995 resultados para Logistic rationalization
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The human leukocyte antigen (HLA) DRB1*1501 has been consistently associated with multiple sclerosis (MS) in nearly all populations tested. This points to a specific antigen presentation as the pathogenic mechanism though this does not fully explain the disease association. The identification of expression quantitative trait loci (eQTL) for genes in the HLA locus poses the question of the role of gene expression in MS susceptibility. We analyzed the eQTLs in the HLA region with respect to MS-associated HLA-variants obtained from genome-wide association studies (GWAS). We found that the Tag of DRB1*1501, rs3135388 A allele, correlated with high expression of DRB1, DRB5 and DQB1 genes in a Caucasian population. In quantitative terms, the MS-risk AA genotype carriers of rs3135388 were associated with 15.7-, 5.2- and 8.3-fold higher expression of DQB1, DRB5 and DRB1, respectively, than the non-risk GG carriers. The haplotype analysis of expression-associated variants in a Spanish MS cohort revealed that high expression of DRB1 and DQB1 alone did not contribute to the disease. However, in Caucasian, Asian and African American populations, the DRB1*1501 allele was always highly expressed. In other immune related diseases such as type 1 diabetes, inflammatory bowel disease, ulcerative colitis, asthma and IgA deficiency, the best GWAS-associated HLA SNPs were also eQTLs for different HLA Class II genes. Our data suggest that the DR/DQ expression levels, together with specific structural properties of alleles, seem to be the causal effect in MS and in other immunopathologies rather than specific antigen presentation alone.
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Intravenous drug injection has been reported as the main risk factor for hepatitis C virus (HCV) infection. The aim of the present study was to describe the prevalence and the epidemiological profile of HCV infection among abusers of illegal injected and non-injected drugs in Cuiabá, state of Mato Grosso, Central Brazil. A cross-sectional study including 314 male drug users from eight detoxification centres was performed. Out of 314 subjects studied, 48 (15.2%) were intravenous drug users. Participants were interviewed and had blood samples taken and tested for the presence of anti-HCV antibodies. Positive samples were tested for the presence of HCV RNA. Genotyping was performed on HCV RNA-positive samples. The overall prevalence of anti-HCV antibodies was 6.4% (n = 20). Out of 20 anti-HCV antibody-positive subjects, 16 (80%) were also HCV RNA-positive. Genotype 1 predominated (75%), followed by 3a (25%). Subtype 1a was more common than 1b. HCV infection was more prevalent among intravenous drug users (33%) than non-injecting users (1.5%). Logistic regression analyses showed independent associations between HCV infection and intravenous drug use, imprisonment and increasing age. In the present study, injecting drug use was the factor most strongly associated to HCV infection and inhaling or sniffing did not represent an increased susceptibility to infection.
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There is little literature about the clinical presentation and time-course of postoperative venous thromboembolism (VTE) in different surgical procedures. RIETE is an ongoing, prospective registry of consecutive patients with objectively confirmed, symptomatic acute VTE. In this analysis, we analysed the baseline characteristics, thromboprophylaxis and therapeutic patterns, time-course, and three-month outcome of all patients with postoperative VTE. As of January 2006, there were 1,602 patients with postoperative VTE in RIETE: 393 (25%) after major orthopaedic surgery (145 elective hip arthroplasty, 126 knee arthroplasty, 122 hip fracture); 207 (13%) after cancer surgery; 1,002 (63%) after other procedures. The percentage of patients presenting with clinically overt pulmonary embolism (PE) (48%, 48%, and 50% respectively), the average time elapsed from surgery to VTE (22 +/- 16, 24 +/- 16, and 21 +/- 15 days, respectively), and the three-month incidence of fatal PE (1.3%, 1.4%, and 0.8%, respectively), fatal bleeding (0.8%, 1.0%, and 0.2%, respectively), or major bleeding (2.3%, 2.9%, and 2.8%, respectively) were similar in the three groups. However, the percentage of patients who had received thromboprophylaxis (96%, 76% and 52%, respectively), the duration of prophylaxis (17 +/- 9.6, 13 +/- 8.9, and 12 +/- 11 days, respectively) and the mean daily doses of low-molecular-weight heparin (4,252 +/- 1,016, 3,260 +/- 1,141, and 3,769 +/- 1,650 IU, respectively), were significantly lower in those undergoing cancer surgery or other procedures. In conclusion, the clinical presentation, time-course, and three-month outcome of VTE was similar among the different subgroups of patients, but the use of prophylaxis in patients undergoing cancer surgery or other procedures was suboptimal.
