João Gomes

In-hospital mortality in spontaneous bacterial peritonitis: a new predictive model.

Introduction and objective Spontaneous bacterial peritonitis (SBP) is a severe complication in cirrhotics with ascites. Early identification of high-risk patients is crucial for prognostic improvement. Model for end-stage liver disease (MELD) relies on a few objective variables and predicts short-term survival. We aimed to determine the predictive value of MELD score, at admission, in the short-term mortality of SBP patients. Methods We conducted a retrospective study of 73 SBP episodes admitted in our department between January 2002 and April 2006. Diagnosis (neutrophil count in ascitic fluid ≥250/mm3) was established within 24 h and cefotaxime was immediately started. Data collected included age, sex, etiology of liver disease, severity of ascites and hepatic encephalopathy, serum creatinine, total bilirubin and albumin, prothrombin time with international normalized ratio, and ascitic fluid analysis. Statistics Students t-test, χ2 test, univariate analysis, logistic regression model, and receiver operating characteristic curves. Results In-hospital mortality rate was 37%. In multivariate analysis, MELD score (P<0.001), and advanced age (P<0.05) were independent predictors of mortality. Receiver operating characteristic curve for MELD score revealed an excellent discriminatory ability to predict death, with an area under curve of 0.84. Age increased the predictive ability of MELD score, represented by an increment of area under curve to 0.88. Conclusion MELD score and older age were independent predictors of mortality. Age increased the discriminatory ability of MELD score to predict death. This new model may be useful for stratifying patients in future therapeutic trials, deserving further validation.

Diphtheria, pertussis, and measles in Portugal before and after mass vaccination : A time series analysis

Techniques of time series analysis were used to examine historical records of the incidence of diphtheria, pertussis, and measles, and of deaths by measles in Portugal during the twentieth century. There are statistically significant seasonal and long-term oscillations in the incidence of these diseases. Seasonal oscillations appear to be in close association with the resumption of school classes in the fall in the case of diphtheria, but not in pertussis and measles. Long-term oscillations in pertussis (3.5–4 year period) and measles (3-year period), before vaccination, corroborate theoretical predictions about the dynamics of these diseases, whereas absence of long-term oscillations in diphtheria is probably due to the influential presence of carriers upon the dynamics of the disease. Mass vaccination strongly suppressed disease incidence, did not eliminate seasonal oscillations, and appeared to have acted to lengthen long-term periodicity in pertussis and measles.

Factores associados à hipertensão arterial nos utentes de farmácias em Portugal

OBJETIVO: Estimar a prevalencia, tratamento e controlo da hipertensao e identificar factores associados em utentes de farmacias comunitarias. METODOS: Estudo transversal com 1.042 utentes de 40 a 65 anos em 60 farmacias comunitarias de Portugal Continental entre outubro de 2005 e janeiro de 2006. Os dados foram obtidos pela aplicacao de questionario e medicao de parâmetros biologicos. Foram realizadas tres regressoes logisticas sequenciais para verificar associacao entre as variaveis. RESULTADOS: A idade media foi de 53,7 anos e a razao homem/mulher foi 0,68. A prevalencia da hipertensao arterial foi de 54,8%. Cerca de 70% dos hipertensos encontravam-se sob tratamento anti-hipertensivo e, destes, 47,7% estavam controlados. A hipertensao esteve positivamente associada a idade mais elevada, sexo masculino, ser casado, apresentar indice de massa corporal e nivel de colesterol total mais alto, ser diabetico, ter doenca cardiovascular pessoal ou familiar precoce e reportar mais consultas medicas por ano. A hipertensao tratada mostrou-se positivamente associada a ser mulher, nao casado, ser diabetico, viver numa area urbana e reportar mais de tres consultas medicas por ano. Nos hipertensos tratados, estar controlado foi positivamente associado a ter comportamento aderente a terapeutica anti-hipertensiva (auto-reporte), percepcionar o efeito desta medicacao e ser de baixo risco cardiovascular. Os modelos preditivos apresentaram areas sob as respectivas curvas ROC entre 0,72 e 0,78, com capacidade discriminatoria aceitavel. CONCLUSOES: A prevalencia da hipertensao foi elevada, mas similar a encontrada em outros estudos realizados em Portugal. A proporcao de doentes tratados foi satisfatoria, em contraste com o nivel insuficiente de controlo.OBJECTIVE To estimate the prevalence, treatment and control of hypertension, and to identify factors associated in community pharmacy users. METHODS A cross-sectional study was conducted with 1,042 pharmacy users, aged between 40 and 65 years, in 60 community pharmacies of continental Portugal, between October 2005 and January 2006. Data were obtained with the application of a questionnaire and measurement of biological parameters. A total of three sequential logistic regressions were performed to verify an association among variables. RESULTS Mean age was 53.7 years and the male/female ratio was 0.68. Prevalence of arterial hypertension was 54.8%. Approximately 70% of hypertensive individuals were undergoing antihypertensive treatment and, of these, 47.7% were controlled. Hypertension was positively associated with older age, male sex, being married, higher body mass index and higher total cholesterol level, being a diabetic, having a family or personal history of premature cardiovascular disease, and reporting more medical visits per year. When treated, hypertension was found to be positively associated with the female sex, not being married, being a diabetic, living in an urban area, and reporting more than three medical visits per year. In hypertensive users who were treated, being controlled was positively associated with self-reporting adherent behavior towards antihypertensive treatment, perceiving the effect of these drugs and having a low cardiovascular risk. The predictive models showed areas under the respective ROC curves between 0.72 and 0.78, with an acceptable discriminatory power. CONCLUSIONS The prevalence of hypertension was high, although similar to that found in other studies conducted in Portugal. The proportion of hypertensive individuals under treatment was satisfactory, in contrast to an insufficient level of control.

