Primary Care Use and Clinical Outcomes in a Prevalent Cohort of Patients Receiving Hemodialysis

Rationale & Objective: Primary care is associated with improved health outcomes, but whether this is true for patients receiving dialysis is unclear. We evaluated the association of primary care use in the previous year and clinical outcomes using a prevalent cohort of patients receiving hemodialysis. Study Design: Retrospective cohort study. Setting & Participants: United States Renal Data System registry of prevalent patients requiring maintenance in-center on January 1, 2019, linked with Medicare claims data. Exposure: Primary care use was defined as ≥ 1 outpatient visit to a provider with the specialty of Family, General, Geriatric, or Internal Medicine in the previous year (January 1, 2018, to December 31, 2018). Outcomes: All-cause mortality, cardiovascular mortality, infectious mortality, index hospitalization, emergency department/urgent care, and subsequent primary care visit. Analytical Approach: Inverse probability of treatment weighting (IPTW) to balance patients with primary care use with those without primary care use. Results: Among 122,496 patients (mean age, 65 years; 55% male; 59% White; 71% with diabetes), 60% had used, and 40% had not used, primary care services in the previous year. Primary care use was associated with lower rates of all-cause mortality (HR, 0.90; 95% CI, 0.88-0.92), cardiovascular mortality (HR, 0.96; 95% CI, 0.93-0.99), and infection mortality (HR, 0.81; 95% CI, 0.75-0.88). Primary care use was also associated with higher rates of first hospitalization (HR, 1.04; 95% CI, 1.02-1.05), first emergency department/urgent care use (HR, 1.06; 95% CI, 1.05-1.08), and subsequent primary care use (HR, 4.30; 95% CI, 4.21-4.39). Limitations: Residual/unmeasured confounding as well as limited generalizability given Medicare Primary Payer enrollment. Conclusions: Primary care use among prevalent patients requiring hemodialysis was associated with lower mortality but slightly higher rates of hospitalization and emergency department/urgent care visits.