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BACKGROUND Available screening tests for dementia are of limited usefulness because they are influenced by the patient's culture and educational level. The Eurotest, an instrument based on the knowledge and handling of money, was designed to overcome these limitations. The objective of this study was to evaluate the diagnostic accuracy of the Eurotest in identifying dementia in customary clinical practice. METHODS A cross-sectional, multi-center, naturalistic phase II study was conducted. The Eurotest was administered to consecutive patients, older than 60 years, in general neurology clinics. The patients' condition was classified as dementia or no dementia according to DSM-IV diagnostic criteria. We calculated sensitivity (Sn), specificity (Sp) and area under the ROC curves (aROC) with 95% confidence intervals. The influence of social and educational factors on scores was evaluated with multiple linear regression analysis, and the influence of these factors on diagnostic accuracy was evaluated with logistic regression. RESULTS Sixteen neurologists recruited a total of 516 participants: 101 with dementia, 380 without dementia, and 35 who were excluded. Of the 481 participants who took the Eurotest, 38.7% were totally or functionally illiterate and 45.5% had received no formal education. Mean time needed to administer the test was 8.2+/-2.0 minutes. The best cut-off point was 20/21, with Sn = 0.91 (0.84-0.96), Sp = 0.82 (0.77-0.85), and aROC = 0.93 (0.91-0.95). Neither the scores on the Eurotest nor its diagnostic accuracy were influenced by social or educational factors. CONCLUSION This naturalistic and pragmatic study shows that the Eurotest is a rapid, simple and useful screening instrument, which is free from educational influences, and has appropriate internal and external validity.
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The perspectives for a Chagas Disease vaccine 30 years ago and today are compared. Antigens and adjuvants have improved, but logistic problems remain the same. Sterilizing vaccines have not been produced and animal models for chronic Chagas have not been developed. Vector control has been successful and Chagas incidence has come to a halt. We do not have a population candidate to vaccination now in Brazil. And if we had, we would not know how to evaluate the success of vaccination in a short time period. A vaccine may not seem important at the moment. However, scientific reasons and incertitudes about the future recommend that a search for a vaccine be continued.
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Aitchison and Bacon-Shone (1999) considered convex linear combinations ofcompositions. In other words, they investigated compositions of compositions, wherethe mixing composition follows a logistic Normal distribution (or a perturbationprocess) and the compositions being mixed follow a logistic Normal distribution. Inthis paper, I investigate the extension to situations where the mixing compositionvaries with a number of dimensions. Examples would be where the mixingproportions vary with time or distance or a combination of the two. Practicalsituations include a river where the mixing proportions vary along the river, or acrossa lake and possibly with a time trend. This is illustrated with a dataset similar to thatused in the Aitchison and Bacon-Shone paper, which looked at how pollution in aloch depended on the pollution in the three rivers that feed the loch. Here, I explicitlymodel the variation in the linear combination across the loch, assuming that the meanof the logistic Normal distribution depends on the river flows and relative distancefrom the source origins
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BACKGROUND: Chronic kidney disease (CKD) represents an increasing health burden. We present the population-based prevalence of CKD and compare the CKD Epidemiology collaboration (CKD-EPI) and modification of diet in renal disease (MDRD) equations to estimate the glomerular filtration rate, using the revised CKD classification with three albuminuria classes. We also explore factors associated with CKD. METHODS: The Swiss population-based, cross-sectional CoLaus study conducted in Lausanne (2003-2006) included 2810 men and 3111 women aged 35-75. CKD prevalence was assessed using CKD-EPI and MDRD equations and albuminuria estimated by the albumin-to-creatinine ratio in spot morning urine. Multivariate logistic regression was used to analyse determinants of CKD. RESULTS: Prevalence [95% confidence interval (CI)] of all stages CKD was 10.0% (9.2-10.8%) with CKD-EPI and 13.8% (12.9-14.6%) with MDRD. Using the revised CKD classification, the prevalence of low-, medium-, high- and very high-risk groups was 90.0, 8.46, 1.18 and 0.35% with CKD-EPI, respectively. With MDRD, the corresponding values were 86.24, 11.86, 1.55 and 0.35%. Using the revised classification, CKD-EPI systematically reclassified people in a lower risk category than MDRD. Age and obesity were more strongly associated with CKD in men [odds ratio (95% CI): 2.23(1.95; 2.56) per 10 years and 3.05(2.08;4.47), respectively] than in women [1.46 (1.29; 1.65) and 1.78 (1.30;2.44), respectively]. Hypertension, type 2 diabetes, serum homocysteine and uric acid were positively independently associated with CKD in men and women. CONCLUSIONS: One in 10 adults suffers from CKD in the population of Lausanne. CKD-EPI systematically reclassifies people in a lower CKD risk category than MDRD. Serum homocysteine and uric acid levels are associated with CKD independently of classical risk factors such as age, hypertension and diabetes.
