Size Matters: What Is The Best Patient Panel Size For A Primary Care Physician?

In the past, we assessed how productive a primary care physician was by how many RVUs he or she generated. With the move toward accountable care organizations, quantity of visits is less important than value of care. Primary care physicians are often employed by hospitals or, in the case of academic medical centers, they are subsidized by the health system. So, we need to find another way other than RVUs to determine if the primary care physician is working at 100% effort.

One way of doing this is by the physician’s panel size. This is the number of patients that that physician is the primary care provider for. But there are a lot of problems with using panel size as a productivity metric because it is very easy to game the system. There are a lot of numbers thrown around about the optimal patient panel size. Historically, an often quoted number is 2,500 but this value was calculated on some flawed assumptions. More recently, many studies suggest optimal panel sizes from 1,300 to 1,900 per physician. So, what is the correct number? As with most things in medicine… it depends. There are a myriad of variables that affect the number of patients that a primary care physician should have in his/her panel. Here are a few:

1. Panel maturity. By that, I don’t mean how old the patients are but rather how long the physician has been seeing those patients. For a physician straight out of residency, every patient is a new patient and requires a lot more effort to get them plugged into specialists, a preventative medicine calendar, etc. Those new patient visits take a lot more time and often need shorter interval initial follow up visits. For a first year primary care physician to achieve a panel size of 1,900 in the first year out would require him/her to see 8-9 new patient visits per day and this is really not achievable.
2. Physician maturity. The more experienced the physician, the more efficient they get in the office. The same thing happens with ER physicians, hospitalists, and surgeons. A physician who has 20 years of practice experience can comfortably manage more patients than a physician straight out of residency.
3. Clinic maturity. Efficiency in patient flow and management is not just dependent on the experience of the physician but the experience of the nurses and office staff and how well they function together as a team.
4. Patient maturity. The intensity of primary care is age-dependent with the greatest intensity at either extreme of age. For a pediatrician, taking care of 1,500 children all under age 2 years old is a lot different than taking care of 1,500 13-year olds. Similarly for a family physician: a panel made up mostly of 25-year olds is much easier to manage than a panel the same size made up of 75-year olds. Geriatricians take care exclusively of the elderly and these are patients with more medical problems and psychosocial needs than working age adults; consequently, the geriatrician will have a smaller patient panel than a typical general internist.
5. Illness complexity. I know some primary care practices composed of a mixture of family practitioners, pediatricians, and internists. The children with more complex health needs, such as cerebral palsy and diabetes, are followed by the pediatricians. The adults with more complex health needs, such as advanced COPD and severe systolic heart failure, are followed by the internists. The rest of the patients are followed by the family medicine physicians. In this model, each patient gets assigned to the physician best equipped to take care of that patient but the pediatricians and the internists care for the most complex patients and generally require a smaller panel size than the family medicine physicians. Similarly, in a large primary care practice that has one physician who manages all of the patients with autism (who require more total physician time per patient per year), that physician will need to have a smaller panel size but taking care of all of the autistic patients, the other physicians will be able to handle larger panel sizes.
6. Use of advance practice providers. These are usually nurse practitioner or physician assistants. They may see patients independently, in which case they have their own panel of patients – usually smaller than the physicians. Or they may be used to amplify the productivity of the physician by performing less complex clinical tasks that free the physician up to manage more complex tasks. For example, a primary care physician may work with a nurse practitioner who does all of the routine health maintenance visits and preventive care visits thus freeing the physician up to see new patients and visits for new or acute problems. In this model, the physician can maintain a much larger panel size than the primary care physician who is a solo practitioner without a nurse practitioner. There is a solo family physician in our community who manages thousands of patients in an enormous multistory clinic building. He does it by employing an army of nurse practitioners and physician assistants and then he only sees those patients that the NPs or PAs have questions about.