Factors associated with arterial hypertension in pharmacy users in Portugal

OBJETIVO: Estimar a prevalencia, tratamento e controlo da hipertensao e identificar factores associados em utentes de farmacias comunitarias. METODOS: Estudo transversal com 1.042 utentes de 40 a 65 anos em 60 farmacias comunitarias de Portugal Continental entre outubro de 2005 e janeiro de 2006. Os dados foram obtidos pela aplicacao de questionario e medicao de parâmetros biologicos. Foram realizadas tres regressoes logisticas sequenciais para verificar associacao entre as variaveis. RESULTADOS: A idade media foi de 53,7 anos e a razao homem/mulher foi 0,68. A prevalencia da hipertensao arterial foi de 54,8%. Cerca de 70% dos hipertensos encontravam-se sob tratamento anti-hipertensivo e, destes, 47,7% estavam controlados. A hipertensao esteve positivamente associada a idade mais elevada, sexo masculino, ser casado, apresentar indice de massa corporal e nivel de colesterol total mais alto, ser diabetico, ter doenca cardiovascular pessoal ou familiar precoce e reportar mais consultas medicas por ano. A hipertensao tratada mostrou-se positivamente associada a ser mulher, nao casado, ser diabetico, viver numa area urbana e reportar mais de tres consultas medicas por ano. Nos hipertensos tratados, estar controlado foi positivamente associado a ter comportamento aderente a terapeutica anti-hipertensiva (auto-reporte), percepcionar o efeito desta medicacao e ser de baixo risco cardiovascular. Os modelos preditivos apresentaram areas sob as respectivas curvas ROC entre 0,72 e 0,78, com capacidade discriminatoria aceitavel. CONCLUSOES: A prevalencia da hipertensao foi elevada, mas similar a encontrada em outros estudos realizados em Portugal. A proporcao de doentes tratados foi satisfatoria, em contraste com o nivel insuficiente de controlo.OBJECTIVE To estimate the prevalence, treatment and control of hypertension, and to identify factors associated in community pharmacy users. METHODS A cross-sectional study was conducted with 1,042 pharmacy users, aged between 40 and 65 years, in 60 community pharmacies of continental Portugal, between October 2005 and January 2006. Data were obtained with the application of a questionnaire and measurement of biological parameters. A total of three sequential logistic regressions were performed to verify an association among variables. RESULTS Mean age was 53.7 years and the male/female ratio was 0.68. Prevalence of arterial hypertension was 54.8%. Approximately 70% of hypertensive individuals were undergoing antihypertensive treatment and, of these, 47.7% were controlled. Hypertension was positively associated with older age, male sex, being married, higher body mass index and higher total cholesterol level, being a diabetic, having a family or personal history of premature cardiovascular disease, and reporting more medical visits per year. When treated, hypertension was found to be positively associated with the female sex, not being married, being a diabetic, living in an urban area, and reporting more than three medical visits per year. In hypertensive users who were treated, being controlled was positively associated with self-reporting adherent behavior towards antihypertensive treatment, perceiving the effect of these drugs and having a low cardiovascular risk. The predictive models showed areas under the respective ROC curves between 0.72 and 0.78, with an acceptable discriminatory power. CONCLUSIONS The prevalence of hypertension was high, although similar to that found in other studies conducted in Portugal. The proportion of hypertensive individuals under treatment was satisfactory, in contrast to an insufficient level of control.

Limit laws for a sequence between the maximum and the sum of independent exponentials

Consider a stochastic process {Xn}, n = 0, 1, 2, ... with initial value X0 and a sequence of independent, random variables, {Yi}, i [epsilon] N with exponential distribution with parameter one, where Xn+1 = max(Xn, [alpha]Xn + Yn+1), 0

Extreme value theory for a thermal energy storage model

A process to store solar energy to be used as thermal energy, with controlled input, may be represented by a stochastic process Xn, N = 0, 1, 2, ... with initial value Xo and a sequence of independent, identically distributed (i.i.d.) nonnegative random variables, Yi, i [epsilon] , where Xn + 1 = max([beta]Xn, [alpha][beta]Xn + Yn +1). 0 [less-than-or-equals, slant] [alpha]

Leverage web analytics for real time website browsing recommendations

As a websites’ structure grow it is paramount to accommodate the alignment of user needs and experience with the overall websites’ purposes. Toward this requirement, the proposed website navigation recommendation system suggests to users, pages that might be of her interest based on past successful navigation patterns of overall site’s usage. Most of existing recommendation systems adopts traditionally one of the web mining branches. We take a different stance, on web mining usage, and alternatively considered the real time enactment of web analytic tools supported analysis given their current maturity and affordances. On this basis we provide a model, its implementation and evaluation for navigation based recommendations generation and delivery. The developed prototype adopted a SaaS orientation to promote the underlying functionalities integration within any website. Preliminary evaluation’s results seem to favor the validation of the present contribution rational.

