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Specialty Use Among Patients With Treated Hypertension in a Patient-Centered Medical Home

A Capsule Commentary to this article was published on 20 March 2014



Little is known about how delivery of primary care in the patient-centered medical home (PCMH) influences outpatient specialty care use.


To describe changes in outpatient specialty use among patients with treated hypertension during and after PCMH practice transformation.


One-group, 48-month interrupted time series across baseline, PCMH implementation and post-implementation periods.


Adults aged 18–85 years with treated hypertension.


System-wide PCMH redesign implemented across 26 clinics in an integrated health care delivery system, beginning in January 2009.


Resource Utilization Band variables from the Adjusted Clinical Groups case mix software characterized overall morbidity burden (low, medium, high). Negative binomial regression models described adjusted annual differences in total specialty care visits. Poisson regression models described adjusted annual differences in any use (yes/no) of selected medical and surgical specialties.


Compared to baseline, the study population averaged 7 % fewer adjusted specialty visits during implementation (P < 0.001) and 4 % fewer adjusted specialty visits in the first post-implementation year (P = 0.02). Patients were 12 % less likely to have any cardiology visits during implementation and 13 % less likely during the first post-implementation year (P < 0.001). In interaction analysis, patients with low morbidity had at least 27 % fewer specialty visits during each of 3 years following baseline (P < 0.001); medium morbidity patients had 9 % fewer specialty visits during implementation (P < 0.001) and 5 % fewer specialty visits during the first post-implementation year (P = 0.007); high morbidity patients had 3 % (P = 0.05) and 5 % (P = 0.009) higher specialty use during the first and second post-implementation years, respectively.


Results suggest that more comprehensive primary care in this PCMH redesign enabled primary care teams to deliver more hypertension care, and that many needs of low morbidity patients were within the scope of primary care practice. New approaches to care coordination between primary care teams and specialists should prioritize high morbidity, clinically complex patients.

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  1. 1.

    American Academy of Family Physicians, American Academy of Pediatrics, American College of Physicians, American Osteopathic Association. Joint principles of the patient-centered medical home. 2007; Accessed January 10, 2014.

  2. 2.

    Berenson RA, Hammons T, Gans DN, et al. A house is not a home: keeping patients at the center of practice redesign. Health Aff (Millwood). 2008;27(5):1219–1230.

    PubMed  Article  Google Scholar 

  3. 3.

    Peikes D, Zutshi A, Genevro JL, Parchman ML, Meyers DS. Early evaluations of the medical home: building on a promising start. Am J Manag Care. 2012;18(2):105–116.

    PubMed  Google Scholar 

  4. 4.

    Williams JW, Jackson GL, Powers BJ, et al. The Patient-Centered Medical Home. Closing the Quality Gap: Revisiting the State of the Science. Agency for Healthcare Research and Quality: Rockville, MD; 2012.

    Google Scholar 

  5. 5.

    Jackson GL, Powers BJ, Chatterjee R, et al. The Patient-Centered Medical Home: A Systematic Review. Ann Int Med. 2013;158(3):169–178.

    Article  Google Scholar 

  6. 6.

    Rittenhouse DR, Thom DH, Schmittdiel JA. Developing a policy-relevant research agenda for the patient-centered medical home: a focus on outcomes. J Gen Intern Med. 2010;25(6):593–600.

    PubMed Central  PubMed  Article  Google Scholar 

  7. 7.

    Rosenthal MB, Beckman HB, Forrest DD, Huang ES, Landon BE, Lewis S. Will the patient-centered medical home improve efficiency and reduce costs of care? A measurement and research agenda. Med Care Res Rev. 2010;67(4):476–484.

    PubMed  Article  Google Scholar 

  8. 8.

    Hollingsworth JM, Saint S, Hayward RA, Rogers MA, Zhang L, Miller DC. Specialty care and the patient-centered medical home. Med Care. 2011;49(1):4–9.

    PubMed  Article  Google Scholar 

  9. 9.

    Reid RJ, Fishman PA, Yu O, et al. Patient-centered medical home demonstration: a prospective, quasi-experimental, before and after evaluation. Am J Manag Care. 2009;15(9):e71–e87.

    PubMed  Google Scholar 

  10. 10.

    American College of Physicians. The Patient-Centered Medical Home Neighbor: The Interface of the Patient-Centered Medical Home with Specialty/Subspecialty Practices. 2010; Accessed January 10, 2014.

  11. 11.

    Fisher ES. Building a medical neighborhood for the medical home. N Engl J Med. 2008;359(12):1202–1205.

    CAS  PubMed Central  PubMed  Article  Google Scholar 

  12. 12.

    Starfield B. Point: the changing nature of disease: implications for health services. Med Care. 2011;49(11):971–972.

    PubMed  Article  Google Scholar 

  13. 13.

    Forrest CB, Reid RJ. Prevalence of health problems and primary care physicians’ specialty referral decisions. J Fam Pract. 2001;50(5):427–432.

    CAS  PubMed  Google Scholar 

  14. 14.

    Forrest CB. A typology of specialists’ clinical roles. Arch Intern Med. 2009;169(11):1062–1068.

    PubMed  Article  Google Scholar 

  15. 15.

    Starfield B, Lemke KW, Bernhardt T, Foldes SS, Forrest CB, Weiner JP. Comorbidity: implications for the importance of primary care in ‘case’ management. Ann Fam Med. 2003;1(1):8–14.

    PubMed Central  PubMed  Article  Google Scholar 

  16. 16.

    Starfield B, Lemke KW, Herbert R, Pavlovich WD, Anderson G. Comorbidity and the use of primary care and specialist care in the elderly. Ann Fam Med. 2005;3(3):215–222.

