The aim of this Letter to the Editor was to report some methodological shortcomings in a recently published Article. We proved that the obtained results are subjected to the sparse data bias and presented some remedial tools such as penalization approaches. In addition, model fitting and performance aroused some controversies. In conclusion, the results of this study should be interpreted with caution and further reanalysis is necessary.
Keywords: Internal validity; Methodology; Prediction modelling; Predictive factors; Sparse data bias.