Prevalence of true vein graft aneurysms: implications for aneurysm pathogenesis.
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BACKGROUND: Circumstantial evidence suggests that arterial aneurysms have a different cause than atherosclerosis and may form part of a generalized dilating diathesis. The aim of this study was to compare the rates of spontaneous aneurysm formation in vein grafts performed either for popliteal aneurysms or for occlusive disease. The hypothesis was that if arterial aneurysms form a part of a systemic process, then the rates of vein graft aneurysms should be higher for patients with popliteal aneurysms than for patients with lower limb ischemia caused by atherosclerosis. METHODS: Infrainguinal vein grafting procedures performed from 1990 to 1995 were entered into a prospective audit and graft surveillance program. Aneurysmal change was defined as a focal increase in the graft diameter of 1.5 cm or greater, excluding false aneurysms and dilatations after graft angioplasty. RESULTS: During the study period, 221 grafting procedures were performed in 200 patients with occlusive disease and 24 grafting procedures were performed in 21 patients with popliteal aneurysms. Graft surveillance revealed spontaneous aneurysm formation in 10 of the 24 bypass grafts (42%) for popliteal aneurysms but in only 4 of the 221 grafting procedures (2%) that were performed for chronic lower limb ischemia. CONCLUSION: This study provides further evidence that aneurysmal disease is a systemic process, and this finding has clinical implications for the treatment of popliteal aneurysms. (+info)
The value of late computed tomographic scanning in identification of vascular abnormalities after abdominal aortic aneurysm repair.
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PURPOSE: The purpose of this study was to determine the prevalence of late arterial abnormalities after aortic aneurysm repair and thus to suggest a routine for postoperative radiologic follow-up examination and to establish reference criteria for endovascular repair. METHODS: Computed tomographic (CT) scan follow-up examination was obtained at 8 to 9 years after abdominal aortic aneurysm (AAA) repair on a cohort of patients enrolled in the Canadian Aneurysm Study. The original registry consisted of 680 patients who underwent repair of nonruptured AAA. When the request for CT scan follow-up examination was sent in 1994, 251 patients were alive and potentially available for CT scan follow-up examination and 94 patients agreed to undergo abdominal and thoracic CT scanning procedures. Each scan was interpreted independently by two vascular radiologists. RESULTS: For analysis, the aorta was divided into five defined segments and an aneurysm was defined as a more than 50% enlargement from the expected normal value as defined in the reporting standards for aneurysms. With this strict definition, 64.9% of patients had aneurysmal dilatation and the abnormality was considered as a possible indication for surgical repair in 13.8%. Of the 39 patients who underwent initial repair with a tube graft, 12 (30.8%) were found to have an iliac aneurysm and six of these aneurysms (15.4%) were of possible surgical significance. Graft dilatation was observed from the time of operation (median graft size of 18 mm) to a median size of 22 mm as measured by means of CT scanning at follow-up examination. Fluid or thrombus was seen around the graft in 28% of the cases, and bowel was believed to be intimately associated with the graft in 7%. CONCLUSION: Late follow-up CT scans after AAA repair often show vascular abnormalities. Most of these abnormalities are not clinically significant, but, in 13.8% of patients, the thoracic or abdominal aortic segment was aneurysmal and, in 15.4% of patients who underwent tube graft placement, one of the iliac arteries was significantly abnormal to warrant consideration for surgical repair. On the basis of these findings, a routine CT follow-up examination after 5 years is recommended. This study provides a population-based study for comparison with the results of endovascular repair. (+info)
Screening for colorectal cancer--United States, 1997.
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Colorectal cancer is the second leading cause of cancer-related deaths in the United States. During 1999, approximately 129,400 new cases of colorectal cancer will be diagnosed, and 56,600 persons will die from the disease. In 1996, the U.S. Preventive Services Task Force (USPSTF) recommended the use of specific screening tests (i.e., annual fecal-occult blood testing [FOBT] and/or periodic flexible sigmoidoscopy for persons aged > or =50 years) to reduce colorectal cancer-related mortality. In 1997, the American Cancer Society and an interdisciplinary task force developed guidelines that recommend one test or a combination of several tests for colorectal cancer screening. To estimate the proportion of the U.S. population that received colorectal cancer screening tests, CDC analyzed data from the 1997 Behavioral Risk Factor Surveillance System (BRFSS) on the use of a home-administered blood stool test, or FOBT, and sigmoidoscopy/proctoscopy. This report summarizes the results of this analysis, which documents low rates of use of colorectal cancer screening tests. (+info)
Potential explanations for the educational gradient in coronary heart disease: a population-based case-control study of Swedish women.
