In this paper we suggest an extension of tile generalized power series distributions by including an additional parameter p. It has a natural interpretation in terms of both "zeroinflated" proportion and correlation coefficient. A new concept of p-type lack of memory property is introduced. The proposed new discrete distributions are candidates for modeling of correlated count data which exhibi...

We consolidate the zero-inflated Poisson model for count data with excess zeros (Lambert, 1992) and the two-component model approach for serial correlation among repeated observations (Dobbie and Welsh, 2001) for spatial count data. This concurrently addresses the problem of overdispersion and distinguishes zeros that arise due to random sampling from those that arise due to inherent characteri...

To investigate the quantitative distribution of Plasmodiumfalciparum gametocytes into the vector bloodmeal, Anopheles arabiensis mosquitoes were fed on 3 volunteers naturally infected with gametocytes. The content of each mosquito midgut was smeared on a microscope slide and Giemsa stained. The distribution of gametocytes ingested by mosquitoes followed a negative binomial distribution, with ap...

Poisson regression models provide a standard framework for the analysis of count data. In practice, however, count data are often overdispersed relative to the Poisson distribution. One frequent manifestation of overdispersion is that the incidence of zero counts is greater than expected for the Poisson distribution and this is of interest because zero counts frequently have special status. For...

OBJECTIVE To advance methods for the estimation of hospital performance based upon mortality ratios. DESIGN Observational study estimating trust performance in a year derived according to comparative standards from a 3-year period, accounting for patient-level case-mix and overdispersion (unexplained variability). PARTICIPANTS 23 363 630 admissions to the English National Health Service (NH...

The existing techniques of forecasting a future count either treat the time series of counts as a Gaussian time series or use a random effects based dynamic Poisson model. The normality based approach may not yield valid forecasting, whereas the random effects based model usually generates a complex correlation structure for the time series of counts which may be impractical to use for forecast...

OBJECTIVES To explore the history of symptomatic cystine stone formation. Cystinuria is a genetic defect that may result in the formation of recurrent cystine calculi. METHODS Thirty-four patients with cystinuria were retrospectively evaluated for treatment patterns, medical prophylaxis, and renal outcome. Patients were offered a conservative surgical regimen and routine radiographic and labo...