    PubMed Central  PubMed  Article  Google Scholar 

  17. 17.

    Roos NP, Carriere KC, Friesen D. Factors influencing the frequency of visits by hypertensive patients to primary care physicians in Winnipeg. CMAJ. 1998;159(7):777–783.

    CAS  PubMed Central  PubMed  Google Scholar 

  18. 18.

    Margolius D, Bodenheimer T. Controlling hypertension requires a new primary care model. Am J Manag Care. 2010;16(9):648–650.

    PubMed  Google Scholar 

  19. 19.

    Reid RJ, Johnson EA, Hsu C, et al. Spreading a medical home redesign: effects on emergency department use and hospital admissions. Ann Fam Med. 2013;11(Suppl 1):S19–S26.

    PubMed Central  PubMed  Article  Google Scholar 

  20. 20.

    Hsu C, Coleman K, Ross TR, et al. Spreading a patient-centered medical home redesign: a case study. J Ambul Care Manag. 2012;35(2):99–108.

    Article  Google Scholar 

  21. 21.

    Reid RJ, Coleman K, Johnson EA, et al. The group health medical home at year two: cost savings, higher patient satisfaction, and less burnout for providers. Health Aff (Millwood). 2010;29(5):835–843.

    PubMed  Article  Google Scholar 

  22. 22.

    Liss DT, Fishman PA, Rutter CM, et al. Outcomes among chronically ill adults in a medical home prototype. Am J Manag Care. 2013;19(10):e348–e358.

    PubMed  Google Scholar 

  23. 23.

    Shadish WR, Cook TD, Campbell DT. Experimental and Quasi-Experimental Designs for Generalized Causal Inference. Boston: Houghton Mifflin; 2002.

    Google Scholar 

  24. 24.

    Bullano MF, Kamat S, Willey VJ, Barlas S, Watson DJ, Brenneman SK. Agreement between administrative claims and the medical record in identifying patients with a diagnosis of hypertension. Med Care. 2006;44(5):486–490.

    PubMed  Article  Google Scholar 

  25. 25.

    Sibai BM. Diagnosis and management of chronic hypertension in pregnancy. Obstet Gynecol. 1991;78(3 Pt 1):451–461.

    CAS  PubMed  Google Scholar 

  26. 26.

    Carrell D, Ralston J. Messages, strands and threads: measuring use of electronic patient-provider messaging. AMIA Annu Symp Proc. 2005:913.

  27. 27.

    Hardcastle JD, Chamberlain JO, Robinson MH, et al. Randomised controlled trial of faecal-occult-blood screening for colorectal cancer. Lancet. 1996;348(9040):1472–1477.

    CAS  PubMed  Article  Google Scholar 

  28. 28.

    The Johns Hopkins ACG System: Technical Reference Guide, Version 10.0. Baltimore, MD: Johns Hopkins University; 2011.

  29. 29.

    Forrest CB, Nutting PA, Starfield B, von Schrader S. Family physicians’ referral decisions: results from the ASPN referral study. J Fam Pract. 2002;51(3):215–222.

    PubMed  Google Scholar 

  30. 30.

    Ralston JD, Martin DP, Anderson ML, et al. Group health cooperative’s transformation toward patient-centered access. Med Care Res Rev. 2009;66(6):703–724.

    PubMed  Article  Google Scholar 

  31. 31.

    Gardner W, Mulvey EP, Shaw EC. Regression analyses of counts and rates: Poisson, overdispersed Poisson, and negative binomial models. Psychol Bull. 1995;118(3):392–404.

    CAS  PubMed  Article  Google Scholar 

  32. 32.

    Zou G. A modified poisson regression approach to prospective studies with binary data. Am J Epidemiol. 2004;159(7):702–706.

    PubMed  Article  Google Scholar 

  33. 33.

    Zou GY, Donner A. Extension of the modified Poisson regression model to prospective studies with correlated binary data. Stat Methods Med Res. 2011.

  34. 34.

    Diggle P, Heagerty P, Liang K, Zeger S. Analysis of Longitudinal Data. 2nd ed. Norfolk, UK: Oxford University Press; 2002.

    Google Scholar 

  35. 35.

    Rockford Register Star. Key dates of the Great Recession. 2012; Accessed January 10, 2014.

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We thank all members of the study team, including Kelly Ehrlich, MS (project management) and Eric Johnson, MS (analytic support). Clarissa Hsu, PhD, DeAnn Cromp, MPH and Katie Coleman, MSPH supported planning and reviewed early manuscript drafts. We also thank Claire Trescott, MD and Michael Erikson, MSW for their leadership during Group Health’s medical home redesign, and Karen Severson, RN for sharing information about hypertension care protocols at Group Health.

Funding was provided by the National Center for Advancing Translational Sciences (#TL1 RR025016), the Agency for Healthcare Research and Quality (#R18 HS019129) and Group Health Cooperative.

Conflict of Interest

Dr. Fishman, Dr. Rutter and Mr. Ross are employees of Group Health Cooperative, and Dr. Liss is a former employee of Group Health Cooperative. Dr. Reid is an employee and shareholder of Group Health Physicians, the medical group affiliated with Group Health Cooperative.

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Correspondence to David T. Liss PhD.

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Liss, D.T., Fishman, P.A., Rutter, C.M. et al. Specialty Use Among Patients With Treated Hypertension in a Patient-Centered Medical Home. J GEN INTERN MED 29, 732–740 (2014).

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  • primary care redesign
  • patient centered care
  • health care delivery
  • specialty care
  • hypertension