Background and aims: Multiple sclerosis (MS) is an inflammatory disease of the central nervous system.The impact of the number of attacks on the disease is undeniable. The aim of this study was to analyze thenumber of attacks in these patients.Methods: In this descriptive-analytical study, the registered data of 1840 MS patients referred to the MS clinicof Ayatollah Kash...

Abstract Smallholder farmers’ preferences for participation in contract farming may take the form of proportional data––whereby farmers only sell some proportions or fractions their output to contractors. We analyze determinants zero (potential corner solution) and amounts milk that through farming, using dairy data from Zambia. Bayesian linear, linear probability, hurdle models are compared wi...

INTRODUCTION Count data are often collected in chronic disease research, and sometimes these data have a skewed distribution. The number of unhealthy days reported in the Behavioral Risk Factor Surveillance System (BRFSS) is an example of such data: most respondents report zero days. Studies have either categorized the Healthy Days measure or used linear regression models. We used alternative r...

This paper describes a compound Poisson-based random effects structure for modeling zero-inflated data. Data with large proportion of zeros are found in many fields of applied statistics, for example in ecology when trying to model and predict species counts (discrete data) or abundance distributions (continuous data). Standard methods for modeling such data include mixture and two-part conditi...