Adolescent, Adult, Aged, Aged, 80 and over, Algorithms, Anticoagulants, Aryl Hydrocarbon Hydroxylases, Child, Cohort Studies, Cytochrome P-450 CYP2C9, Dose-Response Relationship, Drug, Female, Genotype, Humans, International Normalized Ratio, Least-Squares Analysis, Male, Middle Aged, Mixed Function Oxygenases, Pharmacogenetics, Polymorphism, Single Nucleotide, Vitamin K Epoxide Reductases, Warfarin, Young Adult