Background: Despite the central role of primary care in improving health system performance, there are little recent data on how use of primary care and specialists has evolved over time and its implications for the range of care coordination needed in primary care.
Objective: To describe trends in outpatient care delivery and the implications for primary care provider (PCP) care coordination.
Design: Descriptive, repeated, cross-sectional study using Medicare claims from 2000 to 2019, with direct standardization used to control for changes in beneficiary characteristics over time.
Setting: Traditional fee-for-service Medicare.
Patients: 20% sample of Medicare beneficiaries.
Measurements: Annual counts of outpatient visits and procedures, the number of distinct physicians seen, and the number of other physicians seen by a PCP's assigned Medicare patients.
Results: The proportion of Medicare beneficiaries with any PCP visit annually only slightly increased from 61.2% in 2000 to 65.7% in 2019. The mean annual number of primary care office visits per beneficiary also changed little from 2000 to 2019 (2.99 to 3.00), although the mean number of PCPs seen increased from 0.89 to 1.21 (36.0% increase). In contrast, the mean annual number of visits to specialists increased 20% from 4.05 to 4.87, whereas the mean number of unique specialists seen increased 34.2% from 1.63 to 2.18. The proportion of beneficiaries seeing 5 or more physicians annually increased from 17.5% to 30.1%. In 2000, a PCP's Medicare patient panel saw a median of 52 other physicians (interquartile range, 23 to 87), increasing to 95 (interquartile range, 40 to 164) in 2019.
Limitation: Data were limited to Medicare beneficiaries and, because of the use of a 20% sample, may underestimate the number of other physicians seen across a PCP's entire panel.
Conclusion: Outpatient care for Medicare beneficiaries has shifted toward more specialist care received from more physicians without increased primary care contact. This represents a substantial expansion of the coordination burden faced by PCPs.
Primary funding source: National Institute on Aging.