Food Some cultures consume blood, sometimes in the form of blood sausage, as a thickener for sauces, or in a cured, salted form for times of food scarcity, and others use blood in stews such as jugged hare. Some cultures and people do not consume meat or animal food products for cultural, dietary, health, ethical, or ideological reasons. Vegetarians choose to forgo food from animal sources to varying degrees. Vegans do not consume any foods that are or contain ingredients from an animal source. Adulteration is a legal term meaning that a food product fails to meet the legal standards. One
Time-varying covariate Time-varying covariate A time-varying covariate (also called time-dependent covariate) is a term used in statistics, particularly in survival analyses. It reflects the phenomenon that a covariate is not necessarily constant through the whole study. For instance, if one wishes to examine the link between area of residence and cancer, this would be complicated by the fact that study subjects move from one area to another. The area of residency could then be introduced in the statistical model as a time-varying covariate. In survival analysis, this would be done by splitting each study subject into several observations, one for each area