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BACKGROUND: Surveillance is an essential element of surgical site infection (SSI) prevention. Few studies have evaluated the long-term effect of these programmes. AIM: To present data from a 13-year multicentre SSI surveillance programme from western and southern Switzerland. METHODS: Surveillance with post-discharge follow-up was performed according to the US National Nosocomial Infections Surveillance (NNIS) system methods. SSI rates were calculated for each surveyed type of surgery, overall and by year of participation in the programme. Risk factors for SSI and the effect of surveillance time on SSI rates were analysed by multiple logistic regression. FINDINGS: Overall SSI rates were 18.2% after 7411 colectomies, 6.4% after 6383 appendicectomies, 2.3% after 7411 cholecystectomies, 1.7% after 9933 herniorrhaphies, 1.6% after 6341 hip arthroplasties, and 1.3% after 3667 knee arthroplasties. The frequency of SSI detected after discharge varied between 21% for colectomy and 94% for knee arthroplasty. Independent risk factors for SSI differed between operations. The NNIS risk index was predictive of SSI in gastrointestinal surgery only. Laparoscopic technique was protective overall, but associated with higher rates of organ-space infections after appendicectomy. The duration of participation in the surveillance programme was not associated with a decreased SSI rate for any of the included procedure. CONCLUSION: These data confirm the effect of post-discharge surveillance on SSI rates and the protective effect of laparoscopy. There is a need to establish alternative case-mix adjustment methods. In contrast to other European programmes, no positive impact of surveillance duration on SSI rates was observed.
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BACKGROUND Increasing trend and geographical variations in the use of caesarean section suggest the influence of non-clinical factors. The objective was to describe the use of caesarean section in the Andalusian region in Spain by exploring the role of social, clinical, and health services variables. METHODS A cross-sectional study was carried out using vital statistics. It involves all births occurred in Andalusia during the period of 2007-2009. The dependent variable was the use of caesarean section and the set of covariates were classified into three groups: those with a clinical meaning, those related to the health services organization, and those with a social significance. Multivariate logistic regressions were used. RESULTS In the data set of 293,558 births, the prevalence of caesarean delivery was 24.8%. The multivariate analysis highlights the labour complications as the clinical variable with the highest odds ratio (OR=19.36). Regarding the health services variables, the odds of experiencing a caesarean delivery were 55% higher on weekdays than on weekends. Cádiz was the province with the highest OR for caesarean section (comparison between Cádiz and Almería: OR=1,21) where the ratio between births in public and private hospitals was 3.7. The frequency of caesarean section was 34% higher in women with third level education than those with no education. CONCLUSIONS Labour complication is the most influential variable for caesarean section. Caesarean birth rate is above the accepted standards for all social classes and increases with educational level. Inter-provincial differences reflect different patterns with regard to the use of private medicine.
