Wartime determinants of arteriographically confirmed coronary artery disease in Beirut

This study investigates the association of wartime stress variables and coronary artery disease as determined by coronary angiography in Lebanon in 1986, a country with an ongoing civil war for over a decade. A total of 127 patients who underwent coronary angiography at the American University of Beirut Medical Center were individually matched on age and sex with visitor controls free from any evidence of clinical coronary artery disease. Arteriographic cases (greater than or equal to 70% maximal stenosis) were compared with two control groups: arteriographic controls (entirely normal coronaries) and visitor controls. Findings suggest that there is a relation between exposure to both acute and chronic war events and coronary artery disease in this patient population. The reporting of exposure to acute war events was significantly higher in cases compared with both visitor controls (odds ratio (OR) = 2.4, 95% confidence interval (Cl) 1.17-4.90) and arteriographic controls (OR = 2.8, 95% Cl 0.93-8.47). Crossing the "green-lines" that separate two belligerent sides, considered as an attribute of war-related chronic stress, was more frequent in cases compared with visitor controls (OR = 3.25, 95% Cl 1.54-6.89) and arteriographic controls (OR = 5.38, 95% Cl 1.65-17.6). The relation observed between wartime stress and coronary artery disease could not be explained by possible overreporting of stressful events in patients with suspected coronary artery disease or by an increase in clinical awareness for the disease for those under continuous stress. Adjusting for the effect of the well-established coronary artery disease risk factors did not alter the above findings.     

Wartime determinants of arteriographically confirmed coronary artery disease in Beirut

This study investigates the association of wartime stress variables and coronary artery disease as determined by coronary angiography in Lebanon in 1986, a country with an ongoing civil war for ever a decade. A total of 127 patients who underwent coronary angiography at the American University of Beirut Medical Center were individually matched on age and sex with visitor controls free from any evidence of clinical coronary artery disease. Arteriographic cases (greater than or equal to 70% maximal stenosis) were compared with two control groups: arteriographic controls (entirely normal coronaries) and visitor controls. Findings suggest that there is a relation between exposure to both acute and chronic war events and coronary artery disease in this patient population. The reporting of exposure to acute war events was significantly higher in cases compared with both visitor controls (odds ratio (OR) = 2.4, 95% confidence interval (CI) 1.17-4.90) and arteriographic controls (OR = 2.8, 95% CI 0.93-8.47). Crossing the "green-lines" that separate two belligerent sides, considered as an attribute of war-related chronic stress, was more frequent in cases compared with visitor controls (OR = 3.25, 95% CI 1.54-6.89) and arteriographic controls (OR = 5.38, 95% CI 1.65-17.6). The relation observed between wartime stress and coronary artery disease could not be explained by possible overreporting of stressful events in patients with suspected coronary artery disease or by an increase in clinical awareness for the disease for those under continuous stress. Adjusting for the effect of the well-established coronary artery disease risk factors did not alter the above findings.     

Health behaviors and cancer screening practices in long-term survivors of hematopoietic cell transplantation (HCT): a report from the BMT Survivor Study

Patients undergoing hematopoietic cell transplantation (HCT) are at increased risk of chronic health conditions, including second malignant neoplasms and cardiovascular disease. Little is known about health behaviors and cancer screening practices among HCT survivors that could moderate the risk of these conditions. The BM transplant survivor study examined health behaviors and cancer screening practices in individuals who underwent HCT between 1976 and 1998, and survived 2+ years. Health behavior was deemed as high risk, if an individual was a current smoker and if they reported risky alcohol intake (≥4 drinks per day (males), ≥3 drinks per day (females)) on days of alcohol consumption. Cancer screening assessment was per American Cancer Society recommendations. There were 1040 survivors: 42.7% underwent allogeneic HCT; 43.8% were female; median time from HCT: 7.4 years (range 2.0-27.7 years). Median age at study participation: 43.8 years (range 18.3-73.0 years). Multivariate regression analysis revealed younger age (<35 years) at study participation (Odds ratio (OR)=4.7; P<0.01) and lower education (相似文献   

A positive or a negative confounding variable? A simple teaching aid for clinicians and students

Anticipating the direction of a confounding variable can be problematic especially to introductory students. Using elementary rules of mathematics, we describe below a simple instructional tool for deriving the direction of confounding bias. The tool is illustrated with examples and a heuristic mathematical justification is also described.     

