Physician- versus practice-level primary care continuity and association with outcomes in Medicare beneficiaries

Abstract

Objective: To compare physician-level versus practice-level primary care continuity and their association with expenditure and acute care utilization among Medicare beneficiaries and evaluate whether continuity of outpatient primary care at either/both physician or/and practice level could be useful quality measures.

Data source: Medicare Fee-For-Service claims data for community dwelling beneficiaries without end-stage renal disease who were attributed to a national random sample of primary care practices billing Medicare (2011-2017).

Study design: Retrospective secondary data analysis at per Medicare beneficiary per year level. We used multivariable linear regression with practice-level fixed effects to estimate continuity of care score at physician versus practice level and their associations with outcomes.

Data collection/extraction method: We calculated clinician- and practice-level Bice-Boxerman continuity of care index scores, ranging from 0 to 1, using primary care outpatient claims. Medicare expenditures, hospital admissions, emergency department (ED) visits, and readmissions were obtained from the Medicare Beneficiary Summary File: Cost and Utilization Segment. Ambulatory care sensitive conditions (ACSC) were defined using diagnosis codes on inpatient claims.

Principal findings: We studied 2,359,400 beneficiaries who sought care from 13,926 physicians. Every 0.1 increase in physician continuity score was associated with a $151 reduction in expenditure per beneficiary per year (p < 0.01), and every 0.1 increase in practice continuity score was associated with $282 decrease (p < 0.01) per beneficiary per year. Both physician- and practice-level continuity were associated with lower Medicare expenditures among small, medium, and large practices. Both physician- and practice-level continuity were associated with lower probabilities of hospitalization, ED visit, admissions for ACSC, and readmission.

Conclusions: Primary care continuity of care could serve as a potent value-based care quality metric. Physician-level continuity is a unique value center that cannot be supplanted by practice-level continuity.

Keywords: continuity of care; population health; primary care; value-based payment.