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PURPOSE. To evaluate potential risk factors for the development of multiple sclerosis in Brazilian patients. METHOD. A case control study was carried out in 81 patients enrolled at the Department of Neurology of the Hospital da Lagoa in Rio de Janeiro, and 81 paired controls. A standardized questionnaire on demographic, social and cultural variables, and medical and family history was used. Statistical analysis was performed using descriptive statistics and conditional logistic regression models with the SPSS for Windows software program. RESULTS. Having standard vaccinations (vaccinations specified by the Brazilian government) (OR=16.2; 95% CI=2.3-115.2), smoking (OR=7.6; 95% CI=2.1-28.2), being single (OR=4.7; 95% CI=1.4-15.6) and eating animal brain (OR=3.4; 95% CI=1.2-9.8) increased the risk of developing MS. CONCLUSIONS. RESULTS of this study may contribute towards better awareness of the epidemiological characteristics of Brazilian patients with multiple sclerosis.
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Pregnancy reduces maternal risk of breast cancer in the long term, but the biological determinants of the protection are unknown. Animal experiments suggest that estrogens and progesterone could be involved, but direct human evidence is scant. A case-control study (536 cases and 1,049 controls) was nested within the Finnish Maternity Cohort. Eligible were primiparous women who delivered at term a singleton offspring before age 40. For each case, two individually matched controls by age (±6 months) and date of sampling (±3 months) were selected. Estradiol, estrone and progesterone in first-trimester serum were measured by high-performance liquid chromatography tandem mass spectrometry and sex-hormone binding globulin (SHBG) by immunoassay. Odds ratios (OR) and 95% confidence intervals (CI) were estimated through conditional logistic regression. In the whole study population there was no association of breast cancer with any of the studied hormones. In analyses stratified by age at diagnosis, however, estradiol concentrations were positively associated with risk of breast cancer before age 40 (upper quartile OR, 1.81; CI, 1.08-3.06), but inversely associated with risk in women who were diagnosed ≥age 40 (upper quartile OR, 0.64; CI, 0.40-1.04), p(interaction) 0.004. Risk estimates for estrone mirrored those for estradiol but were less pronounced. Progesterone was not associated with risk of subsequent breast cancer. Our results provide initial evidence that concentrations of estrogens during the early parts of a primiparous pregnancy are associated with maternal risk of breast cancer and suggest that the effect may differ for tumors diagnosed before and after age 40.
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QUESTION UNDER STUDY: To assess how important the possibility to choose specialist physicians is for Swiss residents and to determine which variables are associated with this opinion. METHODS: This cross-sectional study used data from the 2007 Swiss population-based health survey and included 13,642 non-institutionalised adults who responded to the telephone and paper questionnaires. The dependent variable included answers to the question "How important is it for you to be able to choose the specialist you would like to visit?" Independent variables included socio-demographics, health and past year healthcare use measures. Crude and adjusted logistic regressions for the importance of being able to choose specialist physicians were performed, accounting for the survey design. RESULTS: 45% of participants found it very important to be able to choose the specialist physician they wanted to visit. The answers "rather important", "rather not important" and "not important" were reported by 28%, 20% and 7% of respondents. Women, individuals in middle/high executive position, those with an ordinary insurance scheme, those reporting ≥2 chronic conditions or poorer subjective health, or those who had had ≥2 outpatient visits in the preceding year were more likely to find this choice very important. CONCLUSIONS: In 2007, almost half of all Swiss residents found it very important to be able to choose his/her specialist physician. The further development of physician networks or other chronic disease management initiatives in Switzerland, towards integrated care, need to pay attention to the freedom of choice of specialist physicians that Swiss residents value. Future surveys should provide information on access and consultations with specialist physicians.