The Length of Hospital Stay in Acute Myocardial Infarction: A Predictive Model with Laboratory and Administrative Data

Introduction: The length of hospital stay (LOS) is an important measure of efficiency in the use of hospital resources. Acute Myocardial Infarction (AMI), as one of the diseases with higher mortality and LOS variability in the OECD countries, has been studied with predominant use of administrative data (AD). This paper presents preliminary results of a predictive model for LOS using both AD and laboratory data (LD) in order to develop a decision support system. Methods: LD and AD of a Portuguese hospital were included, using logistic regression to develop a predictive model for extended LOS. The examples of three individuals were performed to show how model works. Results: A model with three LD and seven AD variables, with excellent discriminative ability and a good calibration, was obtained. Age >= 69, presence of comorbidities and abnormal LD predict a higher probability of extended LOS.

Is It Always Necessary to Take Sample Selection into Account

We compare a simple ordinary least squares (OLS) with the maximum likelihood estimation of the Tobit I and Tobit II regression models, in the selected sample. We propose a new measure to quantify the performance of OLS.

Factores asociados con la hipertensión arterial en los usuarios de farmacias en Portugal

OBJETIVO: Estimar a prevalencia, tratamento e controlo da hipertensao e identificar factores associados em utentes de farmacias comunitarias. METODOS: Estudo transversal com 1.042 utentes de 40 a 65 anos em 60 farmacias comunitarias de Portugal Continental entre outubro de 2005 e janeiro de 2006. Os dados foram obtidos pela aplicacao de questionario e medicao de parâmetros biologicos. Foram realizadas tres regressoes logisticas sequenciais para verificar associacao entre as variaveis. RESULTADOS: A idade media foi de 53,7 anos e a razao homem/mulher foi 0,68. A prevalencia da hipertensao arterial foi de 54,8%. Cerca de 70% dos hipertensos encontravam-se sob tratamento anti-hipertensivo e, destes, 47,7% estavam controlados. A hipertensao esteve positivamente associada a idade mais elevada, sexo masculino, ser casado, apresentar indice de massa corporal e nivel de colesterol total mais alto, ser diabetico, ter doenca cardiovascular pessoal ou familiar precoce e reportar mais consultas medicas por ano. A hipertensao tratada mostrou-se positivamente associada a ser mulher, nao casado, ser diabetico, viver numa area urbana e reportar mais de tres consultas medicas por ano. Nos hipertensos tratados, estar controlado foi positivamente associado a ter comportamento aderente a terapeutica anti-hipertensiva (auto-reporte), percepcionar o efeito desta medicacao e ser de baixo risco cardiovascular. Os modelos preditivos apresentaram areas sob as respectivas curvas ROC entre 0,72 e 0,78, com capacidade discriminatoria aceitavel. CONCLUSOES: A prevalencia da hipertensao foi elevada, mas similar a encontrada em outros estudos realizados em Portugal. A proporcao de doentes tratados foi satisfatoria, em contraste com o nivel insuficiente de controlo.OBJECTIVE To estimate the prevalence, treatment and control of hypertension, and to identify factors associated in community pharmacy users. METHODS A cross-sectional study was conducted with 1,042 pharmacy users, aged between 40 and 65 years, in 60 community pharmacies of continental Portugal, between October 2005 and January 2006. Data were obtained with the application of a questionnaire and measurement of biological parameters. A total of three sequential logistic regressions were performed to verify an association among variables. RESULTS Mean age was 53.7 years and the male/female ratio was 0.68. Prevalence of arterial hypertension was 54.8%. Approximately 70% of hypertensive individuals were undergoing antihypertensive treatment and, of these, 47.7% were controlled. Hypertension was positively associated with older age, male sex, being married, higher body mass index and higher total cholesterol level, being a diabetic, having a family or personal history of premature cardiovascular disease, and reporting more medical visits per year. When treated, hypertension was found to be positively associated with the female sex, not being married, being a diabetic, living in an urban area, and reporting more than three medical visits per year. In hypertensive users who were treated, being controlled was positively associated with self-reporting adherent behavior towards antihypertensive treatment, perceiving the effect of these drugs and having a low cardiovascular risk. The predictive models showed areas under the respective ROC curves between 0.72 and 0.78, with an acceptable discriminatory power. CONCLUSIONS The prevalence of hypertension was high, although similar to that found in other studies conducted in Portugal. The proportion of hypertensive individuals under treatment was satisfactory, in contrast to an insufficient level of control.