Table 3.

Adjusted Associations Between Physician-Level Continuity of Care Quintile and Total Cost with Interactions with Patient Characteristics

CoC Interacting with	Physician-Level Continuity of Care Quintile^{^†}
CoC Interacting with	Quintile 3	Quintile 4	Quintile 5
Physician specialty
Internal medicine	−4.8% (−9.8%, 0.4%)	2.4% (−2.9%, 8.0%)	1.8% (−3.6%, 7.5%)
Pediatric medicine	−12.6% (−19.6%, −4.9%)^*	−17.0% (−23.8%, −9.6%)^*	−26.0% (−31.9%, −19.6%)^*
Family medicine	–	–	–
Primary payer
Medicare	1.6% (0.4%, 2.9%)^*	−1.0% (−2.3%, 0.2%)	2.8% (1.4%, 4.1%)^*
Medicaid	2.1% (0.4%, 3.8%)^*	8.7% (6.9%, 10.5%)^*	1.1% (−0.5%, 2.8%)
Commercial	–	–	–
Patient age^†
10 years older	−2.7% (−3.0%, −2.4%)^*	−2.8% (−3.1%, −2.5%)^*	−3.8% (−4.2%, −3.5%)^*
CCI (log)^†
1 point higher	−1.7% (−1.9%, −1.5%)^*	−2.4% (−2.6%, −2.1%)^*	−1.7% (−1.9%, −1.4%)^*
MARA (log)^†
1 point higher	1.8% (1.6%, 1.9%)^*	1.9% (1.8%, 2.0%)^*	1.6% (1.5%, 1.8%)^*

Abbreviations: CoC, continuity of care; CCI, Charlson’s comorbidity index; MARA, Milliman advanced risk adjusters.
Notes: Estimates of two-way interactions are shown, with all main effects (as in Table 2) included in the model.
↵*P < .05.
↵^†Quintiles 1&2 are reference category for CoC. Age centered at 53, estimate of 10-year increase. CCI centered at 0, estimate of 1 point increase. MARA centered at 1, estimate of 1 point increase.