The Arithmetic of the Panel: Why Primary Care Runs Out of Hours

Key Takeaways:

• A 2023 simulation study estimated that one primary care physician would need 26.7 hours per day to deliver all guideline-recommended preventive, chronic disease, and acute care, plus documentation and inbox work, to a representative panel of 2,500 adults.
• As early as 2003, researchers calculated that providing only the preventive services recommended by the US Preventive Services Task Force to a 2,500-patient panel would take 1,773 hours a year, or 7.4 hours of every working day.
• Direct Primary Care replaces insurance billing with a periodic membership fee, and practices commonly report panels of roughly 300 to 800 patients, an industry-reported range rather than a figure from peer-reviewed research.

Most people have felt the fifteen-minute visit: the physician who is kind but visibly behind schedule, the list of concerns that has to be trimmed to one, the question that occurs to you in the parking lot. It is tempting to blame individual doctors, but the real driver is a number most patients never hear, and that number is primary care panel size. A panel is the group of patients a physician is responsible for over time, not just the people seen on a given day, and every person on it generates work: screenings that come due, chronic conditions that need monitoring, sudden illnesses, test results, refill requests, and messages. Workload researchers typically model a conventional adult primary care panel at about 2,500 patients, and then ask a simple question. If a physician did everything the guidelines recommend for every person on that panel, how many hours would it take? The answer depends only on arithmetic: the number of patients, multiplied by how many recommended services each one needs in a year, multiplied by how long each service takes. When the product of those numbers exceeds the hours in a working day, something has to give, and what gives is usually time with each patient, the depth of each conversation, and the preventive care that never feels urgent until it is missed.

The first careful answer came in 2003. Applying every service recommended by the US Preventive Services Task Force, at the recommended frequency, to a 2,500-patient panel shaped like the US population, researchers estimated that prevention alone would require 1,773 hours of physician time a year, or 7.4 hours per working day, before a single sick visit. A companion analysis two years later took ten common chronic diseases and found that caring for them according to guidelines would take 3.5 hours a day if every condition were stable and well controlled, and about 10.6 hours a day once the extra time for uncontrolled disease was factored in. In 2023, a team revisited the whole question with updated guidelines and a panel built from national survey data, and added the modern burden of electronic documentation and the patient-message inbox. Their estimate was 26.7 hours per day: 14.1 hours for preventive care, 7.2 for chronic disease care, 2.2 for acute care, and 3.2 for documentation and inbox management. Even with a fully team-based model that delegates much of that work to nurses, health coaches, and other staff, the physician still needed an estimated 9.3 hours a day. A related modeling study found that with substantial delegation, a reasonable physician panel would fall to somewhere between about 1,400 and 1,950 patients.

What primary care panel size makes real care possible?

There is no single correct number, but the math points in one direction: fewer patients per physician means more time per patient, and time is the raw material of good primary care. Direct Primary Care is one structural answer. Instead of billing insurance visit by visit, a Direct Primary Care practice charges patients a periodic membership fee for primary care services, which removes much of the coding and claims work and changes the incentive from volume to relationship. A national description of these practices confirmed a broad geographic spread and relatively low price points, though it also noted that data on quality outcomes are still lacking. Practices commonly report panels of roughly 300 to 800 patients; that range comes from the industry itself rather than from peer-reviewed studies, but plugged into the same arithmetic, it helps explain why visits can run long enough to address several concerns, why same-day access is realistic, and why a physician can answer a message the day it arrives. The honest tradeoff is that small panels mean each physician cares for fewer people, which matters in a country already short of primary care clinicians, and larger outcome studies are still needed. Whatever model you use, it is fair to ask how many patients your physician is responsible for, because that number quietly shapes every visit you will ever have.

References:

1. Yarnall, K. S., Pollak, K. I., Østbye, T., Krause, K. M., & Michener, J. L. (2003). Primary care: Is there enough time for prevention? American Journal of Public Health, 93(4), 635-641.
2. Østbye, T., Yarnall, K. S., Krause, K. M., Pollak, K. I., Gradison, M., & Michener, J. L. (2005). Is there time for management of patients with chronic diseases in primary care? Annals of Family Medicine, 3(3), 209-214.
3. Porter, J., Boyd, C., Skandari, M. R., & Laiteerapong, N. (2023). Revisiting the time needed to provide adult primary care. Journal of General Internal Medicine, 38(1), 147-155.
4. Altschuler, J., Margolius, D., Bodenheimer, T., & Grumbach, K. (2012). Estimating a reasonable patient panel size for primary care physicians with team-based task delegation. Annals of Family Medicine, 10(5), 396-400.
5. Eskew, P. M., & Klink, K. (2015). Direct primary care: Practice distribution and cost across the nation. Journal of the American Board of Family Medicine, 28(6), 793-801.