Primary care service areas: a new tool for the evaluation of primary care services.

OBJECTIVE To develop and characterize utilization-based service areas for the United States which reflect the travel of Medicare beneficiaries to primary care clinicians. DATA SOURCE/STUDY SETTING The 1996-1997 Part B and 1996 Outpatient File primary care claims for fee-for-service Medicare beneficiaries aged 65 and older. The 1995 Medicaid claims from six states (1995) and commercial claims from Blue Cross Blue Shield of Michigan (1996). STUDY DESIGN A patient origin study was conducted to assign 1999 U.S. zip codes to Primary Care Service Areas on the basis of the plurality of beneficiaries' preference for primary care clinicians. Adjustments were made to establish geographic contiguity and minimum population and service localization. Generality of areas to younger populations was tested with Medicaid and commercial claims. DATA COLLECTION/EXTRACTION METHODS Part B primary care claims were selected on the basis of provider specialty, place of service, and CPT code. Selection of Outpatient File claims used provider number, type of facility/service, and revenue center codes. PRINCIPAL FINDINGS The study delineated 6,102 Primary Care Service Areas with a median population of 17,276 (range 1,005-1,253,240). Overall, 63 percent of the Medicare beneficiaries sought the plurality of their primary care from within area clinicians. Service localization compared to Medicaid (six states) and commercial primary care utilization (Michigan) was comparable but not identical. CONCLUSIONS Primary Care Service Areas are a new tool for the measurement of primary care resources, utilization, and associated outcomes. Policymakers at all jurisdictional levels as well as researchers will have a standardized system of geographical units through which to assess access to, supply, use, organization, and financing of primary care services.

[1]  The Situation in Rural Districts as Regards Medical Services , 1928 .

[2]  A medical service area map of the United States; a progress report. , 1949, Journal of the American Medical Association.

[3]  A. Gittelsohn,et al.  Small Area Variations in Health Care Delivery , 1973, Science.

[4]  D. Makuc,et al.  Travel for Ambulatory Medical Care , 1983, Medical care.

[5]  D. Makuc,et al.  Service areas for ambulatory medical care. , 1985, Health services research.

[6]  J. Feldman,et al.  The use of health service areas for measuring provider availability. , 1991, The Journal of rural health : official journal of the American Rural Health Association and the National Rural Health Care Association.

[7]  F. Mullan,et al.  Primary care physician supply and the medically underserved. A status report and recommendations. , 1991, JAMA.

[8]  K. Davis.  Inequality and access to health care. , 1991, The Milbank quarterly.

[9]  The relationship between commuting patterns and health resources in nonmetropolitan counties of the United States. , 1992, Medical care.

[10]  B. Goody.  Defining rural hospital markets. , 1993, Health services research.

[11]  M Susser,et al.  The logic in ecological: I. The logic of analysis. , 1994, American journal of public health.

[12]  J. Rohrer,et al.  Geographic variation in primary care visits in Iowa. , 1995, Health services research.

[13]  K. Vranizan,et al.  Physician supply and access to care in urban communities. , 1997, Health affairs.

[14]  M. Whitcomb,et al.  The National Health Service Corps: Rural Physician Service and Retention , 1997, The Journal of the American Board of Family Medicine.

[15]  F. Mullan.  The National Health Service Corps and inner-city hospitals. , 1997, The New England journal of medicine.

[16]  What does Medicare pay for? Disentangling the flow of funds to health care providers. , 1998, Health affairs.

[17]  K. Hardwick,et al.  Eliminating primary care health professional shortage areas: the impact of Title VII generalist physician education. , 1999, The Journal of rural health : official journal of the American Rural Health Association and the National Rural Health Care Association.

[18]  E. Fisher,et al.  Capitation among Medicare beneficiaries. , 1999, Effective clinical practice : ECP.

[19]  M. Ward,et al.  Why rural residents migrate for family physician care. , 2000, The Journal of rural health : official journal of the American Rural Health Association and the National Rural Health Care Association.

[20]  Carlos Zarabozo,et al.  Milestones in Medicare Managed Care , 2000, Health care financing review.

[21]  G. Koch,et al.  State scholarship, loan forgiveness, and related programs: the unheralded safety net. , 2000, JAMA.

[22]  C. Forrest,et al.  Primary care safety-net delivery sites in the United States: A comparison of community health centers, hospital outpatient departments, and physicians' offices. , 2000, JAMA.

[23]  T. Ricketts,et al.  How many rural doctors do we have? , 2000, The Journal of rural health : official journal of the American Rural Health Association and the National Rural Health Care Association.

[24]  A. Monheit,et al.  The concentration of health care expenditures, revisited. , 2001, Health affairs.

[25]  L. Baker,et al.  Measuring competition in health care markets. , 2001, Health services research.

[26]  SECURITY MATTERS: HOW INSTABILITY IN HEALTH INSURANCE PUTS U.S. WORKERS AT RISK FINDINGS FROM THE COMMONWEALTH FUND 2001 HEALTH INSURANCE SURVEY , 2001 .

[27]  N. Paynter,et al.  Critical factors for designing programs to increase the supply and retention of rural primary care physicians. , 2001, JAMA.

[28]  J. Zwanziger,et al.  Use of Resident-Origin Data to Define Nursing Home Market Boundaries , 2002, Inquiry : a journal of medical care organization, provision and financing.