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OBJECTIVES: This study examined the association between educational attainment and coronary heart disease (CHD) and the factors that may explain this association. METHODS: This population-based case-control study included 292 women with CHD who were 65 years or younger and 292 age-matched controls. RESULTS: Compared with the adjusted odds ratio for CHD associated with college education, the age-adjusted odds ratio associated with mandatory education (< or = 9 years) was 1.87 (95% confidence interval [CI] = 1.23, 2.84) and the odds ratio for high school education was 1.35 (95% CI = 0.81, 2.25) (P for trend < .01). The odds ratio for mandatory education was reduced by 82%, to 1.16 (95% CI = 0.69, 2.09), after adjustment for psychosocial stress, unhealthy lifestyle patterns, hemostatic factors, hypertension, and lipids. CONCLUSIONS: Much of the increased risk of CHD in women with low education appears to be linked to psychosocial stress and lifestyle factors. Hemostatic factors, lipids, and hypertension also contribute to a lesser extent. These factors may be considered in strategies geared to reducing socioeconomic inequalities in cardiovascular health. (+info)
Efficacy of Haemophilus influenzae type b conjugate vaccines and persistence of disease in disadvantaged populations. The Haemophilus Influenzae Study Group.
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OBJECTIVES: The purpose of this study was to evaluate the effectiveness of Haemophilus influenzae type b (Hib) conjugate vaccines among children aged 2 to 18 months and to determine risk factors for invasive Hib disease during a period of declining incidence (1991-1994). METHODS: A prospective population-based case-control study was conducted in a multistate US population of 15.5 million. A laboratory-based active surveillance system was used for case detection. RESULTS: In a multivariate analysis, having a single-parent mother (odds ratio [OR] = 4.3, 95% confidence interval [CI] = 1.2, 14.8) and household crowding (OR = 3.5, 95% CI = 1.03, 11.7) were risk factors for Hib disease independent of vaccination status. After adjustment for these risk factors, the protective efficacy of 2 or more Hib vaccine doses was 86% (95% CI = 16%, 98%). Among undervaccinated subjects, living with a smoker (P = .02) and several indicators of lower socioeconomic status were risk factors for Hib disease. CONCLUSIONS: Hib disease still occurs at low levels in the United States, predominantly in socioeconomically disadvantaged populations. Low immunization coverage may facilitate continuing transmission of Hib. Special efforts to achieve complete and timely immunization in disadvantaged populations are needed. (+info)
What's driving an epidemic? The spread of syphilis along an interstate highway in rural North Carolina.
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OBJECTIVES: The purpose of this study was to determine whether county syphilis rates were increased along Interstate Highway 95 (I-95) in North Carolina during a recent epidemic. METHODS: Ecological data on syphilis cases demographic data, highway data, and drug activity data were used to conduct a cross-sectional and longitudinal study of North Carolina countries from 1985 to 1994. Crude and adjusted incidence rate ratios (IRRs) were determined by means of standard and longitudinal Poisson regression models adjusted for sociodemographic factors and drug use. RESULTS: Ten-year syphilis rates in I-95 counties greatly exceeded rates in non-I-95 counties (38 vs 16 cases per 100,000 persons) and remained higher after adjustment for race, age, sex, poverty, large cities, and drug activity (adjusted IRR = 2.05, 95% confidence interval [CI] = 1.84, 2.28). Syphilis rates were stable until 1989, when rates increased sharply in I-95 counties but remained stable in non-I-95 counties. Increased drug activity in I-95 counties preceded the rise in syphilis cases. CONCLUSIONS: A better understanding of the relationship between high-ways and the spread of sexually transmitted diseases may guide future prevention interventions. (+info)
A deviation bar chart for detecting dengue outbreaks in Puerto Rico.
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OBJECTIVES: A Centers for Disease Control and Prevention deviation bar chart (Statistical Software for Public Health Surveillance) and laboratory-based surveillance data were evaluated for their utility in detecting dengue outbreaks in Puerto Rico. METHODS: A significant increase in dengue incidence was defined as an excess of suspected cases of more than 2 SDs beyond the mean for all 4-week periods from April through June (the period of lowest seasonal incidence), 1989 through 1993. An outbreak was defined as a cumulative annual rate of reported dengue greater than 3 per 1000 population. RESULTS: Retrospective application of the system to 1994 data showed agreement with previous analyses. In 1995 and 1996, 36.4% and 27.3%, respectively, of municipalities with a significant increase in reports for 2 or more consecutive weeks before the first week of September had an outbreak, compared with 9.0% (in 1995, P = .042) and 6.0% (in 1996, P = .054) of towns without a significant increase. The system showed sensitivity near 40%, specificity near 89%, and accuracy in classifying municipalities near 84%. CONCLUSIONS: This method provides a statistically based, visually striking, specific, and timely signal for dengue control efforts. (+info)
The new old epidemic of coronary heart disease.
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OBJECTIVES: This study quantified the consequences for prevalence of increased survival of coronary heart disease (CHD) in the Netherlands from 1980 to 1993. METHODS: A multistage life table fitted observed mortality and registration rates from the nationwide hospital register. The outcome was prevalence by age, sex, period, and disease state. RESULTS: The prevalence of CHD from 1980 to 1993 was 4.4% (men, aged 25 to 84 years) and 1.4% (women, aged 25 to 84 years). Between 1980-1983 and 1990-1993, the incidence changed little, but age-adjusted prevalence increased by 19% (men) and 59% (women). CONCLUSIONS: Sharply decreasing mortality but near-constant attack rates of CHD caused distinct increases in prevalence, particularly among the elderly. (+info)