A simulation study comparing aberration detection algorithms for syndromic surveillance

BACKGROUND: The usefulness of syndromic surveillance for early outbreak detection depends in part on effective statistical aberration detection. However, few published studies have compared different detection algorithms on identical data. In the largest simulation study conducted to date, we compared the performance of six aberration detection algorithms on simulated outbreaks superimposed on authentic syndromic surveillance data. METHODS: We compared three control-chart-based statistics, two exponential weighted moving averages, and a generalized linear model. We simulated 310 unique outbreak signals, and added these to actual daily counts of four syndromes monitored by Public Health – Seattle and King County's syndromic surveillance system. We compared the sensitivity of the six algorithms at detecting these simulated outbreaks at a fixed alert rate of 0.01. RESULTS: Stratified by baseline or by outbreak distribution, duration, or size, the generalized linear model was more sensitive than the other algorithms and detected 54% (95% CI = 52%–56%) of the simulated epidemics when run at an alert rate of 0.01. However, all of the algorithms had poor sensitivity, particularly for outbreaks that did not begin with a surge of cases. CONCLUSION: When tested on county-level data aggregated across age groups, these algorithms often did not perform well in detecting signals other than large, rapid increases in case counts relative to baseline levels

The prevalence of rheumatic diseases in central Greece: a population survey

<p>Abstract</p> <p>Background</p> <p>Rheumatic diseases are a major health and financial burden for societies. The prevalence of rheumatic diseases may change over time, and therefore, we sought to estimate the prevalence of rheumatic diseases in an adult population of central Greece.</p> <p>Methods</p> <p>In this prospective cross-sectional population survey, a random sample of adult population was drawn from poll catalogues of a region in central Greece. A postal questionnaire was sent to 3,528 people for the presence of any rheumatic disease. All positive cases were further confirmed by clinical examination using the American College of Rheumatoloy criteria. Multiple regression analysis was used to assess risk factors for rheumatic diseases.</p> <p>Results</p> <p>The response rate was 48.3% (1,705 answers). Four hundred and twenty individuals (24.6%) had a rheumatic disease. The prevalence of rheumatoid arthritis was 0.58% (95% confidence interval [CI], 0.32-0.87), of psoriatic arthritis was 0.35% (95% CI, 0.33-1.13), of ankylosing spondylitis was 0.29% (95% CI, 0.28-0.94), of primary Sjögren's syndrome was 0.23% (95% CI, 0.22-0.75) and of systemic lupus erythematosus was 0.11% (95% CI, 0.11-0.37). One individual had systemic sclerosis (prevalence, 0.058%), 1 individual had dermatomyositis (prevalence, 0.058%; 95% CI, 0.05-0.18), 2 individuals had vasculitis (prevalence 0.11%; 95% CI, 0.11-0.37), 81 individuals had gout (prevalence, 4.75%; 95% CI, 4.41-5.13), and 304 individuals had osteoarthritis (OA) (prevalence 17.82%; 95% CI, 16.50-19.34). Gout was associated with male gender, diabetes mellitus, and hypertension, and OA was associated with age, female gender, and hypertension.</p> <p>Conclusions</p> <p>Rheumatic diseases are common in central Greece, affecting nearly a quarter of adult population. OA and gout are the most common joint disorders.</p

Blood leptin and adiponectin as possible mediators of the relation between fat mass and BMD in perimenopausal women

Fat mass is a predictor of BMD; however, the mechanisms involved remain uncertain. Two adipokines, leptin and adiponectin, were examined as potential mediators of this relation in 80 perimenopausal women. Adiponectin did not exert any effect on BMD, whereas leptin exerted a negative one, with insulin acting as a confounder to this relation. Introduction: Fat mass is an important determinant of bone density, but the mechanism involved in this relation is uncertain. Leptin and adiponectin, as circulating peptides of adipocyte origin, are potential contributors to this relation. We investigated the role of leptin and adiponectin in mediating fat mass effects on the skeleton of perimenopausal women. Materials and Methods: Twenty-five premenopausal and 55 postmenopausal, healthy women (42-68 years old) participated in our study. Lumbar spine BMD (BMDL2-L4) and total body BMC (TBBMC) were measured with DXA, leptin levels with ELISA, and adiponectin levels with radioimmunoassay (RIA). Additionally, body composition analysis was performed, as well as measurements of several hormones. Results: It was shown that serum leptin levels were negatively correlated with BMD (beta = -0.005, p = 0.027) and TBBMC (beta = -14.32, p = 0.013). The above correlation was observed only when serum insulin levels were included, as an independent variable, in the regression analysis model. Adiponectin was not significantly correlated with BMDL2-L4 nor with TBBMC, either in the presence or absence of insulin. Conclusion: Circulating adiponectin does not seem to exert any effect on bone mass. In contrast, circulating leptin showed a negative correlation with bone mass, dependent on serum insulin levels

ACE/DD genotype is associated with hemostasis balance disturbances reflecting hypercoagulability and endothelial dysfunction in patients with untreated hypertension

Background Angiotensin-converting enzyme (ACE) gene polymorphism has been associated with an increased incidence of myocardial infarction. Recent studies have investigated a potential influence of ACE gene polymorphism on fibrinolysis or endothelial function. It has been previously established that essential hypertension is accompanied by endothelial dysfunction and fibrinolytic balance disorders. The aim of our study was to study the relation between ACE gene polymorphism and fibrinolytic/hemostatic factors as well as endothelial cell damage markers in patients with hypertension. Methods The following parameters were evaluated in 104 patients with previously untreated hypertension: plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator (IPA) antigen, fibrinogen, D-dimer, and von Willebrand factor (vWF). The genotype of the ACE gene was also determined (by the polymerase chain reaction method), and patients were characterized according to the observed alleles as deletion/deletion IDD), insertion/insertion till, or insertion/deletion (ID). Results Those with DD genotype tn = 42) had significantly higher plasma levels of PAI-I antigen (P = .012), IPA antigen (P = .0001), fibrinogen (P = .0002), D-dimer (P = .0001) and VWF (P = .0004) compared with ID (n = 30) or II (n = 32) genotypes. The ACE gene genotypes appeared to be significant predictors for plasma PAI-1 antigen, tPA antigen, fibrinogen, D-dimer, and VWF even after adjustment for age, sex, body mass index, triglyceride and cholesterol levels, and blood pressure. Conclusions Our findings suggest that the ACE/DD genotype is associated with hemostasis balance disturbances reflecting hypercoagulability and endothelial damage in patients with untreated hypertension