Inference in skew generalized t-link models for clustered binary outcome via a parameter-expanded EM algorithm

PLoS One. 2021 Apr 6;16(4):e0249604. doi: 10.1371/journal.pone.0249604. eCollection 2021.

Abstract

Binary Generalized Linear Mixed Model (GLMM) is the most common method used by researchers to analyze clustered binary data in biological and social sciences. The traditional approach to GLMMs causes substantial bias in estimates due to steady shape of logistic and normal distribution assumptions thereby resulting into wrong and misleading decisions. This study brings forward an approach governed by skew generalized t distributions that belong to a class of potentially skewed and heavy tailed distributions. Interestingly, both the traditional logistic and probit mixed models, as well as other available methods can be utilized within the skew generalized t-link model (SGTLM) frame. We have taken advantage of the Expectation-Maximization algorithm accelerated via parameter-expansion for model fitting. We evaluated the performance of this approach to GLMMs through a simulation experiment by varying sample size and data distribution. Our findings indicated that the proposed methodology outperforms competing approaches in estimating population parameters and predicting random effects, when the traditional link and normality assumptions are violated. In addition, empirical standard errors and information criteria proved useful for detecting spurious skewness and avoiding complex models for probit data. An application with respiratory infection data points out to the superiority of the SGTLM which turns to be the most adequate model. In future, studies should focus on integrating the demonstrated flexibility in other generalized linear mixed models to enhance robust modeling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Algorithms*
  • Bayes Theorem
  • Computer Simulation
  • Data Interpretation, Statistical*
  • Female
  • Humans
  • Linear Models
  • Male
  • Models, Statistical*
  • Research Design
  • Respiratory Tract Infections / drug therapy
  • Respiratory Tract Infections / pathology*

Grants and funding

CFT is grateful to the Centre d’Excellence Africain en Sciences Mathématiques et Applications (CEA-SMA, https://ceasma-benin.org/) for funding his work. CFT was also financially supported by the African German Network of Excellence in Science (AGNES), through the "AGNES mobility grant for young scientists from sub Saharan Africa" (https://agnes-h.org/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.