Higher Primary Care Physician Continuity is Associated With Lower Costs and Hospitalizations

Abstract

Purpose: Continuity of care is a defining characteristic of primary care associated with lower costs and improved health equity and care quality. However, we lack provider-level measures of primary care continuity amenable to value-based payment, including the Medicare Quality Payment Program (QPP). We created 4 physician-level, claims-based continuity measures and tested their associations with health care expenditures and hospitalizations.

Methods: We used Medicare claims data for 1,448,952 beneficiaries obtaining care from a nationally representative sample of 6,551 primary care physicians to calculate continuity scores by 4 established methods. Patient-level continuity scores attributed to a single physician were averaged to create physician-level scores. We used beneficiary multilevel models, including beneficiary controls, physician characteristics, and practice rurality to estimate associations with total Medicare Part A & B expenditures (allowed charges, logged), and any hospitalization.

Results: Our continuity measures were highly correlated (correlation coefficients ranged from 0.86 to 0.99), with greater continuity associated with similar outcomes for each. Adjusted expenditures for beneficiaries cared for by physicians in the highest Bice-Boxerman continuity score quintile were 14.1% lower than for those in the lowest quintile ($8,092 vs $6,958; β = -0.151; 95% CI, -0.186 to -0.116), and the odds of hospitalization were 16.1% lower between the highest and lowest continuity quintiles (OR = 0.839; 95% CI, 0.787 to 0.893).

Conclusions: All 4 continuity scores tested were significantly associated with lower total expenditures and hospitalization rates. Such indices are potentially useful as QPP measures, and may also serve as proxy resource-use measures, given the strength of association with lower costs and utilization.

Keywords: continuity; measurement; primary care.

Figure 1

Distribution of physician-level continuity scores for 4 common individual measures.

Figure 1

Distribution of physician-level continuity scores for 4 common individual measures.

Figure 1

Distribution of physician-level continuity scores for 4 common individual measures.

Figure 1

Distribution of physician-level continuity scores for 4 common individual measures.

Figure 2

Physician characteristics associated with providing continuity of care (BB-COC), adjusted. (N = 6,551) BB-COC = Bice-Boxerman continuity of care; USMG = US medical graduate; IMG = international medical graduate. Notes: Source is 2011 Medicare Claims Data.1 Outcome is mean BB-COC score for patients receiving care from a primary care physician. See Supplemental Table 2 for regression results (Supplemental Table 2 available at http://www.annfammed.org/content/16/6/492/suppl/DC1/).

Figure 3

Association between physician-level continuity of care (BB-COC) and outcomes. BB-COC = Bice-Boxerman continuity of care; Q = quintile. Notes: Source is 2011 Medicare Claims Data.1 Outcomes are (1) the natural log of allowed patient charges, and (2) whether or not the beneficiary was hospitalized in in 2011. Multilevel analysis of 1,178,369 beneficiaries and 6,551 primary care physicians. Models include controls for physician and patient characteristics (see Supplemental Table 3, available at http://www.annfammed.org/content/16/6/492/suppl/DC1/).

Figure 3

Association between physician-level continuity of care (BB-COC) and outcomes. BB-COC = Bice-Boxerman continuity of care; Q = quintile. Notes: Source is 2011 Medicare Claims Data.1 Outcomes are (1) the natural log of allowed patient charges, and (2) whether or not the beneficiary was hospitalized in in 2011. Multilevel analysis of 1,178,369 beneficiaries and 6,551 primary care physicians. Models include controls for physician and patient characteristics (see Supplemental Table 3, available at http://www.annfammed.org/content/16/6/492/suppl/DC1/).