Gatekeeper products losing favor in many markets.
D019981:Health Care Sector / Q000639:trends; D006279:Health Maintenance Organizations / Q000191:economics / Q000458:organization & administration / Q000706:statistics & numerical data*; D006297:Health Services Accessibility / Q000458:organization & administration*; D011320:Primary Health Care / Q000191:economics / Q000458:organization & administration; D012017:Referral and Consultation; D020414:Risk Sharing, Financial; D014481:United States