Hospitals in Germany had traditionally provided care on a voluntary basis. Before the end of the nineteenth century, hospitalization was compulsory only during epidemics or in the case of infectious diseases such as syphilis or leprosy. Voluntary hospitalization normally occurred only when hospital beds were available, when payment was guaranteed, or during emergencies. Towards the end of the nineteenth century, however, there was a definite increase in hospitalization levels, primarily due to two important developments: the introduction of health insurance in 1883, and the growing number and size of hospitals. Health insurance covered its members' hospital expenses, and the hospitals provided facilities for more and more patients.