A new parametric model for the econometric analysis of non-negative integers is proposed. Its distinguishing feature is that it allows for more flexible variance-mean relationships than the models used hitherto. Estimation with maximum likelihood is illustrated using a dataset on ship damage incidents. A New Approach for Modeling Economic Count Data Forthcoming: Economics Letters Rainer Winkelm...

BACKGROUND Although non-normal data are widespread in biomedical research, parametric tests unnecessarily predominate in statistical analyses. METHODS We surveyed five biomedical journals and - for all studies which contain at least the unpaired t-test or the non-parametric Wilcoxon-Mann-Whitney test - investigated the relationship between the choice of a statistical test and other variables ...

Parametric methods are commonly used despite evidence that model assumptions are often violated. Various statistical procedures have been suggested for analyzing data from multiple-group repeated measures (i.e., split-plot) designs when parametric model assumptions are violated (e.g., Akritas and Arnold (J. Amer. Statist. Assoc. 89 (1994) 336); Brunner and Langer (Biometrical J. 42 (2000) 663))...

Using two sets of data, including daily prices (open, close, high and low) of all S&P 500 stocks between 1992 and 1996, we perform a satistical test of the predictive capability of candlestick patterns. Out-of-sample tests indicate statistical signiŽcance at the level of 36 standard deviations from the null hypothesis, and indicate a proŽt of almost 1% during a two-day holding period. An essent...

The cytological dilemma of distinguishing malignant cells from proliferating mesothelium has generated volumes of research but no clear consensus regarding an optimal staining panel. nm23 has been frequently described in malignant cells as a metastasis suppressor, but its mechanism of action and the relationship between nm23 expression, metastases, and prognosis is controversial. This is the fi...

The application of ergonomics in product design is essential to its accessibility and usability. The development of manual devices should be based on ergonomic principles. Effort perception analysis is an essential approach to understand the physical and subjective aspects of the interface. The objective of the present study was to analyze the effort perception during a simulated task with diff...

BACKGROUND To establish whether a previously validated scoring system (Habib) for the prediction of risk or likelihood of posterior capsule rupture during phacoemulsification surgery could be used to: 1. Predict the difficulty of a phacoemulsification case, and 2. Select appropriate phacoemulsification cases for trainees. METHODS The study sample was consecutive phacoemulsification cases unde...

The Audit Commission in the UK recommends that patient information leaflets (PILs) should be audited by health professionals using a formal readability test. However, no such study on antiepileptic drugs (AEDs) has been identified in a Medline search. The aim of this study was to audit the readability of PILs prepared for marketed proprietary AEDs in the UK. Twelve PILs were compared with six a...

When you are assessing the quality of the evidence, it’s not how the data are analyzed that’s important. Far more important is how the data are collected. Don’t agonize over whether the researchers should have used a non-parametric test or whether a random effects meta-analysis is appropriate (just to cite two obscure examples). These are important issues and they generate a lot of debate. But ...

BACKGROUND There are inconsistent reports about multiple sclerosis (MS) risk among migrants from low to high MS risk geographical regions. This study assessed the overall MS incidence and evaluated seasonality in birth and subsequent MS risk later in the life in second generation of migrants born and lived in Kuwait. METHODS We assessed the overall and gender-specific MS risk in second genera...