Trends in Outpatient Care for Medicare Beneficiaries and Implications for Primary Care, 2000 to 2019

Abstract

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.

Figure 1:. Patterns of Primary and Specialty Outpatient Care Use by Medicare Beneficiaries in 2000 and 2019

Panel A shows the annual mean number of office visits with either PCPs or specialist physicians per Medicare beneficiary in 2000–2019. Panel B shows the percentage of Medicare beneficiaries with any physician visit in 2000–2019. Panel C shows the annual mean number of distinct PCPs or specialists seen per Medicare beneficiary over the same period. Panel D shows the annual mean number of office visits with PCPs or specialists per Medicare beneficiary with any PCP or specialist visit, respectively, over the same period

Figure 2:. Number of Distinct Physicians Seen Annually by Medicare Enrollees, 2000–2019

Figure shows the percentage of Medicare beneficiaries who saw 0, 1–2, 3–4 or 5+ distinct physicians (both PCPs and specialists) in 2000–2019.

Figure 3:. Trends in Number of Physicians Treating a PCP’s Panel of Medicare Beneficiaries, 2000–2019

Panels A (line graph) and B (bar chart) show trends in the number of physicians treating a PCPs’ Medicare panel from 2000–2019, the median and inter-quartile range (25^th and 75^th percentile). The bar chart is shown to illustrate the final difference over the 20-year period. The number of other physicians seen by a PCP’s assigned Medicare patients is calculated by taking the number of other physicians seen annually (i.e. billing an evaluation and management visit or procedure) by all beneficiaries assigned to each PCP. Because our study population is limited to a 20% sample of Medicare beneficiaries, our measure may underestimate the absolute number of other physicians that would be calculated using data on 100% of a physician’s panel. However, analysis of network sampling for physician patient-sharing networks has found that 20% samples can reliably identify this value in claims data.(28)