A compound attribute that is the ratio of amount of collagen alpha-1(I) chain (human) in blood to amount of osteomodulin (human) in blood. The trait is COL1A1/OMD protein level ratio in blood (OBA_2053870, an Ontology of Biological Attributes term). Also known as: the ratio of amount of collagen alpha-1(I) chain (human) in blood to amount of osteomodulin (human) in blood.