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INTRODUCTION Refractory septic shock has dismal prognosis despite aggressive therapy. The purpose of the present study is to report the effects of terlipressin (TP) as a rescue treatment in children with catecholamine refractory hypotensive septic shock. METHODS We prospectively registered the children with severe septic shock and hypotension resistant to standard intensive care, including a high dose of catecholamines, who received compassionate therapy with TP in nine pediatric intensive care units in Spain, over a 12-month period. The TP dose was 0.02 mg/kg every four hours. RESULTS Sixteen children (age range, 1 month-13 years) were included. The cause of sepsis was meningococcal in eight cases, Staphylococcus aureus in two cases, and unknown in six cases. At inclusion the median (range) Pediatric Logistic Organ Dysfunction score was 23.5 (12-52) and the median (range) Pediatric Risk of Mortality score was 24.5 (16-43). All children had been treated with a combination of at least two catecholamines at high dose rates. TP treatment induced a rapid and sustained improvement in the mean arterial blood pressure that allowed reduction of the catecholamine infusion rate after one hour in 14 out of 16 patients. The mean (range) arterial blood pressure 30 minutes after TP administration increased from 50.5 (37-93) to 77 (42-100) mmHg (P < 0.05). The noradrenaline infusion rate 24 hours after TP treatment decreased from 2 (1-4) to 1 (0-2.5) microg/kg/min (P < 0.05). Seven patients survived to the sepsis episode. The causes of death were refractory shock in three cases, withdrawal of therapy in two cases, refractory arrhythmia in three cases, and multiorgan failure in one case. Four of the survivors had sequelae: major amputations (lower limbs and hands) in one case, minor amputations (finger) in two cases, and minor neurological deficit in one case. CONCLUSION TP is an effective vasopressor agent that could be an alternative or complementary therapy in children with refractory vasodilatory septic shock. The addition of TP to high doses of catecholamines, however, can induce excessive vasoconstriction. Additional studies are needed to define the safety profile and the clinical effectiveness of TP in children with septic shock.
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OBJECTIVES To assess the relationship between life styles and eating habits with the overweight and obesity prevalence in a Spanish adult population. METHODS A population-based, cross-sectional study conducted on 2640 subjects older than 15 years, in Cádiz (Spain). Surveys were conducted in subjects' homes to obtain life styles, eating habits, and anthropometric data. Logistic regression has been used to study the association between the life style variables and overweight and obesity. RESULTS Prevalence of overweight and obesity in Cadiz is 37% and 17%, respectively; higher in males and increases with age. BMI has an inverse relationship with educational level (PR = 2.3, 1.57-2.38). The highest levels of obesity are associated with daily alcohol consumption (PR = 1.39, 1.29-1.50), greater consumption of television,and sedentary pursuit (PR 1.5, 1.07-1.24). A lower prevalence of obesity is observed among those with active physical activity (10.9% vs 21.6%), with differences between sex. Following a slimming diet is more frequent in the obese and in women but dedicate more hours than men to passive activities. In men is greater the consumption of alcohol, high energy foods and snacks. Overweight and obesity is associated with the male sex (OR = 3.35 2.75-4.07), high consumption of alcohol (OR = 1.38 1.03-1.86) and watching television (OR = 1.52 1.11-2.07), and foods likes bread and cereals (OR = 1.47 1.13-1.91). Exercise activities is a protective factor (OR = 0.76 0.63-0.98). CONCLUSIONS Life styles factors associated with overweight and obesity present different patterns in men and women and is necessary to understand them to identify areas for behavioural intervention in overweight and obesity patients.
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BACKGROUND Evidence associating exposure to water disinfection by-products with reduced birth weight and altered duration of gestation remains inconclusive. OBJECTIVE We assessed exposure to trihalomethanes (THMs) during pregnancy through different water uses and evaluated the association with birth weight, small for gestational age (SGA), low birth weight (LBW), and preterm delivery. METHODS Mother-child cohorts set up in five Spanish areas during the years 2000-2008 contributed data on water ingestion, showering, bathing, and swimming in pools. We ascertained residential THM levels during pregnancy periods through ad hoc sampling campaigns (828 measurements) and regulatory data (264 measurements), which were modeled and combined with personal water use and uptake factors to estimate personal uptake. We defined outcomes following standard definitions and included 2,158 newborns in the analysis. RESULTS Median residential THM ranged from 5.9 μg/L (Valencia) to 114.7 μg/L (Sabadell), and speciation differed across areas. We estimated that 89% of residential chloroform and 96% of brominated THM uptakes were from showering/bathing. The estimated change of birth weight for a 10% increase in residential uptake was -0.45 g (95% confidence interval: -1.36, 0.45 g) for chloroform and 0.16 g (-1.38, 1.70 g) for brominated THMs. Overall, THMs were not associated with SGA, LBW, or preterm delivery. CONCLUSIONS Despite the high THM levels in some areas and the extensive exposure assessment, results suggest that residential THM exposure during pregnancy driven by inhalation and dermal contact routes is not associated with birth weight, SGA, LBW, or preterm delivery in Spain.