title: Subspecialty care use rates: reverse causation and generalizability issues.
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Mayer
mesh_terms: D006279:Health Maintenance Organizations / Q000706:statistics & numerical data; D006801:Humans; D008329:Managed Care Programs / Q000706:statistics & numerical data; D008511:Medicine; D019095:Point-of-Care Systems / Q000706:statistics & numerical data; D012017:Referral and Consultation / Q000706:statistics & numerical data; D013038:Specialization; D006113:United Kingdom; D014481:United States