7. Use of health specialists. Yes, the physician can spend an hour counseling a patient on a diabetic diet. But a dietician’s time is less expensive than a physician’s time. Having clinic staff who can teach patients how to use inhalers, monitor INRs to adjust Coumadin dose, do smoking cessation counseling can all free up the physician to do other activities. Therefore, dietitians, pharmacists, and health educators can equate to a larger panel size.
8. Health literacy of the patient population. The greater the health literacy of the patients, the easier it is to manage those patients and the easier it is to maintain a higher patient panel size. The same applies to access to healthcare of the patient – it is much simpler to manage a patient with good health insurance than it is to manage a patient with no insurance when it comes to getting medications, tests, and consultants.
9. The patients’ language. In my own practice, I take care of a lot of elderly Russian-speaking immigrants, French speaking patients from Africa, and Somalis. Each patient encounter takes longer because of additional time that it takes to communicate through a translator. Furthermore, the physician practice is generally responsible for arranging translation and this adds practice expense. The more non-English speaking patients in the panel, the smaller the panel size should be.
10. Office design. The physical structure of the clinic can have a huge impact on efficiency of patient flow and on how many patients can be seen. This translates to more patients that the primary care physician can comfortably manage in the panel. Having a sufficient number of exam rooms per physician plus easy access to basic testing such as x-ray, EKG, and lab equates to higher panel size.
11. Clinical education. Medical students represent the next generation of physicians and it is our professional obligation to ensure that the next generation is well-trained. However, medical students can slow you down since, for Medicare compliance purposes, the attending physician has to re-take the history, do a complete exam, and then do nearly all of the progress note documentation. That means that the clinical care time from the physician’s perspective is about the same whether there is a medical student or not, but once you factor in additional time to actually teach the medical student, the time costs add up. Fortunately, most physicians get inherent reward by educating students and so we would accept a smaller panel size, even it it meant a smaller salary, in order to be clinical educators.
12. The definition of who is in the panel. Our electronic medical record is great – it is very easy for me to see how many individual patients I saw in the office last year. However, if you use the EMR to calculate the panel size of a primary care physician by calculating how many individual patients that physician saw in the past year, you’ll get bad data. Inevitably, there will be times when the primary care physician will be cross-covering for a partner or will be taking acute illness calls or will be the physician in the office on the day that all of the practice’s patients come in for their flu shots. You have to have an accurate way of identifying those patients who are truly associated with each individual primary care physician as their physician of record.
13. Coordination of care with specialists. In a health system with good inter-physician communication with an electronic medical record and where specialists assume longitudinal management of specific medical problems, the time and effort required by the primary care physician for coordination of care is less and this translates to an ability to manage a larger patient panel. For example, if a patient is found to have pulmonary nodule and the primary care physician can refer that patient to a pulmonologist who will assume responsibility for further testing and follow-up of the nodule, then that frees up a lot of the primary care physician’s time. Some primary care physicians have a practice philosophy of “a consult is a sign of weakness” but these physicians can get tied up spending more time trying to manage highly specialized or complex diseases that could be managed more efficiently by coordinating management with a specialist.
14. Disease diversity. By this, I mean the homogeneity of the spectrum of health problems that the primary care physician sees. For example, being a general family physician is very challenging because you have to be familiar with the health maintenance requirements and preventive health needs for children all the way through the elderly. You have to be facile with gynecology (and sometimes obstetrics) as well as minor surgery. That is a lot of areas to keep up on from an education standpoint. This can limit the panel size. On the other hand, a primary care physician who limits their practice to one age group or one gender has a more focused patient population and in theory, can often manage a larger number of patients.

In summary, there is not a “one size fits all” when it comes to primary care physician patient panel size. My own take on panel size is that more than 2,500 is probably too many for the typical primary care physician and less than 1,000 is probably too few for the typical primary care physician. Whether an individual physician should have a panel size closer to 1,000 or closer to 2,500 depends on all of the variables above.

August 27, 2017