Patients suffering from common illnesses seek assistance from their family physicians and are referred to tertiary care specialists only if unusual complications develop. Tertiary care specialists have performed the bulk of training and research for primary care physicians. The result is that research and education are inappropriate for the illnesses most often encountered in family practice. The Ambulatory Sentinel Practice Network (ASPN) was formed to gather information about the disorders encountered in general practice that form the greatest part of human suffering and to disseminate that information among primary care practitioners.