German cuisine widely available, but do not play an important role. Meat is usually braised; fried dishes also exist, but these recipes usually originate from France and Austria. Several cooking methods used to soften tough cuts have evolved into national specialties, including "Sauerbraten" (sour roast), involving marinating beef, horse meat or venison in a vinegar or wine vinegar mixture over several days. A long tradition of sausage-making exists in Germany; more than 1,500 different types of sausage () are made. Most "Wurst" is made with natural casings of pork, sheep or lamb intestines. Among the most popular and most common are "Bratwurst",
Time-varying covariate of residence. For example, if a person is born at time 0 in area A, moves to area B at time 5, and is diagnosed with cancer at time 8, two observations would be made. One with a length of 5 (5 − 0) in area A, and one with a length of 3 (8 − 5) in area B. 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