partial dentures respectively. The subjects were part of a cohort study of 67–68-year-old men living in Malmö, Sweden. The two groups were very similar regarding social factors and the inclusion criteria were chosen so that the groups were very equal regarding oral factors, apart from the difference in fixed and removable partial dentures. The number of natural teeth, number of replaced teeth and occlusal contacts did not differ significantly between the two groups, nor did the distribution of maxillary and mandibular dentures. A comprehensive examination of several general health factors included a home interview of dietary habits. A clinical examination included a 20-minute oral examination with registration of number of teeth, FPDs, RPDs, and occlusal contacts. It also included masticatory tests: chewing gum colour mixing, chewing gum bolus shaping, and swallowing threshold (number of strokes to the first swallow of an almond). The consumption of hard and soft foods was revealed by the dietary interview as well as the intake of energy and some nutrients. There was a significant difference between the groups regarding the capacity to mix the two-coloured chewing gum, to shape the chewing gum bolus and in the consumption of hard foods. There was no difference in the swallowing threshold and the consumption of soft foods. The intake of energy and nutrients did not differ significantly between the groups. The differences in masticatory capacity found thus seem to have little, if any, effect on the factors of importance for general health. A reasonable explanation for the differences found is that artificial teeth that are well retained, such as FPDs, make more active chewing possible than do removable, and often somewhat loose-fitting partial dentures.  相似文献   
997.
ObjectivesFindings from studies investigating early childhood episodes of otitis media (OM) and developmental outcomes are inconclusive. This may in part be because large-scale prospective studies controlling for relevant confounding factors are sparse. The present study investigates associations between OM in early childhood and later behavioural and learning difficulties controlling for relevant confounding factors.MethodsThe study applied data from the Aarhus Birth Cohort's 10–12-year-old follow-up (N = 7578). Associations between retrospective parent-reported OM (no OM; 1–3 episodes of OM with/without tympanostomy tubes; 4+ OM episodes without tympanostomy tubes and; 4+ OM episodes with tympanostomy tubes) one the one hand, and parent- and teacher-reported scores on the Strengths and Difficulties Questionnaire (SDQ) and parent-reported academic difficulties on the other hand, were investigated. The following variables were controlled for: parental educational level, maternal and paternal school problems, parental post-natal smoking, breastfeeding, and age at which the child started walking. All analyses were stratified by gender.ResultsLarge differences in background characteristics were observed for the group of children with 4+ OM episodes with tympanostomy tubes compared to the no OM group. After controlling for relevant confounders, negative associations were consistently observed for the group of children with 4+ episodes of OM with tympanostomy tubes compared to the group of children without OM. This was particularly so for girls.ConclusionThe findings suggest an association between 4+ episodes of early OM with tympanostomy tubes and behavioural and learning difficulties later in childhood. The large inter-group differences, i.e. impact of residual and unmeasured confounding factors, may in part explain the observed associations and underline the need to include these in future studies.  相似文献   
998.
Loss of expression of the transforming growth factor beta type II receptor (TbetaRII) has been implicated as an important event in renal carcinogenesis; however, its role as a potential prognostic factor remains poorly understood. Using archived tumor samples and long-term follow-up on a cohort of 280 clear cell renal cell carcinoma (ccRCC) patients treated with surgery from 1980 to 1998, we evaluated the association of TbetaRII expression and cancer-specific survival in both a univariate and multivariate setting. Low tumor expression of TbetaRII is associated with a less aggressive tumor phenotype at time of surgery. Moreover, those patients with lower levels of TbetaRII expression experience better cancer-specific survival than patients with higher levels of TbetaRII expression (log rank P = .034). Based on a Cox proportional hazard model adjusting for age, patients with tumors showing low (hazard ratio, 0.49; 95% confidence interval, 0.27-0.88) and moderate (hazard ratio, 0.7; 95% confidence interval, 0.40-1.23) TbetaRII expression are at decreased risk of RCC death compared with patients with tumors having high levels of TbetaRII expression. Adjustment for well-known pathologic predictors of RCC outcome attenuates the association of TbetaRII expression and ccRCC survival. Of interest, the association with TbetaRII expression appears more pronounced among those patients with tumors showing less aggressive phenotypes. Data from this investigation are the first to suggest that loss of TbetaRII expression is associated with improved ccRCC patient survival, especially among those patients with less aggressive disease profiles at time of surgery.  相似文献   
999.
1000.
BackgroundMetformin and statins may have anticancer effects, with plausible cellular mechanisms. However, the association of these agents with the risk of colorectal cancer is unclear.Patients and MethodsThis was a retrospective cohort study on a large population (N = 316,317) of patients with type 2 diabetes. Data were obtained from the Diabetes in Finland database (FinDM). In a full cohort analysis, hazard ratios (HRs) with their 95% confidence intervals (CIs) for ever use versus never use were estimated using a multiple Poisson regression model. A nested case–control design within the cohort was used to examine the association of colon cancer (CC) with the defined daily dose of medication. The data were analyzed by conditional logistic regression. The analyses were adjusted for the patient’s age, sex, and duration of diabetes.ResultsIn total, 1351 CC cases were diagnosed during 1996-2011. The results revealed insufficient evidence for an association between metformin (HR, 1.01; 95% CI, 0.90-1.14), other oral antidiabetic medications (HR, 1.05; 95% CI, 0.93-1.19), insulin (HR, 1.02; 95% CI, 0.86-1.22), or statins (HR, 0.94; 95% CI, 0.84-1.05) and the incidence of CC in the full cohort analysis. The results from the case–control study were similar, with no consistent trend in the incidence of CC according to the cumulative dose of metformin or the other studied medications.ConclusionThis study found insufficient evidence for an association between metformin, insulin, other oral type 2 diabetes medications, or statins and the incidence of CC.  相似文献   
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