BACKGROUND: Little is known as to whether medical home principles, such as continuity of care (COC), would have the same effect on health service use for individuals whose primary (or predominant) provider is a specialist instead of a primary care provider (PCP). OBJECTIVE: To test associations between health service use and expenditures and (1) beneficiaries' predominant provider type (PCP or specialist) and (2) COC among beneficiaries who primarily see a PCP and those who primarily see a specialist. RESEARCH DESIGN: This is a cross-sectional analysis of Medicare fee-for-service claims data from July 2007 to June 2009. Negative binomial and generalized linear models were used in multivariate regression modeling. SUBJECTS: The study cohort comprised 613,471 community-residing Medicare fee-for-service beneficiaries. MEASURES: Beneficiaries' predominant provider type and COC index during a baseline period (July 2007-June 2008) were studied. All-cause and ambulatory care sensitive condition (ACSC) hospitalizations and emergency department (ED) visits and related expenditures and total expenditures in a 1-year follow-up period (July 2008-June 2009) were also reported. RESULTS: Twenty-five percent of beneficiaries primarily saw a specialist. Having a specialist predominant provider was associated with 9% fewer ED visits, 14% fewer ACSC ED visits, and 8% fewer ACSC hospitalizations (all P<0.001). Regardless of whether the beneficiary's predominant provider was a specialist or a PCP, higher continuity was associated with fewer all-cause hospitalizations and ED visits and lower expenditures for these services. Higher continuity was also associated with lower total expenditures. CONCLUSIONS: Regardless of the predominant provider's specialty, greater continuity was associated with less use of high-cost services and lower expenditures for these services
