background : hepatitis b virus (hbv) is one of the most popular causes of chronic liver diseases through the world. there are approximately 350 million individuals infected with the hbv that 15 to 20 million of them are co-infected with hdv. it is known that co-existent infection with hdv tends to accelerate the progress of chronic hbv infection to chronic hepatitis, cirrhosis and hepatocellula...

Knee replacement (KR) is expensive and invasive. To date no predictive algorithms have been developed to identify individuals at high risk of surgery. This study assessed whether patient self-reported risk factors predict 10-year KR in a population-based study of 1,462 women aged over 70 years recruited for the Calcium Intake Fracture Outcome Study (CAIFOS). Complete hospital records of prevale...

The paper develops a new and easy-to-use F test in a time series GMM framework that allows for general forms of serial dependence. The test is based on the Wald statistic with a multiplicative correction factor and employs critical values from a standard F distribution. The F critical values are high-order correct under the conventional asymptotics. Monte Carlo simulations show that the F test ...

introduction: traffic accidents are the 8 th cause of mortality in different countries and are expected to rise to the 3 rd rank by 2020. based on the haddon matrix numerous factors such as environment, host, and agent can affect the severity of traffic-related traumas. therefore, the present study aimed to evaluate the effective factors in severity of these traumas based on haddon matrix. meth...

This paper presents an overview of some new results regarding an easily implementable Wald test-statistic (EFDF test) of the null hypotheses that a time-series process is I(1) or I(0) against fractional I(d) alternatives, with d ∈ (0, 1), allowing for unknown deterministic components and serial correlation in the error term. Specifically, we argue that the EFDF test has better power properties ...

Standard confidence intervals employed in applied statistical analysis are usually based on asymptotic approximations. Such approximations can be considerably inaccurate small and moderate sized samples. We derive accurate higher-order approximate quantiles of the score function. The coverage approximation error is O(n?3?2) while first-order distribution Wald, score, signed likelihood ratio sta...

An extension of the Rasch model with correlated latent variables is proposed to model correlated binary data within families. The latent variables have the classical correlation structure of Fisher (1918) and the model parameters thus have genetic interpretations. The proposed model is fitted to data using a hybrid of the Metropolis-Hastings algorithm and the MCEM modification of the EM-algorit...

BACKGROUND Reproductive factors provide an early window into a woman's coronary heart disease (CHD) risk; however, their contribution to CHD risk stratification is uncertain. METHODS AND RESULTS In the Women's Health Initiative Observational Study, we constructed Cox proportional hazards models for CHD including age, pregnancy status, number of live births, age at menarche, menstrual irregula...

This paper concerns the construction of confidence intervals in standard seroprevalence surveys. In particular, we discuss methods for constructing proportion individuals a population infected with disease using sample antibody test results and measurements test’s false positive negative rates. We begin by documenting erratic behavior coverage probabilities Wald percentile bootstrap when applie...

We propose a test for the order of integration of the univariate components of a vector process integrated of order two, i.e. an I(2) process, given by an autoregressive model. The null hypothesis of the test is that the particular univariate time series is an I(1) process. The hypotheses are formulated as linear restrictions on the directions orthogonal to the I(1) cointegration space. The sta...