Score tests for zero-inflated Poisson models

N Jansakul, JP Hinde - Computational statistics & data analysis, 2002 - Elsevier
In many situations count data have a large proportion of zeros and the zero-inflated Poisson
regression (ZIP) model may be appropriate. A simple score test for zero-inflation, comparing …

Analysis of zero‐inflated Poisson data incorporating extent of exposure

AH Lee, K Wang, KKW Yau - Biometrical Journal, 2001 - Wiley Online Library
When analyzing Poisson count data sometimes a high frequency of extra zeros is observed.
The Zero‐Inflated Poisson (ZIP) model is a popular approach to handle zero‐inflation. In this …

A score test for testing a zero‐inflated Poisson regression model against zero‐inflated negative binomial alternatives

M Ridout, J Hinde, CGB Demétrio - Biometrics, 2001 - Wiley Online Library
Count data often show a higher incidence of zero counts than would be expected if the data
were Poisson distributed. Zero‐inflated Poisson regression models are a useful class of …

Zero‐inflated Poisson and binomial regression with random effects: a case study

DB Hall - Biometrics, 2000 - Wiley Online Library
In a 1992 Technometrics paper, Lambert (1992, 34, 1–14) described zero‐inflated Poisson
(ZIP) regression, a class of models for count data with excess zeros. In a ZIP model, a count …

Score test for zero inflated generalized Poisson regression model

PL Gupta, RC Gupta, RC Tripathi - Communications in Statistics …, 2005 - Taylor & Francis
In certain applications involving count data, it is sometimes found that zeros are observed
with a frequency significantly higher (lower) than predicted by the assumed model …

On estimation of the Poisson parameter in zero-modified Poisson models

E Dietz, D Böhning - Computational Statistics & Data Analysis, 2000 - Elsevier
For count data, typically, a Poisson model is assumed. However, it has been observed in
various applications that this model does not fit, because of too few or too many zeros in the …

Multi-level zero-inflated Poisson regression modelling of correlated count data with excess zeros

AH Lee, K Wang, JA Scott, KKW Yau… - Statistical methods in …, 2006 - journals.sagepub.com
Count data with excess zeros relative to a Poisson distribution are common in many
biomedical applications. A popular approach to the analysis of such data is to use a zero …

A score test for zero inflation in a Poisson distribution

J Van den Broek - Biometrics, 1995 - JSTOR
A Score Test for Zero Inflation in a Poisson Distribution Page 1 BIOMETRICS 51, 738-743 June
1995 A Score Test for Zero Inflation in a Poisson Distribution Jan van den Broek Center for …

Modeling health survey data with excessive zero and K responses

TH Lin, MH Tsai - Statistics in Medicine, 2013 - Wiley Online Library
Zero‐inflated Poisson regression is a popular tool used to analyze data with excessive
zeros. Although much work has already been performed to fit zero‐inflated data, most …

Score tests for zero-inflation in overdispersed count data

Z Yang, JW Hardin, CL Addy - Communications in Statistics …, 2010 - Taylor & Francis
The negative binomial (NB) model and the generalized Poisson (GP) model are common
alternatives to Poisson models when overdispersion is present in the data. Having …