Application of case-crossover and case-time-control study designs in analyses of time-varying predictors of T-cell homeostasis failure

PURPOSE: To evaluate the association of sexual behavior and recreational drug exposures with T-cell homeostasis failure (TCHF), which corresponds to the onset of a rapid decline in an individual's T lymphocyte count, which occurs on average approximately 1.75 years prior to an initial diagnosis of acquired immunodeficiency syndrome (AIDS). METHODS: A case-crossover design and a case-time-control design, both nested within the Multicenter AIDS Cohort Study of 4954 homosexual and bisexual men initiated in 1983. RESULTS: In the case-crossover analysis, use of both recreational drugs and hashish were found to be protective against TCHF (odds ratios < or = 0.41), based on comparisons with four earlier control periods. However, a significant decreasing trend in the prevalence of these exposures was observed over time, thus motivating the implementation of the case-time-control design. Using the latter approach, the associations of drug use (odds ratio=0.53; 95% confidence interval (CI): 0.22, 1.28) and hashish use (odds ratio=0.46; 95% CI: 0.20, 1.05) with TCHF were no longer statistically significant. CONCLUSIONS: The difference in inferences between these approaches demonstrates the importance of evaluating temporal trends in exposures when using a case-crossover design.     

Predictors of discharges against medical advice from a short-term hospital detoxification unit.

The primary goal of this study was to identify factors associated with patients leaving a 3-day hospital detoxification unit against medical advice (AMA). Medical records of 302 patients who were admitted for alcohol or other drug withdrawal were reviewed. Variables examined were: demographics, reported history of drug use, urine toxicology at admission, medication received during the detoxification, and admission day. Data were analyzed using a case-control design. Logistic regression was used to identify independent predictors. We found that being younger, having a shorter history of cocaine abuse, being admitted on a Friday and being an opiate dependent patient treated with clonidine only during the detoxification, were significantly associated with leaving AMA. These findings may provide information that can help clinicians identify those patients who are most at risk for leaving AMA. This will in turn allow them the opportunity to initiate preventive measures to decrease unnecessary attrition and improve utilisation of treatment resources.     

Elevated HPRT mutation frequencies in aflatoxin-exposed residents of daxin, Qidong county, People's Republic of China.

Molecular biomarkers are becoming increasingly important tools to identify people who are at highest risk of developing cancer. For many years we have been studying residents of Qidong County, People's Republic of China, to examine the combined impact of aflatoxin exposure with other risk factors as contributors to the high liver cancer incidence rates in this region. This study was conducted to determine the effects of aflatoxin exposure, as measured by serum aflatoxin-albumin adduct levels, on somatic mutation frequency in the human hypoxanthine guanine phosphoribosyl transferase gene (HPRT). Subjects were assigned as low or high according to a dichotomization around the population mean of aflatoxin-albumin adducts. HPRT mutant frequency was determined in individuals by a T cell clonal assay and the samples were categorized as low or high according to mean values. Separate analyses were also conducted for the small set of hepatitis B virus surface antigen (HBsAg)-positive and the larger set of HBsAg-negative individuals, known risk factors for liver cancer. An odds ratio of 19.3 (95% confidence interval 2.0, 183) was demonstrated for a high HPRT mutation frequency in individuals with high aflatoxin exposure compared with those with low aflatoxin exposure. This association indicates that aflatoxin-induced DNA damage in T lymphocytes, assessed using the validated surrogate albumin adduct markers, leads to increased mutations reflected as elevated HPRT gene mutations. This cross-sectional study suggests the potential use of mutation frequency of the HPRT gene as a long-term biomarker of aflatoxin exposure in high risk populations.