Panel Size, Office Visits, and Care Coordination Events: A New Workload Estimation Methodology Based on Patient Longitudinal Event Histories

Background. Panel size, or the number of patients a primary care physician (PCP) and her care team can feasibly manage as part of a practice, remains a vital question in primary care. Objective. To Illustrate a new methodology for quantifying two types of workload associated with a panel size: 1) the PCP weekly office visit distribution and 2) the weekly distribution of non-PCP events (subspecialty visits, emergency room visits, hospitalizations) that potentially require non–face-to-face coordination. Methods. We assemble granular individual-level histories of events in the health system using the Medical Expenditure Panel Survey from 2011. Using the date on which each event occurred, we create weekly utilization estimates as a function of panel size for the general population and Medicare patients. Results. A PCP with a panel of 2,000 adults approximately representative of the US population can expect to have 93.54 office visits on average each week. A simple model quantifying demand–capacity mismatch suggests that a PCP with a weekly capacity of 80 to 90 appointments will struggle to satisfy this office-visit demand in a timely manner. Furthermore, each week the PCP can expect the same panel to have 9.08 visits to the emergency room, 4.69 hospital inpatient events, and 131.29 office-based visits to non–primary care subspecialists; these events contribute to the non–face-to-face coordination workload, increasing the probability of an overburdened workweek. Both PCP office visit and coordination events are highly concentrated in less than 200 individuals (<10% of the 2,000). Conclusion. Patient-level longitudinal event histories can be retrospectively assembled to quantify patterns of face-to-face office visits and coordination workload associated with a primary care panel.