Estimating Age-specific Prevalence of Testosterone Deficiency in Men Using Normal Mixture Models

Testosterone levels decline as men age.There is little consensus on what testosterone levels are normal for aging men.In this paper, we estimate age-specific prevalence of testosterone deficiency in men using normal mixture models when no generally agreed on cut-off value for defining testosterone deficiency is available.The Box-Cox power transformation is used to determine which transformation is most appropriate for correcting skewness in data and best suits normal mixture distributions.Parametric bootstrap tests are used to determine the number of components in a normal mixture.