title: Measuring change in primary care.
mesh_terms: D003258:Consumer Behavior; D003266:Continuity of Patient Care; D006302:Health Services Research; D006801:Humans; D010818:Practice Patterns, Physicians' / Q000639:trends; D011320:Primary Health Care / Q000458:organization & administration*; D012017:Referral and Consultation; D014481:United States