Summary
The R2 measure is a commonly used tool for assessing the predictive ability of a linear regression model. It quantifies the amount of variation in the outcome variable, which is explained by the covariates. Various attempts have been made to carry the R2 definition to other types of regression models as well. Here, two different R2 measure definitions for the Inverse Gaussian regression model will be studied. They are motivated by deviance and sums-of-squares residuals. Depending on sample size and number of covariates fitted, these R2 measures may show substantially inflated values, and a proper bias-adjustment is necessary. Several possible adjusted R2 measure definitions for the Inverse Gaussian regression model will be compared in a simulation study. The use of adjusted R2 measures is recommended in general.
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Acknowledgements
The authors thank Dr. T. Gruenberger, Department of Surgery, University of Vienna, for providing patients’ data. The authors also thank an anonymous associate editor and an anonymous referee for helpful suggestions which led to improvements in the manuscript.
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Heinzl, H., Mittlböck, M. Adjusted R2 Measures for the Inverse Gaussian Regression Model. Computational Statistics 17, 525–544 (2002). https://doi.org/10.1007/s001800200125
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DOI: https://doi.org/10.1007/s001800200125