The global effects of digestive system cancers worldwide on the COVID-19 pandemic by negative binomial (mixed) regression models

Abstract

In this study, the main goal is to determine statistically significant relationships between the biggest epidemic problem of last years as the COVID-19 pandemic and digestive system cancers belonging to 168 countries worldwide using generalized linear mixed model (GLMM) and its special case as generalized linear model (GLM) approaches, and to obtain global inferences that will shed light on this pandemic. For this goal, the response variable is “total cases of the COVID-19 pandemic per 100,000 people” until January 14, 2022. The explanatory variables are total number of people suffering from colon and rectum, stomach, lip and oral cavity, esophageal, and nasopharynx cancers belonging to 2019, respectively. In this study, the negative binomial (NB) regression model in GLM using iteratively reweighted least squares (IRLS) algorithm and the NB mixed regression model in GLMM with “countries” taken as “random effects” using Adaptive Gauss-Hermite Quadrature (AGHQ) approximation method at 1, 2, 10, and 20 quadrature points are used for modelling the COVID-19 pandemic and digestive systems cancer data. In this study, by using information criteria, the NB mixed regression model in GLMM under log-link function with 168 countries taken as random effects using AGHQ method at 20 quadrature point is detected as the most appropriate model for the global COVID-19 pandemic and digestive system cancers data.